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Battery Charger Installation
I'm about to install an onboard battery charger.
Is there any reason why the charging leads can not go to the ends of the battery cables at the selector switch instead of snaking into the box and being put on the terminals? This would be easier and neater and minimize the chance of things getting switched at battery change. When we put the batteries in, the yard made a good point. Switching one battery end for end so that either the two + or - terminals are side by side greatly minimizes the chance of a massive short if something gets across the terminals while the system is on. Everything should be dead whenever the box cover is off but this is real life and both boating and aviation are a good place for a belt and suspenders approach. -- Roger Long |
"Roger Long" wrote in message
... I'm about to install an onboard battery charger. Is there any reason why the charging leads can not go to the ends of the battery cables at the selector switch instead of snaking into the box and being put on the terminals? This would be easier and neater and minimize the chance of things getting switched at battery change. Makes sense to me and it removes the connection from the immediate vicinity of the batteries and the subsequent opportunity for corrosion from battery off gassing. Then you just have to keep the battery posts clean. Fuse them of course. When we put the batteries in, the yard made a good point. Switching one battery end for end so that either the two + or - terminals are side by side greatly minimizes the chance of a massive short if something gets across the terminals while the system is on. Everything should be dead whenever the box cover is off but this is real life and both boating and aviation are a good place for a belt and suspenders approach. Can't see any problem with this either. Roger Long -- Ken Heaton & Anne Tobin Cape Breton Island, Canada kenheaton AT ess wye dee DOT eastlink DOT ca |
Typically, the chargers are on the disconnect side and not the battery side.
The alternator is on the battery side. there should also be a large fuse between both and some sytems have a battery isolator too. "Ken Heaton" wrote in message news:8G1fe.28199$0X6.8978@edtnps90... "Roger Long" wrote in message ... I'm about to install an onboard battery charger. Is there any reason why the charging leads can not go to the ends of the battery cables at the selector switch instead of snaking into the box and being put on the terminals? This would be easier and neater and minimize the chance of things getting switched at battery change. Makes sense to me and it removes the connection from the immediate vicinity of the batteries and the subsequent opportunity for corrosion from battery off gassing. Then you just have to keep the battery posts clean. Fuse them of course. When we put the batteries in, the yard made a good point. Switching one battery end for end so that either the two + or - terminals are side by side greatly minimizes the chance of a massive short if something gets across the terminals while the system is on. Everything should be dead whenever the box cover is off but this is real life and both boating and aviation are a good place for a belt and suspenders approach. Can't see any problem with this either. Roger Long -- Ken Heaton & Anne Tobin Cape Breton Island, Canada kenheaton AT ess wye dee DOT eastlink DOT ca |
In that case, you would have to leave the battery switch on both to
leave the boat charging the batteries from shore power. I like the idea of being able to turn everything in the boat except the bilge pump completely off when not on it. I would have to rewire the bilge pump to the battery side to do that. That's the way I would like it but I will probably be chartering this boat eventually and I want to keep the set ups simple and standard. That's why I'm asking here what is typical. -- Roger Long "Phil Lewis" wrote in message ink.net... Typically, the chargers are on the disconnect side and not the battery side. The alternator is on the battery side. there should also be a large fuse between both and some sytems have a battery isolator too. |
Bilge pump should not be wired though a battery switch. If you have a
switch that even has a "both" position, then there is a better way. House bank should be unique with a separate starting battery. A switch to parallel the starting bank to the house bank in the case of an emergency is a good idea. DOug "Roger Long" wrote in message ... In that case, you would have to leave the battery switch on both to leave the boat charging the batteries from shore power. I like the idea of being able to turn everything in the boat except the bilge pump completely off when not on it. I would have to rewire the bilge pump to the battery side to do that. That's the way I would like it but I will probably be chartering this boat eventually and I want to keep the set ups simple and standard. That's why I'm asking here what is typical. -- Roger Long "Phil Lewis" wrote in message ink.net... Typically, the chargers are on the disconnect side and not the battery side. The alternator is on the battery side. there should also be a large fuse between both and some sytems have a battery isolator too. |
It's amazing how complicated simple things are when you start thinking
about them. A little research in Calder's book shows that he, at least, considers bilge pumps on the battery side common. But.. I've already decided to run both my batteries as close to parallel as possible to minimize the depth of the discharge cycles and get maximum life out of the expensive AGM cells. This goes against the conventional wisdom of always maintaining a dedicated starting battery. I'm going against the grain because: a.. This is a sailboat and I will not be helpless if the engine doesn't start. I've cruised in boats with no engine at all. b.. The engine can be hand started, at least in warm weather. c.. I'm going to be mostly daysailing and short cruising this year. d.. I have very minimal ship's service loads so it is unlikely that I'll run the batteries flat. e.. I can start this little engine with a portable emergency battery. It's even been done with a handful of flashlight batteries. So, if I want a dead ship except for the bilge pump, I have to decide which battery to use. That