Fitting 2nd Leisure battery. Questions......

[VXman]

I am wanting to fit a second leisure battery under the drivers seat. There's not a lot of room and certainly one identical to the original will not fit. I am aware of the importance of having matching batteries. I don't really want to dump the current one as it is brand new. If I can find one with the same technical
spec but a little smaller would that be OK? What are the important specifications to note - is it just the 95AH or are some of the other numbers important. (incidentally why dies this battery have 85ah on it too?)

Another possibility would be to put the 2nd battery nearby under the lounge seat. However this would a bit more than a metre away - is this too far?

Appreciate any knowledge/advice /suggestions.

 

[the1andonly]

Yes other numers are impotant
95ah
Amp Hour or C20 is an indicator of how much energy is stored in a battery. It is the energy a battery can deliver continuously for 20 hours at 80°F without falling below 10.5 Y
85ah c5 is 85ah if discharged over 5 hrs. Ie qucker discharge more amps less storage.

 

[Guigsy]

If the battery is the same chemistry, age, and ideally the same brand, does it matter if it's a lower capacity?

 

[the1andonly]

Edit Compare like with like, get ready for comments like bin that agm now ,at least its not a banner.

 

[pappajohn]

If the battery is the same chemistry, age, and ideally the same brand, does it matter if it's a lower capacity?

Nope, not a jot of difference. The system only sees one big battery, it doesn't know how many individual batteries make up the big one.
Same chemistry and similar age are important but nothing else matters.

As for the new one under the lounge seating, as long as the linking cables are large enough it makes little difference.
The further apart, the bigger the cables.

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[Jimbohorlicks]

I have 2 X 110 ah plus a 95 ah all different makes and ages.doesnt seem to make any difference.they all charge up ok and I have 12.7 v with 315 ah and 200w solar. Whilst it may be preferable to have all the same ,it's not always practical or necessary.

 

[autorouter]

If the two batteries are not right next to each other, the positive link cable needs to have a fuse at both ends, near each battery. Use extra thick cables to link them - not for safety, but to minimise voltage drop.

 

[John H.]

And if you have the enthusiasm connect the charge/load connections as shown here for a better battery balance.

Don't forget the fuses needed but not shown in this diagram.

All of the cables should be capable of carrying the maximum load.

 

[VXman]

Nope, not a jot of difference. The system only sees one big battery, it doesn't know how many individual batteries make up the big one.
Same chemistry and similar age are important but nothing else matters.

As for the new one under the lounge seating, as long as the linking cables are large enough it makes little difference.
The further apart, the bigger the cables.

Ah - that is interesting. Struggling to get a 2nd battery to fit. So It's ok to get a 70ah battery (for example) and connect that to the 95ah. If that's the case that would open up my options.

 

[Jamesh]

If the two batteries are not right next to each other, the positive link cable needs to have a fuse at both ends, near each battery. Use extra thick cables to link them - not for safety, but to minimise voltage drop.

Halfords do ready made crimped battery cables in various lengths saves having to make them up. About £5 each...

Cheers James

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[Jamesh]

Ah - that is interesting. Struggling to get a 2nd battery to fit. So It's ok to get a 70ah battery (for example) and connect that to the 95ah. If that's the case that would open up my options.

Sure if the chemistry is the same.

Cheers James

 

[Abacist]

Varta make great batteries!

 

[autorouter]

What are the important specifications to note - is it just the 95AH or are some of the other numbers important.

If you are comparing batteries by different manufacturers, the Ah figure can be the C20 or the C5 figure, so it's important to know which one. Some, like Varta, will give you both figures. The C20 and C5 figures are sometimes called the '20-hour rate' and the '5-hour rate'.

Other figures like the CCA (Cold Cranking Amps) are relevant if used as a starter battery, but not important for a leisure battery.

 

[VXman]

Thanks for all the response so far - very informative and useful.

Could someone clarify - what thickness/spec cable would be sensible for adding a 2nd battery say a metre away from the first. 16mm?

I assume this would be more than sufficent? https://www.ebay.co.uk/itm/25254133...d=link&campid=5338547443&toolid=20001&mkevt=1

 

[Blue Knight]

There's not a lot of room and certainly one identical to the original will not fit.

Do you have a Fiat X290 chassis and are you certain they won't fit.

I do know people who have fitted 2 x LA95 AGMs under their drivers seat.

It doesn't often look possible but others have done so.

Here's a pic of my 2 x L36 EFBs (same dimensions as your AGM) under my passenger seat.

It looks tight, it is tight... but it works fine.

All the best,

Andrew

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[autorouter]

The starting point would be the existing cables. Anything thicker than that would be a bonus. If you can't guess the cross-sectional area, it's usually stamped on the outside of the cable sheath at regular intervals. Shining a torch at a shallow angle shows it up better.

