What should I have done to get better service from my new batteries?

[MtB]

Starter batteries are light (weight), used for high amps for a very short time, and recharge quickly.

 

proper domestic batteries are heavier, and discharged over a longer gradual time.

 

Forklift truck style batteries are very heavy, discharged to buxxery daily,, and last for years.

 

 

I dont understand why forklift batteries or trojans aren't standard leisure batteries on boats.

 

 

That's an easy one to answer. Most boaters are cheapskates!!

 

MtB

[cuthound]

Lead-Calcium batteries also degrade faster if over 50C.

 

I think this should be 25 degrees C. With the exception of aluminium/air batteries (which are one shot devices and have to be recycled rather than recharged), no battery will last long at 50C.

 

However the rest of Fosbergs post is excellent advice, so I expect it was a whisky induced typo

[Neil Smith]

I have had a quote for 6 fork lift batteries that are 540 amps at 5 hour rate and 2400 cycles with all the connecting cables and delivery was £ 675 so no need to be a cheapskate.

 

Neil

 

 

 

That's an easy one to answer. Most boaters are cheapskates!!

 

MtB

[nicknorman]

We are fairly heavy electrical users and, although not live aboard, use our boat quite a lot. When not in use, the batteries are on permanent float charge. In the first 3 yrs we got through 2 sets of "normal" unsealed leisure batteries. By the time I got the second set I knew a bit more about things and had an AH counter as well as a Smartgauge. However I found the capacity dropping substantially within the first 6 months. Equalising them fixed the problem, but gradually the interval between need EQ got shorter and in the end after around 2 years, it was clear that they had "had it" ie down to 50% capacity, not accepting charge well.

 

Set of Trojan T105s bought, 1 year later still at 100% of capacity. I did give them a minor EQ a couple of times, just for a couple of hours, but it wasn't really necessary.

 

I know that some folk manage to keep "leisure" wet lead acids going for years, but for me I would never go back to them. The price differential for Trojans is not massive. No brainer!

[DaveGood]

If the numbers the OP gave us in his first post are correct and not a typo, ( charging rate is 1 to to 2 amps per battery) then that is his problem, it's far to low.

 

On my boat we have 8 trojan t105's charged from a 110 amp alternator (actual amps output not known) plus a travel pack charging at around 80 amps. It takes between 2 to 3 hours daily to lift that battery bank (900 amp hours) from around 50% to 80 %..

 

I draw something like 15 to 20 amps per hour, charging at a rate of 1 to 2 amps per battery won't cover what my boat is currently using let alone charge up the batteries.

 

DaveGood

[Robbo]

If the numbers the OP gave us in his first post are correct and not a typo, ( charging rate is 1 to to 2 amps per battery) then that is his problem, it's far to low.

 

On my boat we have 8 trojan t105's charged from a 110 amp alternator (actual amps output not known) plus a travel pack charging at around 80 amps. It takes between 2 to 3 hours daily to lift that battery bank (900 amp hours) from around 50% to 80 %..

 

I draw something like 15 to 20 amps per hour, charging at a rate of 1 to 2 amps per battery won't cover what my boat is currently using let alone charge up the batteries.

 

DaveGood

 

Guessing a typo, as he says never exceeds 1A and then says dropped to 2A at xx% in a later in the same post

Edited January 22, 2015 by Robbo

[The Bagdad Boatman (waits)]

Two thoughts. How are your batteries linked? if live and earth for the bank come off one battery that one is being hammered. Do you have an alternator controller to keep charging up at 14v

[DaveGood]

Agreed Robbo,

 

But if that's the case, we don't have the info we need to offer anything useful in the way of advice.

 

The figures he quotes sound like what you would expect from the final (fully charged) batteries.

 

If he could tell us (estimate) how long it takes to put in a bulk charge from let us say 50% to 80% and at what sort of amps we'd be able to give him useful advice as to what sort of condition his batteries are in and what (if anything) he can do to improve matters.

 

As things stand he's told us he charges his batteries at a rate of 1 to 2 amps per battery. If that is really what he does then what he now owns three hundred pounds of lead scrap.

 

DaveGood

[DaveGood]

The Baghdad boatman makes avey good point.