means that a long run of pumping with the charger off, as could happen with the boat unattended in a storm, would drain one battery down. I also would only have half the battery capacity for bilge pumping under the same circumstances. That is not ideal. Worse, if one battery did die, I would have to get into the panel and switch the bilge pump. That's not good. I guess that, for now at least, I'll just leave things as they are with the bilge pump wired into the bus. That means leaving the switch on "Both" when putting the boat away and being sure to turn everything except the bilge pump off. A good solution for my situation would be two bilge pumps, one on each battery. That would provide redundancy. It should be simple to run a second line and another through hull in this boat. I'll just wire them into the same float switch. I'm going to take a look tomorrow. We're doing a lot of through hull work anyway and we'll have the equipment right there to punch one in above the waterline. The ramifications just go on. I just realized that the bilge discharge fitting is 3/4 and the pump hose is 1 /18. That means there is a reducer somewhere. That's a kludge I'd better track down. That would be another reason to go to two pumps of the same total capacity. -- Roger Long "Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in message ... Bilge pump should not be wired though a battery switch. If you have a switch that even has a "both" position, then there is a better way. House bank should be unique with a separate starting battery. A switch to parallel the starting bank to the house bank in the case of an emergency is a good idea. DOug "Roger Long" wrote in message ... In that case, you would have to leave the battery switch on both to leave the boat charging the batteries from shore power. I like the idea of being able to turn everything in the boat except the bilge pump completely off when not on it. I would have to rewire the bilge pump to the battery side to do that. That's the way I would like it but I will probably be chartering this boat eventually and I want to keep the set ups simple and standard. That's why I'm asking here what is typical. -- Roger Long "Phil Lewis" wrote in message ink.net... Typically, the chargers are on the disconnect side and not the battery side. The alternator is on the battery side. there should also be a large fuse between both and some sytems have a battery isolator too. |
On Sat, 07 May 2005 11:00:11 GMT, "Roger Long" wrote:
I'm about to install an onboard battery charger. Is there any reason why the charging leads can not go to the ends of the battery cables at the selector switch instead of snaking into the box and being put on the terminals? This would be easier and neater and minimize the chance of things getting switched at battery change. When we put the batteries in, the yard made a good point. Switching one battery end for end so that either the two + or - terminals are side by side greatly minimizes the chance of a massive short if something gets across the terminals while the system is on. Everything should be dead whenever the box cover is off but this is real life and both boating and aviation are a good place for a belt and suspenders approach. Roger, the only concern I'd have is that chargers rely on knowing the "real" battery voltage. If you have load on the batteries while they are being charged, the extra voltage drop due to "remote" sensing might not be to your abvantage. Having said that, I suspect that with clean terminals and big cables the problem would be minimal. Norm B |
That's an excellent point. Exactly the kind of insight that prompted
my post. The cables in this case are about half an inch in diameter and three feet long. With just 10 amps of charging current per group 24 battery I agree that it won't be a problem. I cleaned up the battery connections bright and shiny when I put the batteries in and I'll do the other connections when I install the charger. -- Roger Long "engsol" wrote in message ... On Sat, 07 May 2005 11:00:11 GMT, "Roger Long" wrote: Roger, the only concern I'd have is that chargers rely on knowing the "real" battery voltage. If you have load on the batteries while they are being charged, the extra voltage drop due to "remote" sensing might not be to your abvantage. Having said that, I suspect that with clean terminals and big cables the problem would be minimal. Norm B |
"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
: Bilge pump should not be wired though a battery switch. If you have a switch that even has a "both" position, then there is a better way. House bank should be unique with a separate starting battery. A switch to parallel the starting bank to the house bank in the case of an emergency is a good idea. DOug Great advise, Doug. Lionheart has two battery switches, side-by-side. One selects which L-16 house battery bank, normally left in BOTH and the other selects which battery (starting or house or both) is connected to the diesel starter, normally left in STARTing battery. The house connection simply connects the starting switch to the common of the house switch. Set both switches to BOTH parallels everything in the boat, the ultimate jumper cables..(c; Of course, you can switch everything to OFF to unpower it all except the permanently-connected bilge pumps and battery chargers(one for house, one for starting). Bilge pumps and chargers connect through their own safety fuse block located on the side of the house battery boxes, directly connected BOTH NEGATIVE AND POSITIVE. Bilge pumps do NOT have an OFF position, which I consider REALLY STUPID in any boat! Stalled bilge pump blows the fuse, which has a neat 12V bulb across the fuse for EASY IDENTIFICATION. It'll light up the space until you press the new fuse into the holder. Why more don't do that remains a mystery to me. As to connecting the chargers upline from the battery posts, I'm against it. The chargers have enough trouble measuring the battery's voltage because they are wired so cheap by the manufacturers...i.e. such little wires. Every time a load current passes through the wires and corrosion from the battery switch, where the charger would be connected, to the battery, this voltage drop would be measured as an increased drop in battery voltage by the charger. This screws up the charging cycles. Nope, connect the chargers directly to the battery being charged without load current carrying wires in the path. For safety, Lionheart has a 100A fuse in the jumper link between the 6V batteries in series, one on each bank. Any shorts, except directly across one battery's terminals, would simply blow the fuse, not burn the boat to the waterline. 