Battery choice...

[Arnot]

OK, I have a question here…

 

Having taken a 25-year break from narrow boat electrics to pursue more technical avenues, I have now semi-retired and re-kindled my interest. Having read a lot of posts on this admirable forum I am a bit puzzled by the approach to domestic batteries.

 

When it comes to high capacity domestic storage battery banks, why do people seem to connect multiple 100Ah (ish) batteries in parallel? In most other industries that use batteries this is considered bad practice unless they will almost permanently be on a float charge and even then not ideal. Quite a few vehicle manufacturers have tried this over the years and all have quickly abandoned the idea having discovered that it leads to premature battery failure.

 

Surely if you are prepared to pay a reasonable amount of money and want longevity and capacity the best way would be to use six (or seven) large 2v cells connected in series. That way there is no possibility of current imbalance on charge and discharge and no possibility of parasitic discharge (when one battery discharges into another one connected in parallel with it). These are readily available in capacities up to 3000Ah.

 

Discuss…

 

Regards

 

Arnot

[flatplane8]

OK, I have a question here…

 

Having taken a 25-year break from narrow boat electrics to pursue more technical avenues, I have now semi-retired and re-kindled my interest. Having read a lot of posts on this admirable forum I am a bit puzzled by the approach to domestic batteries.

 

When it comes to high capacity domestic storage battery banks, why do people seem to connect multiple 100Ah (ish) batteries in parallel? In most other industries that use batteries this is considered bad practice unless they will almost permanently be on a float charge and even then not ideal. Quite a few vehicle manufacturers have tried this over the years and all have quickly abandoned the idea having discovered that it leads to premature battery failure.

 

Surely if you are prepared to pay a reasonable amount of money and want longevity and capacity the best way would be to use six (or seven) large 2v cells connected in series. That way there is no possibility of current imbalance on charge and discharge and no possibility of parasitic discharge (when one battery discharges into another one connected in parallel with it). These are readily available in capacities up to 3000Ah.

 

Discuss…

 

Regards

 

Arnot

 

 

Interesting, I'll be needing to build a battery bank for my boat and am trying to absorb all the information there is out there on them. Are the 2v cells you refer to basically forklift batteries? Can they be got in AGM types as well?

 

Thanks,

 

Simon

[Sir Nibble]

Cost. 12V batteries are freely and cheaply available, you could use the batteries from a submarine if you want, if you're a millionair.

On the subject of paralleling batteries, I do not believe it will cause any more problems with a fault in one effecting the others than series connection.

[larkshall]

Actually this is something I have also been thinking. But had thought of taking this further.

 

I seem to remember that diesel electric submarines used banks of 2 volt accumulators to provide the electric power. If a cell failed it could be replaced, or 'strapped out' of circuit in an emergancy. i don't know what the nominal voltage of a bank was (48-72volts?), but I suppose theoretically u could actually achieve 240v dc. Then again perhaps you could convert this to AC?. No inverters, now there is a thought. I know how deadly 240v dc can be, but come on you electrical gurus, A higher base voltage must have other savings?, (cable diameter?).........

[John Orentas]

Don't quite follow the reasoning behind all this, by any definition a 'Battery' is a bank of cells.. What difference does it make whether those cells are cute little individuals or families bonded together.

 

I agree with Snibble I doubt if there is a more economic way to store electrons than using mass produced car batteries.. The current going rate is better than 2a/h per £.

Edited May 7, 2008 by John Orentas

[larkshall]

I was thinking more along these lines

 

http://www.relocationspecialists.org/bat/cell.html

[John Orentas]

I was thinking more along these lines

 

http://www.relocationspecialists.org/bat/cell.html

 

 

Given that any bit of kit can go wrong, albeit on rare occasions.. On balance I think I would prefer a little 'pop' when a car battery cell jacks it in to an almighty KA---------POW when a 15,400 watt/hour submarine job decides to blow it's brains out.

[larkshall]

John, point taken, but they do come with a long life guarantee

[Chris-B]

John, point taken, but they do come with a long life guarantee

 

 

So go on then...HOW MUCH including the shipping ??

