| Page 1 of 2 | 1 | 2 |
|
|
How much power is in a 100ah battery
Stupid question time...
If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? |
How much power is in a 100ah battery
"Nigel" wrote in message ... Stupid question time... If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? If it is a "leisure" or deep discharge battery, then conventional wisdom is that it shouldn't drop below 50% of charge. This sort of battery would normally be used for the "domestic" stuff on your boat. A "normal" or engine-starting battery is designed to give high current for short periods of time, then be charged straight away, so it is more difficult to give a value. I don't suppose that has helped much. -- Steve Brassett |
How much power is in a 100ah battery
100AH is its total capacity. Normal rule of thumb is to only
discharge it down to 50%. So, you have 50AH of useful capacity. Doug s/v Callista "Nigel" wrote in message ... Stupid question time... If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? |
How much power is in a 100ah battery
|
How much power is in a 100ah battery
"Doug Dotson" wrote in message ... 100AH is its total capacity. Normal rule of thumb is to only discharge it down to 50%. So, you have 50AH of useful capacity. Doug s/v Callista Not quiet. Lets assume lead acid batteries and only engine charging. Yes the 50% of discharge is a generally acceptable figure, but you are unlikley to get them much above 80% of fully charged because we tend to use automotive alternator regulator designs that are built down to a price and not up to a duty (they do the job very well on a car). This means that you can only reliably assume 30% of usable capacity. The problem is that over the winter that 20% between 80% and 100% of fully charged will sulphate, which further reduces the capacity of the battery. To overcome this either charge with a mains charger that can charge to 100% or fit an advanced regulator that may reach 98% of fully charged. Tony Brooks "Nigel" wrote in message ... Stupid question time... If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? |
How much power is in a 100ah battery
Hi Nigel,
it depends on the type of battery, you are using: automotive batteries are made for short high current during starting, they should not been discharged more than 60...80%. In your case 80 AH discharging will be critical. marine batteries are made for slow and long discharging and they should not been discharged too much. Gel batteries should not been discharged more than 60 %, wet batteries not mote than 80 %. Take a look at the voltage, if you have a digital meter: battery voltage lower than 10.8 V will damage the battery (deep discharging). regards Juergen "Nigel" schrieb im Newsbeitrag ... Stupid question time... If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? |
How much power is in a 100ah battery
"Stefan" wrote in message ... In article , says... 100AH is its total capacity. Normal rule of thumb is to only discharge it down to 50%. So, you have 50AH of useful capacity. The advice for NiCad batteries for mobiles etc. is that it is good for them to go through complete discharge-recharge cycles. Anyone able to explain why lead/acid batteries are different - if indeed they are? I think - and it is only think, that it is to do with how the plates are constructed and move when they afre accepting or delivering high current flows. A lead acid battery has its plates made of a grid of lead latice upon which lead oxide powder is compressed, a bit like plastering a wall. When high currents are passed the plates actuall flex, the higher the current the greater the flex. Domestic batteries tend to have thick plates to give capacity, this means that when they flex the outer particles of the oxide are compressed or streached so tend to fall off. When they build up in the bottom of the cell and short a pos. & neg. plate the battery has failed. The flatter the battery the higher the charging current it will accept for any given charging voltage, so the more teh plates flex and the more they shed oxide. This explanation does for me, although there may be chemical one as well. This also explains why tubular plates (being curved so resisting flexing) tend to have a longer life than "normal" flat plate batteries. Tony Brooks |
How much power is in a 100ah battery
NiCads develop a memory over time and can't be fully recharged unless
they are fully discharged occasionally. Lead acid batteries don't develop a memory but do start to shed lead from the plates when they get very low. As a practical matter you really can't get more than about 35-40% of a wet cell's capacity out of a normal cycle while cruising. They should not be discharged more than 50 to 60% and when recharging that last 10-15% takes a long time. Up to about 80% you can safely push 25% of the capacity per hour back in but above that the rate of charge drops quickly. Stefan wrote: In article , says... 100AH is its total capacity. Normal rule of thumb is to only discharge it down to 50%. So, you have 50AH of useful capacity. The advice for NiCad batteries for mobiles etc. is that it is good for them to go through complete discharge-recharge cycles. Anyone able to explain why lead/acid batteries are different - if indeed they are? -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