200A on #2 is a safe limit with the switch in BOTH and Amel has master breakers where we connect our wiring to the original boat French wiring. Starting the Perkins through one 100A fuse may blow it if the engine were locked, but doesn't when it is "normal" as we tried it. If there's any power left....we can crank it...(c; Any 12/24V fuse or breaker can have a trouble light on it, easy. Just wire an indicator light ACROSS the fuses in all circuits. The current through the load that blew the fuse will light the bulb. If the bulb is full brightness, it's a pretty good indication the load has a short to negative that needs to be cleared before you blow more fuses or retrip the breaker. I like the way it shows me what fuse/breaker is tripped while we're all sitting in the dark or in a dark engine room. I use bright red indicator lights that give me plenty of light to replace the fuse, but of course they go out or go dim when you clear the short. Just turn on the load and they'll light back up so you can see the fuse holders.....cheap at any Ratshack. |
Roger,
On goodly number of boats, I have done major reworks of the electrics. I always set it up so there is ONE (1) connection to each battery post. Attaching the charger and bilge pump leads to the disconnect is not a bad idea, just be certain to include an easy to locate fuse to limit the fault current in the smaller wire. Matt Colie Roger Long wrote: I'm about to install an onboard battery charger. Is there any reason why the charging leads can not go to the ends of the battery cables at the selector switch instead of snaking into the box and being put on the terminals? This would be easier and neater and minimize the chance of things getting switched at battery change. When we put the batteries in, the yard made a good point. Switching one battery end for end so that either the two + or - terminals are side by side greatly minimizes the chance of a massive short if something gets across the terminals while the system is on. Everything should be dead whenever the box cover is off but this is real life and both boating and aviation are a good place for a belt and suspenders approach. |
I've mentioned this befo you should simply parallel the bank and
install a small starting battery. If you want it to be high quality and "idiot proof" and a battery combiner (the smaller ones are cheap. Why invest in an "emergency" starter when the same money give you a proper solution? BTW, the small Yanmar will *usually* starts with under 5 seconds of cranking, but it isn't self bleeding, so it can get balky if the line gets dirty or airbound. I just started my two engines after winter layup - one fired quickly, but the other took about 30 seconds of cranking. My point is that in real life problems always come in groups - the morning your battery dies could also be the morning the fuel filter clogs. Why rely on a pack of D cells that cost the same as a proper battery? Roger Long wrote: It's amazing how complicated simple things are when you start thinking about them. A little research in Calder's book shows that he, at least, considers bilge pumps on the battery side common. But.. I've already decided to run both my batteries as close to parallel as possible to minimize the depth of the discharge cycles and get maximum life out of the expensive AGM cells. This goes against the conventional wisdom of always maintaining a dedicated starting battery. I'm going against the grain because: a.. This is a sailboat and I will not be helpless if the engine doesn't start. I've cruised in boats with no engine at all. b.. The engine can be hand started, at least in warm weather. c.. I'm going to be mostly daysailing and short cruising this year. d.. I have very minimal ship's service loads so it is unlikely that I'll run the batteries flat. e.. I can start this little engine with a portable emergency battery. It's even been done with a handful of flashlight batteries. So, if I want a dead ship except for the bilge pump, I have to decide which battery to use. That means that a long run of pumping with the charger off, as could happen with the boat unattended in a storm, would drain one battery down. I also would only have half the battery capacity for bilge pumping under the same circumstances. That is not ideal. Worse, if one battery did die, I would have to get into the panel and switch the bilge pump. That's not good. I guess that, for now at least, I'll just leave things as they are with the bilge pump wired into the bus. That means leaving the switch on "Both" when putting the boat away and being sure to turn everything except the bilge pump off. A good solution for my situation would be two bilge pumps, one on each battery. That would provide redundancy. It should be simple to run a second line and another through hull in this boat. I'll just wire them into the same float switch. I'm going to take a look tomorrow. We're doing a lot of through hull work anyway and we'll have the equipment right there to punch one in above the waterline. The ramifications just go on. I just realized that the bilge discharge fitting is 3/4 and the pump hose is 1 /18. That means there is a reducer somewhere. That's a kludge I'd better track down. That would be another reason to go to two pumps of the same total capacity. |
Roger Long wrote:
That's an excellent point. Exactly the kind of insight that prompted my post. The cables in this case are about half an inch in diameter and three feet long. With just 10 amps of charging current per group 24 battery I agree that it won't be a problem. I cleaned up the battery connections bright and shiny when I put the batteries in and I'll do the other connections when I install the charger. I'm glad you understand the significance of this issue, and it sounds like you won't have a problem. Single 0 (1/0) cable should handle 10 Amps for over 100 feet with less than a 2% drop. However, readers should be aware that a 100 Amp current will have a 2% voltage drop in 10 feet of single 0, and 14 feet of double 0. this will be a few tenths of a volt, enough to give a distorted reading of the charge state. In my case I have both a 100 Amp alternator and a 100 Amp shore charger. The shore charger is about 3 feet of 2/0 away, but the alternator is 15 feet. The next time I running it with a high rate I'll have to test the battery post voltage so see if its running higher than expected. |