 

Chris

[denboy]

and this is generally the alternator that charges them

Siemens Alternator (Brand new!)

Type : IFC I/211/6hc62/z

Serial Number : GG93.000111/93036

Manufactured : 1993

Capacity : 3500 kVA @ 1000 RPM

Voltage : 6300

PF : 0.8Condition : Brand NewPrice : US$ 116,500 Only

[Gibbo]

OK, I have a question here…

 

snip

 

When it comes to high capacity domestic storage battery banks, why do people seem to connect multiple 100Ah (ish) batteries in parallel?

 

Because they are cheap.

 

In most other industries that use batteries this is considered bad practice unless they will almost permanently be on a float charge and even then not ideal.

 

It IS considered bad practice. However it's an old wives' tales. There NOTHING wrong with paralleling lead acid batteries. Submarines do it. Some other tpyes of batteries can be a problem in parallel. Lead acids are not.

 

Quite a few vehicle manufacturers have tried this over the years and all have quickly abandoned the idea having discovered that it leads to premature battery failure.

 

I'm not aware of any.

 

Surely if you are prepared to pay a reasonable amount of money and want longevity and capacity the best way would be to use six (or seven) large 2v cells connected in series.

 

They're good batteries but too expensive.

 

That way there is no possibility of current imbalance on charge and discharge and no possibility of parasitic discharge (when one battery discharges into another one connected in parallel with it).

 

That's another old wives' tale.

 

Gibbo

[Olitronic]

I looked into getting Traction Batteries, 6 x 2V 1000AH

 

Quote: £1200

 

 

I Went for 6 of the following AGMs at £300 for 600AH

 

http://cgi.ebay.co.uk/SLIMLINE-LEISURE-POW...1QQcmdZViewItem

 

The guy had 100's as he removes them from bank's ups's.

 

Not quite as good, but they will keep me going untill i have to decide again!

 

Been going 3 months on daily cycling of 150ish AH.

 

Aim never to take more than 50%, normally 33% to preserve battery life.

[Arnot]

Interesting, I'll be needing to build a battery bank for my boat and am trying to absorb all the information there is out there on them. Are the 2v cells you refer to basically forklift batteries? Can they be got in AGM types as well?

 

Thanks,

 

Simon

The sort of battery/cell I had in mind was something like these; Fiamm Batteries but I am sure that there are others. I have no idea what the price would be...

 

A few people have mentioned the fact that the conventional 12v batteries are a lot cheaper and in terms of purchase price I am sure that this is so. However if by paying twice a much you can get four times the service it may still be viable. I have used similar cells on other projects and some I installed eleven years ago are still going fine, on the other side, the cheaper leisure batteries only seem to last three or four years.

 

It was just an idea...

 

Regards

 

Arnot

 

Don't quite follow the reasoning behind all this, by any definition a 'Battery' is a bank of cells.. What difference does it make whether those cells are cute little individuals or families bonded together.

 

I agree with Snibble I doubt if there is a more economic way to store electrons than using mass produced car batteries.. The current going rate is better than 2a/h per £.

I am pretty sure that the normal 12v batteries are the cheapest way of creating a high capacity battery bank, I am just not sure if they are the most economic given the difference in lifespan.

 

I am not even proposing that 2v cells are a better solution, just wondering if they may be.

 

Does anyone know of any studies on this topic?

 

Regards

 

Arnot

[John Orentas]

"I am pretty sure that the normal 12v batteries are the cheapest way of creating a high capacity battery bank, I am just not sure if they are the most economic given the difference in lifespan.

 

I am not even proposing that 2v cells are a better solution, just wondering if they may be.

 

Does anyone know of any studies on this topic?"

 

 

I have never bought any other but the cheapest leisure batteries, (though I am still not convinced there is any difference from normal car batteries), over the past few decades they have averaged 7/8 years life.

 

Incidentally I have recently replaced the battery in my car, it was the original from new, 10 years old.

[davidandheather]

Hi we have Fiamm 2 volt wet traction batteries total amps 800 now in there 3rd year been ok so far.

