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leeds

Member Since: 28 Dec 2009
Location: West Yorkshire
Posts: 8580

Nostromo found this LINK

That article is suggesting a 0.5 volt drop on the bridging cable!

However that is for a caravan set up.

If Nostromo wants a battery for winching and assuming it is only for the occasional self recovery and not for winch challenge events couple with the fact that he does not want to go down split charge system then I would question the need for two batteries.

For self recovery where time is not of the essence.

Double line reduces the current draw and halves the effective line speed.

Winch for 1 minute, rev engine for 5 minutes to put some current back into battery.

Or buy a bigger capacity battery

The other alternative is a decent split charge system such as the IBS.

Brendan

25th Jan 2016 3:23pm

Cupboard

Member Since: 21 Mar 2014
Location: Suffolk
Posts: 2971

2011 Defender 110 Puma 2.4 HT Corris Grey

A single, large battery is always the nicest way of doing it

Quite how large a battery you can fit in the box I don't know.

25th Jan 2016 5:31pm

Nostromo

Member Since: 17 Jul 2015
Location: The Mendip Hills
Posts: 73

Many thanks for all the views and advice coming across here.

Having used my Warn winch various times now (most recently to drag a poorly positioned building skip into a space where a lorry could collect it) I’ve noticed that with my Defender battery (550Amps / 70Ah and in good nearly new condition) it doesn’t take long (about 45 seconds) until you can see and hear the battery starting to loose its sparkle – so I thought it would be a very good idea to “beef up” the reserve of 12v power to the winch – and it seemed like doubling up on the batteries would be exactly how to achieve that ?

I think I’m in this “all or nothing” situation – I just want my battery reserve to last longer when I’m using the winch, so, I can’t think that the complicated split battery arrangements that I’ve heard about and that can provide totally independent supplies for different purposes is what I’m trying to achieve. As has been said above, I’d agree I’m just trying to create a “bigger battery” and thought wiring two in parallel (within the space available under the passenger seat) would be bound to give me more power than just buying the biggest single battery that would fit under the seat ?

So I think I’ll start by taking some exact dimensional measurements of my battery compartment under the seat, see what batteries will fit under there, then establish which actually does, in theory at least, offer the most power – one big battery or two smaller ones in parallel ? . . . when I’ve got the definitive answer to that, I’ll post up my findings, and I guess that’ll be the time, if two batteries turns out to be the way to go, to worry about how to make the cables up . . . which was my original question . . and worry about the pros and cons of balancing the cycling of two batteries etc.

On this cabling point, I still can't visualise how to connect two heavy power leads off of one battery terminal post - which is what the above paralleling diagrams show - I’ve only ever seen one big power lead connected to a battery terminal . . . . so I'm still unsure about the best way to achieve that ?

Last edited by Nostromo on 26th Jan 2016 8:44am. Edited 2 times in total

25th Jan 2016 10:25pm

Mech

Member Since: 23 Oct 2013
Location: Oxfordshire
Posts: 87

I'd really recommend adding a simple switch. Although I know a lot of guys love em, I agree that relay's are a bit of over engineering. I highly recommend this one.

https://www.bluesea.com/products/9001e/e-S...ery_Switch

This allows you to manually connect battery A, battery B, battery A+B (which is the parallel arrangement you identified) or OFF.

Just this one simple addition gives you complete control over the system. If you want some added functionality, put the Anderson Connector kit from AutoSparks on the load side of the switch. It may come in handy in the future.

25th Jan 2016 11:11pm

Cupboard

Member Since: 21 Mar 2014
Location: Suffolk
Posts: 2971

Nostromo wrote:

Having used my Warn winch various times now (most recently to drag a poorly positioned building skip into a space where a lorry could collect it) I’ve noticed that with my Defender battery (550Amps / 70Ah and in good nearly new condition)

That seems very small for a Defender battery, most are a lot bigger than that... like 90Ah and 800CCA. It should be a 019 size.

Nostromo wrote:
it doesn’t take long (about 45 seconds) until you can see and hear the battery starting to loose its sparkle – so I thought it would be a very good idea to “beef up” the reserve of 12v power to the winch – and it seemed like doubling up on the batteries would be exactly how to achieve that ?

Have you got the engine running? It will work better if you have although you do need to be able to stop the Defender running away!

Nostromo wrote:

I think I’m in this “all or nothing” situation – I just want my battery reserve to last longer when I’m using the winch, so, I can’t think that the complicated split battery arrangements that I’ve heard about and that can provide totally independent supplies for different purposes is what I’m trying to achieve. As has been said above, I’d agree I’m just trying to create a “bigger battery” and thought wiring two in parallel (within the space available under the passenger seat) would be bound to give me more power than just buying the biggest single battery that would fit under the seat ?

So I think I’ll start by taking some exact dimensional measurements of my battery compartment under the seat, see what batteries will fit under there, then establish which actually does, in theory at least, offer the most power – one big battery or two smaller ones in parallel ?

Yes, one combined store is the best way of doing that, whether that's one battery or two in parallel. The energy density won't vary much, it's whatever fits in more easily. One big one is simpler to wire up but don't get too hung up on it.

Nostromo wrote:

On this cabling point, I still can't visualise how to connect two heavy power leads off of one battery terminal post - which is what the above paralleling diagrams show - I’ve only ever seen one big power lead connected to a battery terminal . . . . so I'm still unsure about the best way to achieve that ?