On Sat, 07 May 2005 21:44:17 GMT, "Roger Long"
wrote: I've already decided to run both my batteries as close to parallel as possible to minimize the depth of the discharge cycles and get maximum life out of the expensive AGM cells. This goes against the conventional wisdom of always maintaining a dedicated starting battery. Modern electronic equipment can cause some annoyance/inconvenience when powered from the same battery as used to start the engine. When you start the engine, the battery voltage will drop significantly - this may be enough to turn off depth sounders and other things that have "soft" (electronic) power switches, and may cause microprocessor-based equipment to reset - your GPS may have to start from scratch re-acquiring satellites, and the radar will have to go through the 90 second warm-up routine again. Whether this is a serious problem, minor annoyance, or insignificant will depend on the equipment on board, the circumstances, and on the user.... -- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca |
I actually agree with all your points and it's probably the advice I'd
give someone else. However, I'm opting for simplicity and economy over the certainty of being able to start the engine in all circumstances. I'm not even going to invest in the emergency battery. The proper place for that, as you say, is in a box hooked up with the combiner, etc. My emergency propulsion for this year at least, will be good ground tackle and the willingness to wait for a wind. I'm going to try hand starting. If it does prove impossible I'll invest in a more sophisticated system. This is also a boat with no major electrical loads. I'll also be upgrading a lot of stuff before starting long cruises. This will be a duff around close to home and get to know the boat summer. I'll probably be spending a lot more time working on the systems than sailing. Aside from saving money, I'll have a much better idea at the end of the summer exactly what the boat needs and how I want to set up a more complex system. Even on a cruise Downeast, sailing in to anchor and rowing ashore to pick up a $40 car battery for a jump start wouldn't be a major emergency in this part of the world. Another two or three hundred dollars could be spent on much more critical things at this point than avoiding the slight possibility of that exercise. -- Roger Long "Jeff" wrote in message ... I've mentioned this befo you should simply parallel the bank and install a small starting battery. If you want it to be high quality and "idiot proof" and a battery combiner (the smaller ones are cheap. Why invest in an "emergency" starter when the same money give you a proper solution? BTW, the small Yanmar will *usually* starts with under 5 seconds of cranking, but it isn't self bleeding, so it can get balky if the line gets dirty or airbound. I just started my two engines after winter layup - one fired quickly, but the other took about 30 seconds of cranking. My point is that in real life problems always come in groups - the morning your battery dies could also be the morning the fuel filter clogs. Why rely on a pack of D cells that cost the same as a proper battery? |
After all the crap with the Capn and other trolls, it's nice to have a
discussion going on here where solid information comes back. My electronics outfit is pretty minimalist and the starting loads about as small as they get. Starting from the two battery bank shouldn't produce much drop with this little engine. This is confirmed by someone who has been running the same kind of boat for ten years this way. However, before installing radar or a hard mounted GPS, I will consider that adding a dedicated starting battery is an essential part of the installation. On this boat, I think I would go with the smaller size battery used in aircraft. If they will start the 320 cubic inch, 160 hp, engine in my 172, they ought to get this little diesel going. -- Roger Long "Peter Bennett" wrote in message news.com... On Sat, 07 May 2005 21:44:17 GMT, "Roger Long" wrote: I've already decided to run both my batteries as close to parallel as possible to minimize the depth of the discharge cycles and get maximum life out of the expensive AGM cells. This goes against the conventional wisdom of always maintaining a dedicated starting battery. Modern electronic equipment can cause some annoyance/inconvenience when powered from the same battery as used to start the engine. When you start the engine, the battery voltage will drop significantly - this may be enough to turn off depth sounders and other things that have "soft" (electronic) power switches, and may cause microprocessor-based equipment to reset - your GPS may have to start from scratch re-acquiring satellites, and the radar will have to go through the 90 second warm-up routine again. Whether this is a serious problem, minor annoyance, or insignificant will depend on the equipment on board, the circumstances, and on the user.... -- Peter Bennett, VE7CEI peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca |
Roger, I like your parallel bilge pump idea, but I'm not sure how you can