How much power is in a 100ah battery
Nigel wrote:
Stupid question time... If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? batteries are USUALLY rated on a 10 hour cycle, so a brand new and fully charged 100Ah battery with put out 10 A for 10 hours, a 60 Ah battery will put out 6 A for 10 hours, and so on. The vast majority of batteries, eg car / domestic type, eg NOT deep cycle type as fitted to fork lifts and milk floats, will die VERY quickly if you deep cycle them, losing as much as 5% of their total capacity every time they are deep cycled, so a 2 year old 100 Ah battery that has not been deep cycled but has been used for engine starting may only have 75 Ah capacity left, given this I personally rate a 100 Ah battery as a 50 Ah battery to take this into account. Others are sure to disagree. -- Liquid Cooled PC? -- http://www.surfbaud.co.uk/ E-mail (rot-13) qnirahyy NG oyhrlbaqre QBG pb QBG hx EoF |
How much power is in a 100ah battery
On Wed, 16 Jun 2004 11:09:23 -0400, Guy Fawkes wrote:
Nigel wrote: Stupid question time... If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? batteries are USUALLY rated on a 10 hour cycle, so a brand new and fully charged 100Ah battery with put out 10 A for 10 hours, a 60 Ah battery will put out 6 A for 10 hours, and so on. snip Also worth mentioning that discharge at a higher current (ie over shorter time) will produce less amphours - doubling current drain might take 10percent off amphours. For this reason, batteries are often quoted at 20 hour rate (C20). Ian |
How much power is in a 100ah battery
In message , Stefan
writes In article , says... 100AH is its total capacity. Normal rule of thumb is to only discharge it down to 50%. So, you have 50AH of useful capacity. The advice for NiCad batteries for mobiles etc. is that it is good for them to go through complete discharge-recharge cycles. Only applies where a critical cut-off voltage is involved for the equipment. Otherwise "memory" is an urban myth Anyone able to explain why lead/acid batteries are different - if indeed they are? Tend to have steeper discharge curves and be used in non voltage critical applications -- Keith Lewis |
How much power is in a 100ah battery
Power is the time rate of energy use. Asking how much power is in a battery
is like asking how much velocity is in a full can of gasoline. There is no limit implied by the spec quoted. The Ah spec is usually given at the 20hr rate which is the time to discharge the battery to 1.75 V/cell (lead acid battery assumed) with a steady current draw, 5 amps in this case. For a 12 V battery this equates to 10.5 V. It is a non-linear relationship, halving the current will not double the discharge time. Battery manufacturers can provide curves or charts that show the actual Ah for different current draws. The spec is intended to represent usable capacity, since a battery can be recharged from 1.75V/cell with little loss of life. Deeper discharges will shorten life. Not too many real world loads are constant current. Lights will use less current as voltage drops (constant resistance), motors will use more (constant power.) "Nigel" wrote in message ... Stupid question time... If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? |
How much power is in a 100ah battery
"Nigel" wrote in message ... Stupid question time... If I have a 100ah battery how much power can I expect to get out of it... is 100ah the total battery capacity or it's useable/available capacity. My understanding is that a normal lead acid battery shouldn't be run too flat, so when is flat too flat? If I should only let my battery drain down to say a 90% charge, have I only got 10ah before I need to recharge? As a very basic answer, a 100 amp/hour battery should provide 100 amps for an hour or 1 amp for 100 hours, in reality of course it would probably melt if required to do the former. Then you need to factor in age, type of use, deep charge trickle or whatever. At best it is a guide only as to the possible maximum the battery can provide. |
How much power is in a 100ah battery
Guy Fawkes wrote:
snip ...so a 2 year old 100 Ah battery that has not been deep cycled but has been used for engine starting may only have 75 Ah capacity left... snip more Guy, you may be being pessimistic. My last car was scrapped complete with original (working) battery after 8 years & 120,000 miles. If I had lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it cranked fine - even when periodically I forgot to turn the immobiliser off so it didn't fire... Then again, I may have been lucky. Andy. |
How much power is in a 100ah battery
Ah capacity is only slightly related to cranking ability. A battery can be
