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.