There are more than one sort of battery post. Some have a sort of socket with a screw in, they can only really take one. the other has an M10 post that you can put a couple of heavy cables with lugs fitted on to. If you're really pikey or in a muddle you can use a hose clamp, but that's not a good idea

26th Jan 2016 9:36am

Nostromo

Member Since: 17 Jul 2015
Location: The Mendip Hills
Posts: 73

Thanks for the above . . . makes a lot of sense.

I'll post up my analysis of what can be got under the seat in the battery space soon as I've done it . . . and check I quoted those battery ratings correctly . . . I think I did ? . . . but now you've got me wondering !

26th Jan 2016 9:28pm

leeds

Member Since: 28 Dec 2009
Location: West Yorkshire
Posts: 8580

The 8mm stud terminals are quite good and are what we use. However a bit of caution is needed as depending on the height of the batteries which are use the top of the positive stud can get very close to the negative/earth which the battery box lid is.

Be prepared to electrically insulated the underside of the battery box lid or get a piece of rubber etc to cover the top of the positive terminal.

Brendan

26th Jan 2016 11:43pm

Cupboard

Member Since: 21 Mar 2014
Location: Suffolk
Posts: 2971

That is a very important point, you really don't want it to short out on the lid because it will weld itself to the battery/batteries and you've got yourself a lovely fire underneath your passenger.

Brendan: ooi, can you put them upside down on your batteries?

27th Jan 2016 8:54am

leeds

Member Since: 28 Dec 2009
Location: West Yorkshire
Posts: 8580

Silly boy

The angle of the dangle is all wrong!

Or in this case the angle of the taper on the terminal posts. Plus the height does not change!

Brendan

27th Jan 2016 9:02am

Cupboard

Member Since: 21 Mar 2014
Location: Suffolk
Posts: 2971

of course it is, brain dead moment there!

In my defense the terminals on the little 5AH battery on my desk aren't tapered. That's a lame excuse isn't it

27th Jan 2016 1:17pm

mrd1990

Member Since: 16 Aug 2012
Location: Wales
Posts: 600

Cupboard wrote:

A single, large battery is always the nicest way of doing it
Quite how large a battery you can fit in the box I don't know.

I just fitted a 110ah Varta Battery 910CC, fits perfectly

Old vs New

Click image to enlarge

27th Jan 2016 7:07pm

Landie

Member Since: 21 Jun 2015
Location: WA
Posts: 22

2008 Defender 110 Puma 2.4 SW Zermatt Silver

Mech wrote:
I'd really recommend adding a simple switch. Although I know a lot of guys love em, I agree that relay's are a bit of over engineering. I highly recommend this one.

https://www.bluesea.com/products/9001e/e-S...ery_Switch

This allows you to manually connect battery A, battery B, battery A+B (which is the parallel arrangement you identified) or OFF.

Just this one simple addition gives you complete control over the system. If you want some added functionality, put the Anderson Connector kit from AutoSparks on the load side of the switch. It may come in handy in the future.

Also allows you to check the condition of both batteries. Used this system for years. Can also isolate (dead) battery.

Last edited by Landie on 12th Jul 2016 10:59am. Edited 1 time in total

12th Jul 2016 10:55am

Landie

Member Since: 21 Jun 2015
Location: WA
Posts: 22

Mech wrote:
I'd really recommend adding a simple switch. Although I know a lot of guys love em, I agree that relay's are a bit of over engineering. I highly recommend this one.

https://www.bluesea.com/products/9001e/e-S...ery_Switch

This allows you to manually connect battery A, battery B, battery A+B (which is the parallel arrangement you identified) or OFF.

Just this one simple addition gives you complete control over the system. If you want some added functionality, put the Anderson Connector kit from AutoSparks on the load side of the switch. It may come in handy in the future.

12th Jul 2016 10:56am

Pinky

Member Since: 09 Jun 2016
Location: England
Posts: 208

2011 Defender 110 Puma 2.4 DCPU Baltic Blue

I have enjoyed reading this thread and love all the options put forward.

I have, ( installed by the previous owner), twin batteries, one in the normal place and one in the rear tub linked in parallel. The one in the rear is connected to a 3000w inverter for tools of the trade. The only circuitry is an isolator switch under the seat but was told to leave it alone! "Fiddle at your peril". Apparently he had lots of problems switching one off.. I also seem to remember reading somewhere on this site about puma's being very sensitive to voltage changes giving rise to error codes if the correct battery isn't used.

My question is, is this true, and would any of the systems and solutions mentioned in this thread cause these error codes as I am thinking of tidying the system up and consolidating it in one place under the seat and was considering adding a switch of some sort. As its running fine at the moment if there is any chance of

it up I will leave well alone!

12th Jul 2016 7:29pm

Cold_n_Wet

Member Since: 15 Oct 2012
Location: Bergen
Posts: 244

Ive just installed a twin tay from GMB - mount, Im using twin 100 Ah batteries and an IBS split charger.

The IBS is a very smart bit of kit, thinking ahead once I add solar it will allow topping up of the main battery once the Aux is "full".

As Brendan mentioned Beat from IBS does know his stuff and has developed some very clever stuff on the charge mangement side.

The GMB mount battery tray is a nice piece of engineering, and allows good room for 2 x 100Ah batteries.

IBS recommends 25mm2 cable between batteries, but I used 35mm2 and the muti stranded welding cables for easier installation.

Im going to repeat the same installation in the 07 Puma we have, as I like it that much. "Rafiki" 2007 110 STW - Rolling rebuild.

27th Jul 2016 11:09pm

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