94 Defender Dual Battery

[GyroLandy]

Can I pelase have some views on what is the best/biggest battery that can be fitted under the passenger seat in the Defender as a 2nd battery? How many AH and dimensions would be good.

Optima, Century, CAT?

[weeds]

i believe 2 x N70 sized batteries can be shoe horned in, my batteries have always been longer so my aux is in the cargo area....

[87County]

Yep - as weeds says (2 fit under the pass seat - across)

plenty of threads on here how to do it - N70 size is a big as you need -

IMHO go for calcium (at least for No1 - ) I'm using Delkor brand in several vehicles ATM and quite satisfied

[GyroLandy]

I already have a pretty strong cranking battery and only need a 2nd battery for the fridge etc.

Are these N70 deep cycle?

[harro]

Go for an AGM if you can afford it.
A much better option for deep cycling than a flooded lead acid.

They hold their charge better.

Can handle discharging to a lower voltage.

Generally last a lot longer.

You also get more cycles for your dollar than a flooded lead acid.
I have seen some in service that are 8 plus years old and still holding around 80 percent charge.

Like everything else their are cheap versions and you get what you pay for but generally much better value as a deep cycle battery;).

They come in all shapes and sizes.
I have a 65 A/h (fell of the back of a truck:cool:) but I am sure you could get a 100 A/h in beside your start battery.

Cheers,
Paul.

[GyroLandy]

Any idea of who will supply these in Sydney area?

I read up on the differences and they mention the conventional betteries haev some sort of gas discharge hence it having to be in a ventiltaed area.

I have soundproofed and sealed by battery box under the passenger seat so now I'm concerned that my existing cranking battery which is not AGM will cause an issue. Do you need a ventilated area for batteries?

[rick130]

[snip]

Do you need a ventilated area for batteries?

Yes, that's why the battery box is ventilated ;)

Hydrogen can make a wee pop when ignited :angel:

[GyroLandy]

Thx, if for now I leave the two holes through which the battery cables run open by not inserting the grommets, will that be enough ventilation?

How much hydrogen is released, enough so that it should not be ventilated into the cabin?

I want to seal the box for deep water crossings so need to look for an alternative venting solution. Thought I's cut a meshed venting section into the box lid?

[camel_landy]

I've tried Optima and Oddessey... Frankly, I found them to be pants. I'm in the process of going back to regular type 72s.

FWIW - There is enough space to get 3x regular sized batteries in the battery box.

https://www.aulro.com/afvb/images/imported/2013/01/1498.jpg

M