significantly down on it's rated capacity yet still able to deliver adequate voltage for the typical period needed for starting an engine, even with the immobiliser. -- "Andy Champ" wrote in message ... Guy Fawkes wrote: snip ...so a 2 year old 100 Ah battery that has not been deep cycled but has been used for engine starting may only have 75 Ah capacity left... snip more Guy, you may be being pessimistic. My last car was scrapped complete with original (working) battery after 8 years & 120,000 miles. If I had lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it cranked fine - even when periodically I forgot to turn the immobiliser off so it didn't fire... Then again, I may have been lucky. Andy. |
How much power is in a 100ah battery
Andy Champ writes:
Guy Fawkes wrote: ...so a 2 year old 100 Ah battery that has not been deep cycled but has been used for engine starting may only have 75 Ah capacity left... Guy, you may be being pessimistic. My last car was scrapped complete with original (working) battery after 8 years & 120,000 miles. If I had lost 25% in 2 years, after 8 years I'd only have 30% left. Yet it cranked fine - even when periodically I forgot to turn the immobiliser off so it didn't fire... He was talking about deep-cycle batteries. They are not designed for extremely high current draw applications (such as engine starting). Just like starting batteries are not designed to be drawn way down. The difference is due to the plate design. A plate designed for providing cranking amps isn't good for deep cycle applications, and vice versa. Head to your local library and see if they have a copy of _Boatowner's Mechanical and Electrical Manual_ by Nigel Calder. The introduction in chapter one gives an excellent description of the difference between the two battery types. In fact, this is a "must own" book for any cruiser. I paid $80 (Canadian) for mine (second edition hardcover) and it was worth every penny. --lyndon |
How much power is in a 100ah battery
On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore
wrote: NiCads develop a memory over time and can't be fully recharged unless they are fully discharged occasionally. This is (almost) a myth. The Ni-Cad memory phenomenon does exist, but I can almost promise that no-one reading this has ever experienced it. It requires that the partial discharge/charge cycle be repeated *****EXACTLY***** many, many times. It was discovered in a satellite (and eventually duplicated) where the battery discharged for a precise length of time into a precise load, and then was recharged for a precise length of time at a precise rate. When the program of the satellite was changed later, it was found that the battery could not continue providing power after passing the previous discharge point. It simply won't happen just because you don't run a Ni-Cad down to zero before recharging it. In fact if you DO run it to zero, there is a very good chance that (because of slight differences in cell capacity) that you will reverse-charge one or more of the cells, which WILL ruin that cell quickly. Better to get it onto the recharger as soon as you experience a significant drop in output under load. At the point where your battery drill stalls at no load or very light load, you may well be pumping up one of the cells backwards as the other cells push the last few electrons through the load. The commonest way to damage Ni-cads, however, is to leave them on the charger too long, or to charge them too fast at some point in the recharge cycle. Every time this happens, the battery will lose some of it's capacity. |
How much power is in a 100ah battery
"Peter W. Meek" wrote in message ... On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore wrote: NiCads develop a memory over time and can't be fully recharged unless they are fully discharged occasionally. This is (almost) a myth. The Ni-Cad memory phenomenon does exist, but I can almost promise that no-one reading this has ever experienced it. It requires that the partial discharge/charge cycle be repeated *****EXACTLY***** many, many times. It was discovered in a satellite (and eventually duplicated) where the battery discharged for a precise length of time into a precise load, and then was recharged for a precise I Beg to differ with you. I have on occasions, and know friends who have damaged Ni-Cad batteries. They were damaged by partial depletion then recharging. They were in sealed waterproof torches and over a period of time the batteries were damaged by that method of charging. I now always run my batteries from full to empty no mater what type. taz. |
How much power is in a 100ah battery
I have also seen it happen...running wet cell NiCad's for a back up source
