# Battery chat



## nukeadmin (Oct 10, 2003)

Hi,
In my MH I have at present 2 X 105ah batteries, now due to my full timing lifestyle and excessive power usage due to satellite systems, pcs etc I was thinking of boosting this somewhat. I approached a French dealer and asked if I could have another battery fitted in parallel with my existing 2. He hummed and ahhed and then stated as they only had 100ah batteries in stock, they wouldn't recommend adding a 100 to 2 existing 105ah setup as it would be an unbalanced setup. He instead recommended removing my existing, perfectly ok batteries and fitting 2 X 135ah instead.

Now i think he was blagging, in an attempt to extract more cash from me, can someone confirm whether or not it would be ok to add another slightly different rated battery to my setup ?


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## Anonymous (Nov 10, 2000)

I think your Frenchman may be speaking the truth. We have two 85ah and I wanted to upgade to 110ah. One would be a piece of cake however the second would not physically fit and would need a bit of work.

I thought of just doing the one for now but was advised not to. I can't remember who, might have been my dad, or why?

Useless information as such I know but hopefully someone will explain shortly. Mav 8)


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## 88792 (May 9, 2005)

If you have unequal batteries , when charging the higher rated ones will not receive a full charge, when the smaller one is charged it stops the others receiving more charge. Batteries must always be equal.


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## 90473 (May 1, 2005)

I was browsing around and came across this link

http://www.ukcampsite.co.uk/chatter...=12&TopicID=13603&PagePosition=1&ThreadPage=1

The posts by George Telford are particularly technical, therefore one naturally assumes that he knows his 'onions'. He may even be related to his namesake on this forum


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## Anonymous (Nov 10, 2000)

mikesha said:


> If you have unequal batteries , when charging the higher rated ones will not receive a full charge, when the smaller one is charged it stops the others receiving more charge. Batteries must always be equal.


Yes I remember it was something along those lines. Now why couldn't I have put it so easily :!: :!: :!:

Thanks Mike. :?


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## 88724 (May 9, 2005)

Hi Nuke,

Traction Batteries are by far the best in your situation, Have you got space for 6 2v Traction batteries? would it affect your warranty?

There are far too many unknowns, whats your charging system?, do you reside mainly on sites? (ie hooked-up), what is the longest period for which you require off site power? how often do you move? how long do you travel each move?

The usual motorhome system is built to be hooked up all the while you are away, ie Zig or plug-in systems power supply (sometimes called a charger in error!) and a relay to the alternator again it is mistakenly assumed that an alternator is a charging device, in fact an alternator is also a power supply, the idea being that it powers all the systems when moving and as a side effect puts enough charge into the battery to start the vehicle next time it is required, thats around 65% charged.

With a 100 ah leisure battery a lot of people assume that if it was running a device which required 10 amps that it would run said device for 10 hours, in reality even if the battery started off fully charged the longest you should run the device for is 5 hours, but unless you are using a good 3 or 4 stage charger the battery wont be fully charged anyhow, so say it has with normal motorhome charging system reached 70% charged the longest run is then 2 hours.

It does get worse though, If a battery is never fully charged and taken down to 50% or below regularly the plates gather sulphur which in turn makes it harder for the poor "charger" to recharge the battery! and a faster spiral downwards of leisure battery performance.

Its often asked why does a starter battery last longer like this? in the starter batteries situation although it is never fully recharged, it is only called upon to start the vehicle this tiny usage hardly uses any amp hours and is quickly replaced so it never really strays from being 65 -70% charged, all the time you are running the alternator is powering any devices run by the system.

If you regurlarly camped (year round) on hook up, the battery would last a similar time to the starter battery.

General motorhome usage tends to be for short periods and with long idle periods, this is why leisure batteries do not last long. 

There is no one answer that will suit everyone, unfortunately manufacturers only equip motorhomes as if there is. The reality is that there are so many different camping styles and most require different solutons, if you only camp on hook up sites and keep the batteries on trickle charge when stored, then a standard system as fitted will work. If you want to camp without hook up then you need a different solution.

George


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## nukeadmin (Oct 10, 2003)

> Traction Batteries are by far the best in your situation, Have you got space for 6 2v Traction batteries?


Why 2v batteries George ?
How big are they dimensions wise ?

btw your avatar is missing for some reason ?