For fuses, consider using Midi fuseholders and fuses. They bolt onto eyelet crimp terminals usually found on battery cables. The minimum value is 30A, which you might think is too high, but if it isn't they are good.

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Shop for MIDI fuses online at Altec Automotive. We stock 30-150amp MIDI fuses & their corresponding fuse holder. Prices start from as little as £1.20.

www.altecautomotive.co.uk

 

[VXman]

Do you have a Fiat X290 chassis and are you certain they won't fit.

I do know people who have fitted 2 x LA95 AGMs under their drivers seat.

It doesn't often look possible but others have done so.

Here's a pic of my 2 x L36 EFBs (same dimensions as your AGM) under my passenger seat.

It looks tight, it is tight... but it works fine.

All the best,

Andrew

View attachment 510012

No idea what Chassis I have . Fiat yes. Bog standard 2020 model I think. Looks very similar to yours.

The problem is the two areas marked where there is some plates welded to the frame where it bolts to the floor. It narrows the width by about 6 cm. Of course I'd need to relocate the fuse assembly.

However I was intending keeping the retaining bar which would then be inside the two batteries. Yours look almost flush. Don't you have a retaining bar in between? If not how are they secured? Also my battery seems to be slightly wider at the base (has a lip) so wouldn't be as flush at the top as yours look? Could be the pic is deceptive though.

 

[Jamesh]

Thanks for all the response so far - very informative and useful.

Could someone clarify - what thickness/spec cable would be sensible for adding a 2nd battery say a metre away from the first. 16mm?

I assume this would be more than sufficent? https://www.ebay.co.uk/itm/25254133...d=link&campid=5338547443&toolid=20001&mkevt=1

I don't think you need such big cables if the two batteries are permenantly joined?

Only enough for to cope with the biggest load you will impose on the battery.

Big cables are needed where you have a crude vsr which transfers current from engine battery to a discharged habitation battery when the engine is running.

Cheers James

 

[VXman]

Do you have a Fiat X290 chassis and are you certain they won't fit.

I do know people who have fitted 2 x LA95 AGMs under their drivers seat.

It doesn't often look possible but others have done so.

Here's a pic of my 2 x L36 EFBs (same dimensions as your AGM) under my passenger seat.

It looks tight, it is tight... but it works fine.

All the best,

Andrew

Just checked again - it's tight without the bar. Very tight. You battery seems to be shorter than mine at 335 v 353. That too could make a difference. The only way to be sure would be to buy one, try it for fit and return if it didn't (if the vendor allowed.)

Did you remove the bottom part of the seat frame (the section that bolts to the chassis) to re-route the cables etc underneath the base plate that is holding the battery?

 

[VXman]

I don't think you need such big cables if the two batteries are permenantly joined?

Only enough for to cope with the biggest load you will impose on the battery.

Big cables are needed where you have a crude vsr which transfers current from engine battery to a discharged habitation battery when the engine is running.

Cheers James

Even when running a longer distance between batteries - like I said -probably just over a metre?

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[pappajohn]

Even when running a longer distance between batteries - like I said -probably just over a metre?

Thin cable + long distance = volt drop.
If you go for 16mmsq cable it should cover most instances unless you have an inverter..... Then you're looking at 50mmsq plus depending on the inverter output.
Cable can never be too big.

 

[Blue Knight]

Just checked again - it's tight without the bar. Very tight. You battery seems to be shorter than mine at 335 v 353. That too could make a difference. The only way to be sure would be to buy one, try it for fit and return if it didn't (if the vendor allowed.)

Did you remove the bottom part of the seat frame (the section that bolts to the chassis) to re-route the cables etc underneath the base plate that is holding the battery?

Both batteries (L36 EFB and the LA95) have the same dimensions; i.e. 353(L) x 175(W) x 190(H).

Here's a pic of my newly supplied LA95 AGM before I swapped it out for 2 x L36 batteries. I relocated the LA95 to the rear of the van to help run our telly and other 12v supplies and lights etc.

That said, the second pic below shows my factory supplied battery mount which came with the van.

 

[VXman]

Both batteries (L36 EFB and the LA95) have the same dimensions; i.e. 353(L) x 175(W) x 190(H).

Here's a pic of my newly supplied LA95 AGM before I swapped it out for 2 x L36 batteries. I relocated the LA95 to the rear of the van to help run our telly and other 12v supplies and lights etc.

That said, the second pic below shows my factory supplied battery mount which came with the van.

View attachment 510058
View attachment 510059

Hmm- looks a little different at the front on the frame. Interestingly yours is under the passenger seat. Mines the drivers side. Is there something securing your batteries to the floor in between them?