run this through one float switch as I've never heard of a DPST bilge switch. Is there such an animal available? Without it you will have difficulty isolating one battery bank from the other. I'm quite new to the sailing game and can't address many of your points, but I've risked my life and family in many other kinds of self-reliant endeavors and I've found that it is most important to rely on YOUR style of operation, not just "general practices". The row-in-for-a-quick-battery approach had me in stitches; not because I was laughing at you, but because it resembled my own unconventional, but practical, style of risk assessment: If you're not vulnerable, why be defensive! Padeen "Roger Long" wrote in message ... I actually agree with all your points and it's probably the advice I'd give someone else. However, I'm opting for simplicity and economy over the certainty of being able to start the engine in all circumstances. I'm not even going to invest in the emergency battery. The proper place for that, as you say, is in a box hooked up with the combiner, etc. My emergency propulsion for this year at least, will be good ground tackle and the willingness to wait for a wind. I'm going to try hand starting. If it does prove impossible I'll invest in a more sophisticated system. This is also a boat with no major electrical loads. I'll also be upgrading a lot of stuff before starting long cruises. This will be a duff around close to home and get to know the boat summer. I'll probably be spending a lot more time working on the systems than sailing. Aside from saving money, I'll have a much better idea at the end of the summer exactly what the boat needs and how I want to set up a more complex system. Even on a cruise Downeast, sailing in to anchor and rowing ashore to pick up a $40 car battery for a jump start wouldn't be a major emergency in this part of the world. Another two or three hundred dollars could be spent on much more critical things at this point than avoiding the slight possibility of that exercise. -- Roger Long "Jeff" wrote in message ... I've mentioned this befo you should simply parallel the bank and install a small starting battery. If you want it to be high quality and "idiot proof" and a battery combiner (the smaller ones are cheap. Why invest in an "emergency" starter when the same money give you a proper solution? BTW, the small Yanmar will *usually* starts with under 5 seconds of cranking, but it isn't self bleeding, so it can get balky if the line gets dirty or airbound. I just started my two engines after winter layup - one fired quickly, but the other took about 30 seconds of cranking. My point is that in real life problems always come in groups - the morning your battery dies could also be the morning the fuel filter clogs. Why rely on a pack of D cells that cost the same as a proper battery? |
Great info, Larry, I've been convinced about the dual battery switches since
I came up with the idea myself. : ), and I really like your light indicator application. As a commercial electrician I sometimes received odd looks when I announced the implementation of my most sophisticated and reliable measuring instrument - a 100w bulb in a pigtail - which told me more, in many cases, than a Fluke o-scope. But (and isn't there always a but), I don't understand your reasoning about the "little wires" in a charger. Yes, I'm aware of the Wal-mart mentality of cranking these units out with as little copper as possible (try jumping your car at -50 with a set of Walmart cables! Zip-cord has a new application.), but since no current (to speak of) passes through these during a hard start, and assuming correctly gauged wires to the battery switch, why would the charger react badly to a normal start? This is, one must assume, a start from a healthy battery. Padeen "Larry W4CSC" wrote in message ... "Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in : Bilge pump should not be wired though a battery switch. If you have a switch that even has a "both" position, then there is a better way. House bank should be unique with a separate starting battery. A switch to parallel the starting bank to the house bank in the case of an emergency is a good idea. DOug Great advise, Doug. Lionheart has two battery switches, side-by-side. One selects which L-16 house battery bank, normally left in BOTH and the other selects which battery (starting or house or both) is connected to the diesel starter, normally left in STARTing battery. The house connection simply connects the starting switch to the common of the house switch. Set both switches to BOTH parallels everything in the boat, the ultimate jumper cables..(c; Of course, you can switch everything to OFF to unpower it all except the permanently-connected bilge pumps and battery chargers(one for house, one for starting). Bilge pumps and chargers connect through their own safety fuse block located on the side of the house battery boxes, directly connected BOTH NEGATIVE AND POSITIVE. Bilge pumps do NOT have an OFF position, which I consider REALLY STUPID in any boat! Stalled bilge pump blows the fuse, which has a neat 12V bulb across the fuse for EASY IDENTIFICATION. It'll light up the space until you press the new fuse into the holder. Why more don't do that remains a mystery to me. As to connecting the chargers upline from the battery posts, I'm against it. The chargers have enough trouble measuring the battery's voltage because they are wired so cheap by the manufacturers...i.e. such little wires. Every time a load current passes through the wires and corrosion from the battery switch, where the charger would be connected, to the battery, this voltage drop would be measured as an increased drop in battery voltage by the charger. This screws up the charging cycles. Nope, connect the chargers directly to the battery being charged without load current carrying wires in the path. For safety, Lionheart has a 100A fuse in the jumper link between the 6V batteries in series, one on each bank. Any shorts, except directly across one battery's terminals, would simply blow the fuse, not burn the boat to the waterline. 200A on #2 is a safe limit with the switch in BOTH and Amel has master breakers where we connect our wiring to the original boat French wiring. Starting the Perkins through one 100A fuse may blow it if the engine were locked, but doesn't when it is "normal" as we tried it. If there's any power left....we can crank it...(c; Any 12/24V fuse or breaker can have a trouble light on it, easy. Just wire an indicator light ACROSS the fuses in all circuits. The current through the load that blew the fuse will light the bulb. If the bulb is full brightness, it's a pretty good indication the load has a short to negative that needs to be cleared before you blow more fuses or retrip the breaker. I like the way it shows me what fuse/breaker is tripped while we're all sitting in the dark or in a dark engine room. I use bright red indicator lights that give me plenty of light to replace the fuse, but of course they go out or go dim when you clear the short. Just turn on the load and they'll light back up so you can see the fuse holders.....cheap at any Ratshack. |
Given a sufficiently sized cable, the electrical equivalency will be equal.