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## 88724 (May 9, 2005)

Hi Nuke.










Thats what they look like, I have rang for some Info will post as soon as they reply.

Basically they will be a lttle bigger than the equivelent ah in ordinary 12v batteries, because the Plates are much thicker also each 2v cell is in its own case.

These have a life-span of 10 to 20 years. Heavy-duty traction versions can cope with an intensive, long term state of discharge. Complete expiry of the battery shortens the traction battery's life-span less than it does with the semi-traction versions. For daily intensive use a traction battery with a suitable three-stage charge system is the best system for full time use.


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## 88724 (May 9, 2005)

*Traction batteries*

Hi again

6 X 2v Cells Rated at 600ah would cost £724 +Vat and around £80 to deliver and fit (including all couplings)

weight for 6 600 ah cells is 192 KG

size for all 6 in a row is Height 431 mm Width 174mm and length 948

Compare this to say six leisures at £50 each = £300

Live aboard you would be lucky to get a year out of leisure batteries

With tractions you are talking 15-20 years, the initial cost is high but long term tractions will always win hands down.

The reason I use Leisure is because its not a full time vehicle, and with proper charging my batteries will last 5-7 years, full time use would eat my bank far too quickly.

a 300ah bank of tractions would cost less, £330 + VAT = £387 its all pretty much pro rata according to the sales desk at Barden. The fitting and delivery would not go down by the same amount.

With Traction you can use up to 80% of the rated capacity without harming then as much, so to get same capacity from leisures means having 500 ah of leisure batteries cost around £250 tractions costing £137 more for same bank will last 15 to 20 times longer !!

George


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## 88870 (May 10, 2005)

Wow George, you swallowed an electrical manual! You seem to have some serious info tucked away there. 8O 

All good stuff though, given some food for thought.

Fantastic avatar by the way  

Leigh


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## 88724 (May 9, 2005)

*Gell batteries*

You can lead a horse to water, but your pencil must be lead :wink:

I just received an email asking why not use Gell batteries ?

The one thing they always seem to mention when talking about gell batteries is that they can be used upside down, if ever I need to hang my batteries from the ceiling over a dinner table I might consider them (not)

A gell battery is basically a lead acid battery that can do a party trick (see above) the other thing they mention is that you can apply a charging ampage of up to half the rated capacity ie a 100 ah battery could have a charge ampage of 50A which seems like a good idea if you want to recharge quickly, again its not as good as it seems, because to stop the gell from gassing you have to apply a much lower voltage this lower voltage actually increases the charge time, more than the extra ampage can make up for, strike 2 for gell batteries.

The price of these is absolutly ridiculous and you gain nothing (worth having) over a lead acid battery.

George


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## Anonymous (Nov 10, 2000)

I have two 6v 100amp industrial gel cells which work well. They cost £19 each from www.bullnet.co.uk, this is a very interesting site and includes solar panels


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## Anonymous (Nov 10, 2000)

*battery chat*

Mmm, Just had a look at the Bull Electrical site and they do not have any batteries at that price now. They do have sealed lead acid high tech 6v 100ah at £27.50+ post.Still a good price for a quality battery.


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## Bazbro (May 9, 2005)

Some wonderful information there, George. Thanks. I've never heard of Traction batteries, so that's a great reply.

American sites recommend pairs of 6v golf cart batteries. Do you have any observations on these? Are they a type of Traction battery but with a different name?

Barry


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## 88724 (May 9, 2005)

Golf Cart batteries

Some Golf Cart Batteries are Traction batteries, but not all are.

Hi Rowley,

£19 each even for second hand is a bargain, all sealed or recombinant types suffer from the same problem has gell cells they have to have a special low voltage (hence slower) charge.

The only up side to these is that alternator (via split charge relay) charging and Zig type charging will put more ah into this type of battery, in all cases though a good lead acid with a good charger will outperform any of them.


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## 88724 (May 9, 2005)

*Stop the Presses*

Gell batteries are now not reccomended to be used upside down !!

So now they are Just expensive and slow to charge.

George

PS yes I am a little hard on gell batteries, but does anyone really want to spend 5 times more than standard lead acid for a battery which basically now as only one slim advantage? the only advantage it has left is, that it oozes rather than outright leaks if the case is split is that worth £200+ more ??

[/b]


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