of power for cesium beam frequency standards. These units we periodically discharged and recharged as a preventative maintenance procedure, and they did develop memory. The fix was to vary the preventative maintenance discharge time/amount. H/P factory support helped us solve this problem. Doug K7ABX "taz" wrote in message ... "Peter W. Meek" wrote in message ... On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore wrote: NiCads develop a memory over time and can't be fully recharged unless they are fully discharged occasionally. This is (almost) a myth. The Ni-Cad memory phenomenon does exist, but I can almost promise that no-one reading this has ever experienced it. It requires that the partial discharge/charge cycle be repeated *****EXACTLY***** many, many times. It was discovered in a satellite (and eventually duplicated) where the battery discharged for a precise length of time into a precise load, and then was recharged for a precise I Beg to differ with you. I have on occasions, and know friends who have damaged Ni-Cad batteries. They were damaged by partial depletion then recharging. They were in sealed waterproof torches and over a period of time the batteries were damaged by that method of charging. I now always run my batteries from full to empty no mater what type. taz. |
How much power is in a 100ah battery
In message , taz
writes "Peter W. Meek" wrote in message .. . On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore wrote: NiCads develop a memory over time and can't be fully recharged unless they are fully discharged occasionally. This is (almost) a myth. The Ni-Cad memory phenomenon does exist, but I can almost promise that no-one reading this has ever experienced it. It requires that the partial discharge/charge cycle be repeated *****EXACTLY***** many, many times. It was discovered in a satellite (and eventually duplicated) where the battery discharged for a precise length of time into a precise load, and then was recharged for a precise I Beg to differ with you. I have on occasions, and know friends who have damaged Ni-Cad batteries. They were damaged by partial depletion then recharging. They were in sealed waterproof torches and over a period of time the batteries were damaged by that method of charging. I now always run my batteries from full to empty no mater what type. taz. Top-up charging is the best regime for NiCd's used in a torch. Full discharge every time simply wears out the cells unnecessarily. Of course cells vary enormously in quality and it is virtually impossible to buy decent ones from retail outlets. -- Keith Lewis |
How much power is in a 100ah battery
I Beg to differ with you.
I have on occasions, and know friends who have damaged Ni-Cad batteries. They were damaged by partial depletion then recharging. They were in sealed waterproof torches and over a period of time the batteries were damaged by that method of charging. I now always run my batteries from full to empty no mater what type. taz. Top-up charging is the best regime for NiCd's used in a torch. Full discharge every time simply wears out the cells unnecessarily. Of course cells vary enormously in quality and it is virtually impossible to buy decent ones from retail outlets. -- Keith Lewis I agree Keith there are a lot of variables to batteries and the way they are charged. The trouble with most set-ups IMHO is one cell will fail in the battery and then the battery as a unit starts to perform badly. Good cells are hard to get hold of and can easily be damaged by incorrect use. In my experience if a cell is sold with the label good for 2000 charge cycles I've found that, that number can be reduced by half if not even 3/4. So in real terms a battery that should be good for 2000 charges sometimes only last for 500 maybe 1000 charges. Not a scientific answer just my own experience. taz. |
How much power is in a 100ah battery
"Peter W. Meek" wrote in message ... On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore wrote: NiCads develop a memory over time and can't be fully recharged unless they are fully discharged occasionally. This is (almost) a myth. The Ni-Cad memory phenomenon does exist, but I can almost promise that no-one reading this has ever experienced it. I am sorry but you are not entirly correct. Proven many many times and easy to repeat. Take two brand new and identical radio controlled racing cars. FULLY charge and discharge the nicads of one of the cars ten times. Randomly and gently cycle the nicads of the other car ten times. Race the cars. Fully charged/discharged car WILL win. Not only will the car win a short sprint race... It will also win an endurance race. |
How much power is in a 100ah battery
On Thu, 17 Jun 2004 16:40:59 GMT, "Doug"
wrote: I have also seen it happen...running wet cell NiCad's for a back up source of power for cesium beam frequency standards. These units we periodically discharged and recharged as a preventative maintenance procedure, and they did develop memory. The fix was to vary the preventative maintenance discharge time/amount. H/P factory support helped us solve this problem. Doug K7ABX Well, I must admit, you ARE one of the very few who has experienced true "memory" in Ni-Cads. Taz will have to look elsewhere for his problems with his sealed waterproof torches. Unless he has found some way to discharge them partially AND IDENTICALLY each time (on for the exact same amount of time at the exact same temperature, EVERY single time) then it is something else that is reducing the capacity of his Ni-Cads. (They DO wear out under normal conditions, just not as soon and with as sharp a cut-off as when the memory effect is the cause.) |