"engsol" wrote in message ... On Sat, 07 May 2005 11:00:11 GMT, "Roger Long" wrote: I'm about to install an onboard battery charger. Is there any reason why the charging leads can not go to the ends of the battery cables at the selector switch instead of snaking into the box and being put on the terminals? This would be easier and neater and minimize the chance of things getting switched at battery change. When we put the batteries in, the yard made a good point. Switching one battery end for end so that either the two + or - terminals are side by side greatly minimizes the chance of a massive short if something gets across the terminals while the system is on. Everything should be dead whenever the box cover is off but this is real life and both boating and aviation are a good place for a belt and suspenders approach. Roger, the only concern I'd have is that chargers rely on knowing the "real" battery voltage. If you have load on the batteries while they are being charged, the extra voltage drop due to "remote" sensing might not be to your abvantage. Having said that, I suspect that with clean terminals and big cables the problem would be minimal. Norm B |
Good point, Jeff. Thanks. I'm quite familiar with 120 through 480 volt
drops, but it's nice to be reminded how dramatic 12v drops can be. Padeen "Jeff" wrote in message ... Roger Long wrote: That's an excellent point. Exactly the kind of insight that prompted my post. The cables in this case are about half an inch in diameter and three feet long. With just 10 amps of charging current per group 24 battery I agree that it won't be a problem. I cleaned up the battery connections bright and shiny when I put the batteries in and I'll do the other connections when I install the charger. I'm glad you understand the significance of this issue, and it sounds like you won't have a problem. Single 0 (1/0) cable should handle 10 Amps for over 100 feet with less than a 2% drop. However, readers should be aware that a 100 Amp current will have a 2% voltage drop in 10 feet of single 0, and 14 feet of double 0. this will be a few tenths of a volt, enough to give a distorted reading of the charge state. In my case I have both a 100 Amp alternator and a 100 Amp shore charger. The shore charger is about 3 feet of 2/0 away, but the alternator is 15 feet. The next time I running it with a high rate I'll have to test the battery post voltage so see if its running higher than expected. |
Roger,
You'd make it easier for us, and yourself, if you could identify those cables with a gauge # and class, rather than a diameter. Wire insulation varies dramatically with its class, allowing a range of conductor size within a specific measurement. For instance, XLP (insulation designation) may be as much as .02-.05in larger than THHN. Please don't take my post as criticism; I'm merely suggesting an alternative to wire descriptions by diameter. Roger Long" wrote in message ... That's an excellent point. Exactly the kind of insight that prompted my post. The cables in this case are about half an inch in diameter and three feet long. With just 10 amps of charging current per group 24 battery I agree that it won't be a problem. I cleaned up the battery connections bright and shiny when I put the batteries in and I'll do the other connections when I install the charger. -- Roger Long "engsol" wrote in message ... On Sat, 07 May 2005 11:00:11 GMT, "Roger Long" wrote: Roger, the only concern I'd have is that chargers rely on knowing the "real" battery voltage. If you have load on the batteries while they are being charged, the extra voltage drop due to "remote" sensing might not be to your abvantage. Having said that, I suspect that with clean terminals and big cables the problem would be minimal. Norm B |
"padeen" wrote in message
... Roger, I like your parallel bilge pump idea, but I'm not sure how you can run this through one float switch as I've never heard of a DPST bilge Yup, I just realized that with a groan. There is no substitute for sitting down and sketching out a schematic. Otherwise you end up focusing on only part of the picture as you stand in the marine supply store freaking out over how much it's going to cost you when the wife sees the credit card statement. If I weren't trying to keep battery drain parallel, I could just bring the wires of the two pumps together at the switch which has enough capacity for the amps. I'm using Rule's which (at least claim) to be very tolerant of running dry. The pumps are only a foot apart anyway. However, doing this with a pump on each battery would create a tie between the systems which would become the main battery lead if I turned the selector switch from both. FLASH BOOM! So, I'll be calling the store first thing this morning and telling them to send me another of those $40.00 switches. It's a good thing our marina lets you stay aboard because that's where I'll probably be sleeping this summer:) -- Roger Long |
No offence taken at all. I just hadn't looked for the cable sized yet
when I posted. My estimate was based on eyeballing the copper I could see at the terminals and did not include the insulation. The tie for the negative lead had disappeared and the yard made one up that was about half the diameter. It's short so this is probably OK but I need to verify that. Oddly, I used to design electrical systems for boats but it's been decades since I thought about them and my knowledge has leaked down to the level of the average bear. I now design some very sophisticated boats but someone else always worries about the electrical system. I just write specs saying that they shall be "first class, incredible, stupendous, and in accord with every know industry standard and manufacturer's recommendation." How do you like this one? http://home.maine.rr.com/rlma/odurv2.htm -- Roger Long "padeen" wrote in message ... Roger, You'd make it easier for us, and yourself, if you could identify those cables with a gauge # and class, rather than a diameter. Wire insulation varies dramatically with its class, allowing a range of conductor size within a specific measurement. For instance, XLP (insulation designation) may be as much as .02-.05in larger than THHN. Please don't take my post as criticism; I'm merely suggesting an alternative to wire descriptions by diameter. |
"padeen" wrote in