Only thing i can say is you need to keep them topped up as the use a fair amount of water as they should according to the spec sheet. Also they take up less floor space than a load of car type batteries on the down side they are dam expensive but should have a lot longer life if looked after properly

You pays yer cash and takes your choice i know what i would buy

David

Edited May 7, 2008 by davidandheather

[Arnot]

I have never bought any other but the cheapest leisure batteries, (though I am still not convinced there is any difference from normal car batteries), over the past few decades they have averaged 7/8 years life.

 

Incidentally I have recently replaced the battery in my car, it was the original from new, 10 years old.

 

Thanks for the input John.

 

Do you live aboard (i.e. use the batteries a lot) or do you have the boat shorelined when not in use (a multi stage charger may well prolong the life of a battery)?

 

Is your car a Vauxhall or is the battery located away from the engine compartment. A few years ago I was involved peripherally in a study of the lifespan of car batteries and the determinant factors for failure and two findings stood out. One was that the Delco batteries fitted to the GM range seemed to outlast the average by nearly 100% the other was that the same battery starting the same engine lasted about twice as long if it was located at the back of the car rather than under the bonnet.

 

Regards

 

Arnot

[sueanddaren]

IDoes anyone know of any studies on this topic?

 

Regards

 

Arnot

 

Arnot

 

Try reading the battery mans bible its a book by a guy called Vinal (storage batteries). After that all will be clear, for keeping up with the latest info try Batteries International ,its a quarterly mag. But to sum it all up batteries are like engines you can buy an RN or a Gardner and it will last for ever. But because of cost most buy modified automotive engines, smaller cheaper but they don't last as long. Same with batteries.

 

As regards the submarine batteries don't believe all you see on that web site, they are only used in a sub for a max of 7/8 years. The ones you see for sale here are US exide types, crude crude crude. When I first got to take one to bits I thought it was a joke at first. Every European manufacturer has done better since 1950.

 

Regards

 

Daren

[alan_fincher]

Is your car a Vauxhall or is the battery located away from the engine compartment. A few years ago I was involved peripherally in a study of the lifespan of car batteries and the determinant factors for failure and two findings stood out. One was that the Delco batteries fitted to the GM range seemed to outlast the average by nearly 100% the other was that the same battery starting the same engine lasted about twice as long if it was located at the back of the car rather than under the bonnet.

We have a Ford Fiesta, bought new over 12 years ago.

 

It's original battery has just been replaced, not because it was definitely shot, but because it failed to start just the once after we had returned from a holiday abroad, (started fine first time when taken out of garage, but not when we tried to start it again a few minutes later). Recharged it, and it seemed fine, but not wanting to risk a breakdown, bought a new one anyway.

 

Battery is in conventional position under bonnet, and main use is short trips in traffic, where there are no long runs to guarantee it's as fully charged as it can be.

 

I think battery technology must have improved leaps and bounds over the years - If anyone had suggested to me in the 1970s or 1980s that I'd get over 12 years out of a car battery, I'd have laughed my socks off. (Mind you I guess the use of alternators now, versus the dynamos on cars of the past, gives you a better chance of having a well charged battery).

Edited May 7, 2008 by alan_fincher

[John Orentas]

We have a Ford Fiesta, bought new over 12 years ago.

 

It's original battery has just been replaced, not because it was definitely shot, but because it failed to start just the once after we had returned from a holiday abroad, (started fine first time when taken out of garage, but not when we tried to start it again a few minutes later). Recharged it, and it seemed fine, but not wanting to risk a breakdown, bought a new one anyway.

 

Battery is in conventional position under bonnet, and main use is short trips in traffic, where there are no long runs to guarantee it's as fully charged as it can be.

 

I think battery technology must have improved leaps and bounds over the years - If anyone had suggested to me in the 1970s or 1980s that I'd get over 12 years out of a car battery, I'd have laughed my socks off. (Mind you I guess the use of alternators now, versus the dynamos on cars of the past, gives you a better chance of having a well charged battery).