How much power is in a 100ah battery
On Fri, 18 Jun 2004 10:01:19 +0000 (UTC), "James"
wrote: "Peter W. Meek" wrote in message .. . On Wed, 16 Jun 2004 10:34:33 -0400, Glenn Ashmore wrote: NiCads develop a memory over time and can't be fully recharged unless they are fully discharged occasionally. This is (almost) a myth. The Ni-Cad memory phenomenon does exist, but I can almost promise that no-one reading this has ever experienced it. I am sorry but you are not entirly correct. Proven many many times and easy to repeat. Take two brand new and identical radio controlled racing cars. FULLY charge and discharge the nicads of one of the cars ten times. Randomly and gently cycle the nicads of the other car ten times. Race the cars. Fully charged/discharged car WILL win. Not only will the car win a short sprint race... It will also win an endurance race. What you are seeing has nothing to do with "memory effect". A new nicad cell needs to be exercised several times to bring it up to its full capacity. The capacity as to charge / discharge cycles is sort of a bell shaped curve. Brand new not as much, after several charge discharge cycles the capacity peaks, then it starts declining with more charge discharge cycles. When discharging them you should never discharge them below about 1 volt per cell. Doing so you run the risk of a cell being reverse charged and that is the kiss of death for that cell. Also nicad's don't like to be float charged like a lead acid battery. A lead acid battery is as happy as can be when it is properly float charged. A nicad is not. It will kill them. A nicad is not the proper battery type for standby power. Don't let a nicad get too hot when charging as that will cause the cell to vent. Once a cell vents it is pretty much history. By the way, there is no such thing as "memory effect". The very early ni cad cells had sort of that problem but it does not exist in modern cells. Regards Gary |
How much power is in a 100ah battery
|
How much power is in a 100ah battery
On Fri, 18 Jun 2004 17:00:22 +0100, Stefan wrote:
In article , says... Also nicad's don't like to be float charged like a lead acid battery. What does "float-charged" mean? "Floating a battery" refers to keeping a constant voltage charge on the battery that is just high enough to replace the natural losses in the battery. This is typically done with lead acid batteries that are to be maintained at peak charge but not used for long periods. A fully charged 12 volt lead acid battery has a voltage of around 12.7 volts. It will slowly discharge itself with no load on it if left alone. If a constant 13.3 to 13.6 volts (depending on temperature) charge is left on the battery it will replace the self discharge energy of the battery. This voltage can be left on the battery indefinitely and will not harm the battery. Any higher charge voltage, only by a few tenths of a volt, for long periods will harm the battery. When initially charging the battery the voltage needs to be at around 14.2 volts for finishing the charge. Some gassing of the battery needs to take place in the final phase of charging, slight overcharging, in order to properly top off the cells. Then switch to the float voltage 13.3 volts to maintain. Regards Gary |
How much power is in a 100ah battery
"Doug" wrote in
nk.net: I have also seen it happen...running wet cell NiCad's for a back up source of power for cesium beam frequency standards. These units we periodically discharged and recharged as a preventative maintenance procedure, and they did develop memory. The fix was to vary the preventative maintenance discharge time/amount. H/P factory support helped us solve this problem. Doug K7ABX I remember that in HP freq standards, too, Doug. What lab do/did you work in? I'm a metrologist, too. Larry W4CSC Metrology Engineering Center (Code 132) Quality Assurance Office Charleston Naval Shipyard (may she rest in peace) |
How much power is in a 100ah battery
In message , taz
writes I Beg to differ with you. I have on occasions, and know friends who have damaged Ni-Cad batteries. They were damaged by partial depletion then recharging. They were in sealed waterproof torches and over a period of time the batteries were damaged by that method of charging. I now always run my batteries from full to empty no mater what type. taz. Top-up charging is the best regime for NiCd's used in a torch. Full discharge every time simply wears out the cells unnecessarily. Of course cells vary enormously in quality and it is virtually impossible to buy decent ones from retail outlets. -- Keith Lewis I agree Keith there are a lot of variables to batteries and the way they are charged. The trouble with most set-ups IMHO is one cell will fail in the battery and then the battery as a unit starts to perform badly. Good cells are hard to get hold of and can easily be damaged by incorrect use. In my experience if a cell is sold with the label good for 2000 charge cycles I've found that, that number can be reduced by half if not even 3/4. So in real terms a battery that should be good for 2000 charges sometimes only last for 500 maybe 1000 charges. Not a scientific answer just my own experience. taz. Agreed Cells are extremely variable and the ones on retail sale tend to give good ones a bad name. Many are in "D" size cases but are only around 1200 mAH as opposed to an average of 4000 mAH for those available to OEM's We've been manufacturing NiCd powered lighting for over 20 years and have been giving a 3 year guarantee for that time. We do however fit rather good ones:-) -- Keith Lewis |