: why would the charger react badly to a normal start? This is, one must assume, a start from a healthy battery. Padeen Starting means nothing. The charger simply puts out all it can during starting, no matter how it's connected. I'm talking about leaving 20A of load running, the lights/fans/stuff. As long as the circuit is like new, no problem. But, this is a BOAT. Noone is going to pull apart the electrical system and clean all the connections every 6 months. Electrical systems on boats I meet are hard to get to, damned near impossible to pull apart and clean. Now that 20A load is operating through BOAT connections, all corroded from the bilge humidity, the occasional splash of seawater in the bilge on a rough day. Ahh...those are more reality. Now, the conveniently-connected charger is seeing a .5V drop from the battery switch to the battery, or wherever you have the charger connected. This subtracts from the battery's actual voltage every time someone turns on a light. So, the charger reacts by increasing its output more than the load needs to compensate. If it were independently connected to the battery, none of this would matter as the charging current isn't in the path with the load current. Someone else mentioned their AM/FM radio buzzing. The charger connected as you wish, not to the battery directly, will also cause any resistance in the path to the battery to modulate the DC with charger pulses, making electronics connected to it buzz or humm (or in the case of an alternator, whine). This is another case for connecting the charger directly to the battery posts, where the only way it will cause the buzz is if the battery has a dead cell. I'm an electronic technician. Another reason I don't like the charger connected upstream is safety for the expensive electronics on board. If any connection becomes loose between where the charger is connected and the battery, the charger's full pulse voltage WILL be applied to the DC power supply lines...18-22 volt pulses! This will destroy electronics. Unless the battery, itself, becomes open...a directly-connected charger cannot overvoltage the electronics. In your hookup, only one screw has to come loose or one connection opens with corrosion and blewee! |
I'm becoming convinced as well as educated. Certainly, the only place
I would connect the charger would be to the other end of big, fat, short, battery leads. I certainly wouldn't even do that if I had expensive electronics on board, was living aboard so that there was significant time with DC loads being drawn while charging, or charging via a generator. For our simple boat however, where everything will be off 95% of the time that it is plugged into shore power, I may still connect at the switch. I'll see which looks most convenient when I put the charger in and layout the leads. The charger I bought has a standard plug. Rebuilding my rudimentary AC panel so there is a switch for the charger is not in the cards. The yard suggested putting an outlet box in the engine room (can a place with no room be called a "room"). I would then have an outlet for a light or tools as well and could disable the charger when necessary. I'd appreciate your opinion on that Vs hardwiring. -- Roger Long |
"Roger Long" wrote in
: I'd appreciate your opinion on that Vs hardwiring. Boats never have enough AC outlets. There's some unwritten rule, I think. The Amel Sharki ketch had ONE in the galley! It had been converted from the Euro 220V outlet to 115VAC. It now has an outlet conveniently located next to the dual battery charger under the captain's bunk in the aft cabin....connected to two more AC outlets conveniently located to provide AC power where there was none. Every compartment has two or three AC outlets, now....(c; Being able to unplug the bad charger for its return to its dealer for replacement makes having it hard wired in a non-issue. Outlets are so easy to install and are so handy to plug that trouble light into.....instead of having that 50' yellow cord dragging over the decks. |
Roger,
There are several good reasons to set up the battery charger as a "plug-in": 1-If you have a problem with it, the unit is easily removed for repair or replacement. 2-Codes require a disconnect in sight of any piece of equipment and unpluging qualifies. 3-Code requirement ends at the outlet. I usually put a surface mount exterior plastic box local to the charger mount and have never been disappointed. Oh - by the by - no one out here on the sweat water (except some yard people) take corosion lightly. It isn't as bad as it is on the coast, but what would be a mess in a season there will take about three or fout here. Stores still sell a lot of 8-18 to people that know. (I bet I know whick jamoke a the marina hung the exhaust with galvanized strap.) Matt Colie Roger Long wrote: I'm becoming convinced as well as educated. Certainly, the only place I would connect the charger would be to the other end of big, fat, short, battery leads. I certainly wouldn't even do that if I had expensive electronics on board, was living aboard so that there was significant time with DC loads being drawn while charging, or charging via a generator. For our simple boat however, where everything will be off 95% of the time that it is plugged into shore power, I may still connect at the switch. I'll see which looks most convenient when I put the charger in and layout the leads. The charger I bought has a standard plug. Rebuilding my rudimentary AC panel so there is a switch for the charger is not in the cards. The yard suggested putting an outlet box in the engine room (can a place with no room be called a "room"). I would then have an outlet for a light or tools as well and could disable the charger when necessary. I'd appreciate your opinion on that Vs hardwiring. |
"Larry W4CSC" wrote in message ... "padeen" wrote in : why would the charger react badly to a normal start? This is, one must assume, a start from a healthy battery. Padeen Starting means nothing. The charger simply puts out all it can during starting, no matter how it's connected. I'm talking about leaving 20A of load running, the lights/fans/stuff. As long as the circuit is like new, no problem. But, this is a BOAT. Noone is going to pull apart the electrical system and clean all the connections every 6 months. Electrical systems on boats I meet are hard to get to, damned near impossible to pull apart and clean. Now that 20A load is operating through BOAT connections, all corroded from the bilge humidity, the occasional splash of seawater in the bilge on a rough day. Ahh...those are more reality. Now, the conveniently-connected charger is seeing a .5V drop from the battery switch to the battery, or wherever you have the charger connected. This subtracts from the battery's actual voltage every time someone turns on a light. So, the charger reacts by increasing its output more than the load needs to compensate. If it were independently connected to the battery, none of this would matter as the charging current isn't in the path with the load current. Someone else mentioned their AM/FM radio buzzing. The charger connected as you wish, not to the battery directly, will also cause any resistance in the path to the battery to modulate the DC with charger pulses, making electronics connected to it buzz or humm (or in the case of an alternator, whine). This is another case for connecting the charger directly to the battery posts, where the only way it will cause the buzz is if the battery has a dead cell. I'm an electronic technician. Another reason I don't like the charger connected upstream is safety for the expensive electronics on board. If any connection becomes loose between where the charger is connected and the battery, the charger's full pulse voltage WILL be applied to the DC power supply lines...18-22 volt pulses! This will destroy electronics. Unless the battery, itself, becomes open...a directly-connected charger cannot overvoltage the electronics. In your hookup, only one screw has to come loose or one connection opens with corrosion and blewee! This is another case for connecting the charger directly to the battery posts, where the only way it will cause the buzz is if the battery has a dead cell. I wish this was true. I have new batteries and my Xantrex / Statpower 20 amp chargers are connected directly to my house and starting batteries. I still get terrible static on my SSB and shortwave radios. Nothing on FM fortunately so at least I can listen to music in the evenings. |