 

When we bought our boat it had a string of five "liesure" batteries. Input (charging) was done via the first battery on the string, output (power take off) was done via the middle battery in the string, both of them failed real quick. Power in and out is best done with the positive connected to the first or last battery and the negative connected to the battery at the other end. Even then batteries won't charge and discharge at the same rate which means some will get more heavily hammered and "wear out" earlier then others.

 

It pays to physically swap the batteries around within the string every now and then.

 

I don't because to get at my battery bank I have to dismantle a ton of stuff.

 

DaveGood

[George94]

I think this should be 25 degrees C. With the exception of aluminium/air batteries (which are one shot devices and have to be recycled rather than recharged), no battery will last long at 50C.

 

However the rest of Fosbergs post is excellent advice, so I expect it was a whisky induced typo

 

I suspect he meant 50% SoC.

[DaveGood]

One further point,

 

I may be wrong but my understanding is that when you string together a battery bank, once you go over four batteries you will run into problems. Offhand I can't recall

Why,but it concerned the efficiency of charging and discharging, the 0P has seven.

 

Were I the OP and considering replacing his battery bank, I'd think about buying fewer, but bigger batteries.

 

DaveGood

[Robbo]

One further point,

 

I may be wrong but my understanding is that when you string together a battery bank, once you go over four batteries you will run into problems. Offhand I can't recall

Why,but it concerned the efficiency of charging and discharging, the 0P has seven.

 

Were I the OP and considering replacing his battery bank, I'd think about buying fewer, but bigger batteries.

 

DaveGood

If you still want a large bank, then using 6, 4 or 2v batteries is easier to balance wiring wise.

[DaveGood]

Which is what I've done with my eight 6 volt trojan t105's

 

DaveGood

[nicknorman]

Well I've said before, but might as well say it again. This whole "issue" with the interconnect topology is mostly myth IMO, provided the interconnects are adequate. We had our connection points to the battery at one end, but when I measured the current in each interconnect leg at high charge and discharge currents (ie around 150A) the flow from / to each battery was identical within the accuracy of the meter, as were the terminal voltages of each battery as measured with a digital voltmeter. Interconnects were 70mm^2, properly crimped.

 

It is only an issue if thin and/or badly connected interconnects are used.

[DaveGood]

You may well be right Nicknorman,

 

But the smartgauge website say's different. Admittedly they have a product to sell which means they need a problem for it to solve but I can't find a fault with the numbers they quote.

 

And according to them, if you wire up your battery inefficiently drawing off and recharging the bank via a battery at one end of of a four battery bank, which seems to be common and was pretty much true concerning the boat we bought, that battery will have to work more then twice as hard as the battery at the other end. Adding even more batteries to the string can only make that worse.

 

And wiring up a battery bank efficiently with oversized cables reduces, but does not solve the problem. We do what we can.

 

DaveGood

 

PS. I am not employed by, nor do I own, a Smartgauge.

Edited January 22, 2015 by DaveGood

[rogeriko]

I have had a quote for 6 fork lift batteries that are 540 amps at 5 hour rate and 2400 cycles with all the connecting cables and delivery was £ 675 so no need to be a cheapskate.

 

Neil

 

 

Finally someone with some sense!! I have been going on about this because I install houses with battery systems a lot larger than narrowboats, here are some photos to wet your appetite. https://www.flickr.com/search/?q=mykonos%20solar%20wind

 

Neil please give everyone the details of your quote.

 

When it comes to connecting lots of batteries together, even 2 or more, the problem is because every battery will have a slightly different INTERNAL RESISTANCE therefore they will not charge at the same rate no matter how you connect them. The battery with the lowest internal resistance will take more current than the others and charge quicker and get overcharged sooner. The battery with the highest internal resistance will charge slower and never reach full charge. Thats why its important to have one set of high amperhour batteries and be done with it. You dont see telecoms companys or computer backup companys with a room full of leisure batteries do you!

[nicknorman]

You may well be right Nicknorman,

But the smartgauge website say's different. Admittedly they have a product to sell which means they need a problem for it to solve but I can't find a fault with the numbers they quote.

And according to them, if you wire up your battery inefficiently drawing off and recharging the bank via a battery at one end of of a four battery bank, which seems to be common and was pretty much true concerning the boat we bought, that battery will have to work more then twice as hard as the battery at the other end. Adding even more batteries to the string can only make that worse.

And wiring up a battery bank efficiently with oversized cables reduces, but does not solve the problem. We do what we can.