How much power is in a 100ah battery
Agreed
Cells are extremely variable and the ones on retail sale tend to give good ones a bad name. Many are in "D" size cases but are only around 1200 mAH as opposed to an average of 4000 mAH for those available to OEM's We've been manufacturing NiCd powered lighting for over 20 years and have been giving a 3 year guarantee for that time. We do however fit rather good ones:-) -- Keith Lewis If I need NiCad cells now I use the ones that power emergency lights. They come pre-made into batteries and do seem to be of higher quality. taz. |
How much power is in a 100ah battery
In message , taz
writes Agreed Cells are extremely variable and the ones on retail sale tend to give good ones a bad name. Many are in "D" size cases but are only around 1200 mAH as opposed to an average of 4000 mAH for those available to OEM's We've been manufacturing NiCd powered lighting for over 20 years and have been giving a 3 year guarantee for that time. We do however fit rather good ones:-) -- Keith Lewis If I need NiCad cells now I use the ones that power emergency lights. They come pre-made into batteries and do seem to be of higher quality. taz. They tend to be "high temperature" versions (gets warm in emergency lighting luminaires) so separator design has to be good. Dendritic crystal growth through separators is the usual failure mode of Nicd's -- Keith Lewis |
How much power is in a 100ah battery
They tend to be "high temperature" versions (gets warm in emergency
lighting luminaires) so separator design has to be good. Dendritic crystal growth through separators is the usual failure mode of Nicd's -- Keith Lewis Is that a white powdery substance. Or I'm I just thinking of corrosion that forms on the aluminium casing sometimes. taz. |
How much power is in a 100ah battery
In message , taz
writes They tend to be "high temperature" versions (gets warm in emergency lighting luminaires) so separator design has to be good. Dendritic crystal growth through separators is the usual failure mode of Nicd's -- Keith Lewis Is that a white powdery substance. Or I'm I just thinking of corrosion that forms on the aluminium casing sometimes. taz. No its internal and causes tiny short circuits through the separator. Eventually these raise the self-discharge rate to unmanageable proportions ( but you will probably find that straight off charge you still get sufficient capacity). The cases are nickel plated steel -- Keith Lewis |
How much power is in a 100ah battery
No its internal and causes tiny short circuits through the separator.
Eventually these raise the self-discharge rate to unmanageable proportions ( but you will probably find that straight off charge you still get sufficient capacity). The cases are nickel plated steel -- Keith Lewis Right I must be getting confused then :-) Not hard I suppose. I understand what you are saying about the internal circuits now and as for the casing I obviously can't tell my nickel from my ally. Thinking back though and this is me trying to scratch back some resemblance of intelligence, our batteries were placed in aluminium bodied torches and with the added ingredient of see water it could of been that environment that was causing the corrosion inside the inside the torch and on the battery. Well that theory makes sense to me. Yeah good one taz. taz slinks of congratulating him self on how he pulled it back without any one noticing. ;-) Cheers taz. |
Using car battery in boat for limited time (was:How much power is in a 100ah battery)
As a very basic answer, a 100 amp/hour battery should provide 100 amps for
an hour or 1 amp for 100 hours, in reality of course it would probably melt if required to do the former. Then you need to factor in age, type of use, deep charge trickle or whatever. At best it is a guide only as to the possible maximum the battery can provide. As I normally daysail I do not need a battery in my boat. But when I occasionally cruise for a few days, I would like one, but only for the lights. I do not have other power consuming devices in my boat. So now the question is this: could I simply move my car's battery to the boat? Let's say for a four days cruise during summer time. Will it still start the car afterwards? I guess there will be the pleasant side-effect that the car will be less likely to be stolen. |
Using car battery in boat for limited time (was:How much power is in a 100ah battery)