Matt Colie wrote in
: 3-Code requirement ends at the outlet. Which is why your boat isn't covered, either... That's how they get away with that chinzy plastic AC power panel in the wooden box, or no box at all....instead of a proper fireproof electrical panel to keep it from burning to the waterline. DC power isn't covered, either. Your boat is plugged into the dock, where the code ends..... |
"Gordon Wedman" wrote in
news:Rmrge.61526$tg1.47034@edtnps84: I wish this was true. I have new batteries and my Xantrex / Statpower 20 amp chargers are connected directly to my house and starting batteries. I still get terrible static on my SSB and shortwave radios. Nothing on FM fortunately so at least I can listen to music in the evenings. This is caused by the RF radiation of the unshielded switching circuits in the chargers.....not by them actually pulsing a good, clean battery circuit. They radiate like hell on HF radio, a regular transmitter unto themselves. The wiring in the plastic boat is their antenna. You can minimize this radiation by stopping by Radio Shack and buying some ferrite chokes for the AC and DC cables to run through. RatShack has them in what's left of their depleted parts department. Get the square-looking one that opens up to put the cables through and put them as close to the charger as you can keep them. Looping one turn around them makes them work even better..... The best cure is if you have an old, reliable ferromagnetic or simple hand- controlled charger....KEEP IT! They don't radiate any RF signal at all, even at 40A of load.... |
Yeah, on our boat, you open up what looks like a locker while standing
in the galley with one hand in the sink and there's the bare AC smiling at you. I gotta do something about that. Until then, the shore power comes off before anyone steps aboard. -- Roger Long "Larry W4CSC" wrote in message ... Matt Colie wrote in : 3-Code requirement ends at the outlet. Which is why your boat isn't covered, either... That's how they get away with that chinzy plastic AC power panel in the wooden box, or no box at all....instead of a proper fireproof electrical panel to keep it from burning to the waterline. DC power isn't covered, either. Your boat is plugged into the dock, where the code ends..... |
On Sat, 07 May 2005 21:44:17 GMT, "Roger Long"
wrote: e.. I can start this little engine with a portable emergency battery. It's even been done with a handful of flashlight batteries. So, if I want a dead ship except for the bilge pump, I have to decide which battery to use. That means that a long run of pumping with the charger off, as could happen with the boat unattended in a storm, would drain one battery down. I also would only have half the battery capacity for bilge pumping under the same circumstances. That is not ideal. Worse, if one battery did die, I would have to get into the panel and switch the bilge pump. That's not good. Roger, I haven't read all this thread, so this may be repetitious, but why not abandon the starter battery altogether? Your set-up sounds like a good idea for these "crankable" starters http://www.startwell.com/ http://www.springstarter.com/index.htm http://www.dieselproducts.com/spring...r/pentham.html To my mind, I would use this as the primary starter on a small marine diesel (40 HP or less=over 50% of rec. sailboats), and keep the "traditional" solenoid-style starter vacuum-packed in the bilge. Subtract the requirement to turn over a cold diesel or even an Atomic 4 like mine (which I hand-crank once a year to keep in practice...), and you can rethink a lot of your electrical needs. Food for thought, anyway. R. |
"Larry W4CSC" wrote in message ... "Gordon Wedman" wrote in news:Rmrge.61526$tg1.47034@edtnps84: I wish this was true. I have new batteries and my Xantrex / Statpower 20 amp chargers are connected directly to my house and starting batteries. I still get terrible static on my SSB and shortwave radios. Nothing on FM fortunately so at least I can listen to music in the evenings. This is caused by the RF radiation of the unshielded switching circuits in the chargers.....not by them actually pulsing a good, clean battery circuit. They radiate like hell on HF radio, a regular transmitter unto themselves. The wiring in the plastic boat is their antenna. You can minimize this radiation by stopping by Radio Shack and buying some ferrite chokes for the AC and DC cables to run through. RatShack has them in what's left of their depleted parts department. Get the square-looking one that opens up to put the cables through and put them as close to the charger as you can keep them. Looping one turn around them makes them work even better..... The best cure is if you have an old, reliable ferromagnetic or simple hand- controlled charger....KEEP IT! They don't radiate any RF signal at all, even at 40A of load.... Thanks for the suggestions. I'll have a look for those ferrites. RatShack has them in what's left of their depleted parts department. Even worse up here since Intertan lost the rights to use the Radio Shack name. Went in a store the other day and the shelves were almost bare. |
"Gordon Wedman" wrote in news:fsNie.1426$wr.1275@clgrps12:
Even worse up here since Intertan lost the rights to use the Radio Shack name. Went in a store the other day and the shelves were almost bare. You can order ONE of any old thing, even one resistor, from www.mouser.com....if you're willing to pay the shipping. Mouser has all kinds of ferrite products: http://www.mouser.com/?Ne=100&handle...category&N=167 http://www.mouser.com/?handler=data....Ne=100&N=81016 (need metric diameter of the cable....less than $1 each?) Mouser online ordering is VERY responsive....Great company to buy electronics from.....I've been doing business with them for years after the parts stores in Charleston mostly closed up. |
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