DaveGood

PS. I am not employed by, nor do I own, a Smartgauge.

Sure, but the writing on the Smartgauge website are the views of one man - Chris Gibson. Just because something is found on the Internet, doesn't mean it was handed down from God!

 

I suspect you may have arrived at the forum after he left, but he was very, very opinionated. Certainly a lot of what he says is correct. But not all of it. We had an argument about this point on here, in the end I got him to admit that it was a non issue with good quality interconnects, but he maintained that the advice on the website was good because so many folk have bad interconnects - inadequate cable size and corroded connectors. He is right in that respect, but I would prefer to have adequate interconnects and keep them maintained, rather than stressing too much about equal lead lengths etc.

 

You mention the end battery "working twice as hard" but this is pure myth, presuming reasonable interconnects. As I said, at 150A (37.5A per battery) there was no detectable difference in the current going in and out, the current difference was less than 0.1A, hardly "working twice as hard". The rest of the battery cabling is 70mm^2 because of the 2.5kva inverter and 175A alternator, so I don't think using the same cable for the interconnects is oversizing.

Edited January 22, 2015 by nicknorman

[Loafer]

 

Finally someone with some sense!! I have been going on about this because I install houses with battery systems a lot larger than narrowboats, here are some photos to wet your appetite. https://www.flickr.com/search/?q=mykonos%20solar%20wind

 

Neil please give everyone the details of your quote.

 

When it comes to connecting lots of batteries together, even 2 or more, the problem is because every battery will have a slightly different INTERNAL RESISTANCE therefore they will not charge at the same rate no matter how you connect them. The battery with the lowest internal resistance will take more current than the others and charge quicker and get overcharged sooner. The battery with the highest internal resistance will charge slower and never reach full charge. Thats why its important to have one set of high amperhour batteries and be done with it. You dont see telecoms companys or computer backup companys with a room full of leisure batteries do you!

True enough, but even one single, large 12V battery is still six independent cells, wired in series inside the battery. One of those cells might well have a different internal resistance to it's neighbour, thereby introducing the same problem. At least with a bank, you can remove the offending 'cell'.

[MtB]

When it comes to connecting lots of batteries together, even 2 or more, the problem is because every battery will have a slightly different INTERNAL RESISTANCE therefore they will not charge at the same rate no matter how you connect them.

 

 

Not true.

 

I have a pair of 12v leisure batteries and I can GUARANTEE the charging current is the same in both. Always.

 

 

MtB

[nicknorman]

Not true.

 

I have a pair of 12v leisure batteries and I can GUARANTEE the charging current is the same in both. Always.

 

 

MtB

Series doesn't count!

[Loafer]

Series doesn't count!

Nice one, Centurion.

[dmr]

 

 

Not true.

 

I have a pair of 12v leisure batteries and I can GUARANTEE the charging current is the same in both. Always.

 

 

MtB

 

Yes, but what about the voltage across each cell ????????

[rogeriko]

 

 

Not true.

 

I have a pair of 12v leisure batteries and I can GUARANTEE the charging current is the same in both. Always.

 

 

MtB

 

If you had one old battery and one new one would the charging current be the same? All batteries are different thats why it is a problem to connect them in parrallel

True enough, but even one single, large 12V battery is still six independent cells, wired in series inside the battery. One of those cells might well have a different internal resistance to it's neighbour, thereby introducing the same problem. At least with a bank, you can remove the offending 'cell'.

 

 

The cells are connected in series therefore they will all conduct the same amperage, ie the amperage of the weakest cell. As above, series dosn't count its a different animal

[rogeriko]

I have had a quote for 6 fork lift batteries that are 540 amps at 5 hour rate and 2400 cycles with all the connecting cables and delivery was £ 675 so no need to be a cheapskate.

 

Neil

 

 

540 AmpHours at 5 hour rate is about equal to 700 AmpHours at 20 hour rate and about 900 AmpHours at 100 hour rate which is what most leisure batteries at rated at. Therefore they are actually cheaper than buying 8 110 leisure batteries.

 

2400 cycles means If you run them down and charge them up again every 4 days they will last for 26 years!!! 800/900 amphours is a lot of power

[MtB]

 

If you had one old battery and one new one would the charging current be the same? All batteries are different thats why it is a problem to connect them in parrallel

 

24v alternator.

 

MtB