"Jens K" wrote in message om... As a very basic answer, a 100 amp/hour battery should provide 100 amps for an hour or 1 amp for 100 hours, in reality of course it would probably melt if required to do the former. Then you need to factor in age, type of use, deep charge trickle or whatever. At best it is a guide only as to the possible maximum the battery can provide. As I normally daysail I do not need a battery in my boat. But when I occasionally cruise for a few days, I would like one, but only for the lights. I do not have other power consuming devices in my boat. So now the question is this: could I simply move my car's battery to the boat? Let's say for a four days cruise during summer time. Will it still start the car afterwards? I guess there will be the pleasant side-effect that the car will be less likely to be stolen. Please do a power audit (www.reading-college.ac.uk/marine) under course notes. This will tell you exactly how much electricity you need to store. Then decide if teh battery will still have enough capacity left to start the car in adverse conditions (my guess is no). If you do decide to go ahead with your proposed plan, please be aware that a car battery is constructed differently to those designed for the use you have in mind and you will shorten its life. If it is going to be by a measurable amount, I have no idea, butw ould not take the risk. I suspect a small leasure battery from a caravan shop and a split charge relay for the car (from the same source) would be your best bet. You could even just run a wire from the ignition switch to a croc clip in the boot to recharge the leasure battery whilst driving. Tony Brooks |
Using car battery in boat for limited time (was:How much power is in a 100ah battery)
"Jens K" wrote
So now the question is this: could I simply move my car's battery to the boat? Let's say for a four days cruise during summer time. Will it still start the car afterwards? I guess there will be the pleasant side-effect that the car will be less likely to be stolen. It'd be like leaving your car's interior lights on for four days. Would the car still start? Probably, but maybe not. (Mine didn't, leaving me stuck). Would the battery's life be shortened? Probably, but maybe not. |
Using car battery in boat for limited time
Bad idea. Car batteries are designed to produce a lot of power for a
few seconds and then be immediately recharged. They can survive being deeply discharged maybe 5 or 6 times before they die. Assuming you have a 25 watt anchor light burning 8 hours. That is 16 AH. Then you have 3 10 watt cabin lights burning 4 hours. That is 10 AH. Over a three night weekend that is about 75 AH. That will kill a group 27 auto battery in short order. You need 150 AH of battery minumum. The cheapest and longest lasting route would be a pair of $50 golf cart batteries from Wallymart, Sam's or Costco and a $60 charger with auto shutoff from Harbor Freight. You will eat that much in car batteries in one season. Jens K wrote: As I normally daysail I do not need a battery in my boat. But when I occasionally cruise for a few days, I would like one, but only for the lights. I do not have other power consuming devices in my boat. So now the question is this: could I simply move my car's battery to the boat? Let's say for a four days cruise during summer time. Will it still start the car afterwards? I guess there will be the pleasant side-effect that the car will be less likely to be stolen. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
How much power is in a 100ah battery
In message , taz
writes No its internal and causes tiny short circuits through the separator. Eventually these raise the self-discharge rate to unmanageable proportions ( but you will probably find that straight off charge you still get sufficient capacity). The cases are nickel plated steel -- Keith Lewis Right I must be getting confused then :-) Not hard I suppose. I understand what you are saying about the internal circuits now and as for the casing I obviously can't tell my nickel from my ally. Thinking back though and this is me trying to scratch back some resemblance of intelligence, our batteries were placed in aluminium bodied torches and with the added ingredient of see water it could of been that environment that was causing the corrosion inside the inside the torch and on the battery. Well that theory makes sense to me. Yeah good one taz. taz slinks of congratulating him self on how he pulled it back without any one noticing. ;-) Cheers taz. Sounds an excellent corrosive cocktail Cheers -- Keith Lewis |
How much power is in a 100ah battery
Well that theory makes sense to me. Yeah good one
taz. taz slinks of congratulating him self on how he pulled it back without any one noticing. ;-) Cheers taz. Sounds an excellent corrosive cocktail Cheers -- Keith Lewis Yes quite a stressful environment for the batteries I suppose. taz. |
| All times are GMT +1. The time now is 01:48 PM. |
|
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com