 

I have never had any great power usage, mine was always a weekend and holiday boat, but I don't see that as particularly significant, I have never had an external regulator either, I have always considered that a good size quality alternator with a greater than 14 volt output that nobody has hacked about is probably better than anything.

 

Yes I too have a thing about electrical systems and high temperatures, I have bored the forum members for years on the matter. It happens my car is a Mercedes with the battery in the boot.

Edited May 8, 2008 by John Orentas

[Arnot]

I have never had any great power usage, mine was always a weekend and holiday boat, but I don't see that as particularly significant, I have never had an external regulator either, I have always considered that a good size quality alternator with a greater than 14 volt output that nobody has hacked about is probably better than anything.

 

Yes I too have a thing about electrical systems and high temperatures, I have bored the forum members for years on the matter. It happens my car is a Mercedes with the battery in the boot.

Thanks for the response John, I am trying to see if there is any provable correlation between battery usage and battery life or at least what it is now.

 

My impression is that a weekend boat that is normally shorelined with a good battery charger would be likely to have a longer battery life. As stated in another post, battery life now seems far longer than it used to be but on average how long is it? The answer to this would have a bearing on my first question.

 

My impression is that a live aboard would have it's batteries cycled more deeply and more often. It used to be that this reduced the lifespan of the batteries significantly but I am no longer sure this is the case especially with the AGM and Gel types.

 

On the matter of regulators - I agree with you, if you ain't got a problem, why try to fix it?

 

Regards

 

Arnot

[GSer]

I looked into the fitting of 2v knife cells to a boat (i used to be a forktruck engineer so had at the time good access to reduced cost cells)

 

What put me off was the charging issues, if you had a shore line with a good supply (mine available at the time was 5amp, not enough ) then the traction battery idea seemed to be workable, however once cruising i was concerned that they would be more of a problem to keep fully charged. Another issue was that the extra height of the cells meant that in my boat (cruiser stern) fitting would have been an issue (they would just fit but leave little room for fresh air to circulate the hydrogen produced during charging or indeed any access for maintainance)

 

Paul

[davidandheather]

Hi

The height issue is a + point for me as they are in a locker on the stern in a semi trad

My 90amp alternator has no problems charging them up as you take no more out of them than ordinary batteries normally around 120 amps a night they are fully charged after a couple of hours running the engine.

Cheers David

[Sir Nibble]

I looked into the fitting of 2v knife cells to a boat (i used to be a forktruck engineer so had at the time good access to reduced cost cells)

 

What put me off was the charging issues, if you had a shore line with a good supply (mine available at the time was 5amp, not enough ) then the traction battery idea seemed to be workable, however once cruising i was concerned that they would be more of a problem to keep fully charged. Another issue was that the extra height of the cells meant that in my boat (cruiser stern) fitting would have been an issue (they would just fit but leave little room for fresh air to circulate the hydrogen produced during charging or indeed any access for maintainance)

 

Paul

I was also interested in using Nife cells and was put off by their lower efficiency. It may be possible of course to get around that, I was taught that it is not possible to over charge them, and I have no idea of their tolerance for voltage. Anyone know how much you can cram electrons down the gullet of one of these things?

Oh yea, Nife cells are 1.5V are they not?

Edited May 8, 2008 by snibble

[sueanddaren]

I was also interested in using Nife cells and was put off by their lower efficiency. It may be possible of course to get around that, I was taught that it is not possible to over charge them, and I have no idea of their tolerance for voltage. Anyone know how much you can cram electrons down the gullet of one of these things?

Oh yea, Nife cells are 1.5V are they not?

 

Snibble

 

Nife was/is a brand name, but they mainly made Ni/cad's, but they also did some Lead Acid. Like all cells there is a top voltage ie top of charge voltage that no amount of cramming will over come, on Lead acid its 2.9 to 2.7 Vpc (design dependent) and with Ni/cad's its 1.7 to 1.9 (again design dependent). Unfortunatly at these voltages the electrochemistry is very in-efficent at the latter end. But Im sure you already know that.

 

Daren

[Keeping Up]

Nife was/is a brand name

No it wasn't. It stands for Nickel/Iron cells (Ni = nickel, Fe = iron)