Second battery locations

N

nhurto

NAXJA Forum User
Location
VA
I'm adding a second battery to my rig and am trying to keep as much space as possible available under the hood for a York. Has anyone relocated their battery under the rear seat? If so, any lessons learned?
 
Not much room under the rear seat.

In other thoughts... The VW Beetles had the battery under the rear seat. People would forget to put the cover back over the battery. When someone would them occupy the back seat, the springs would hit the battery posts, igniting the hemp they used to stuff the seats with. less than 5min later, no more Beetle.

Unfortunately, it was just plain 'ol hemp, so no Hippies got high in the process ;)

-Ron
 
WB9YZU said:
Not much room under the rear seat.

In other thoughts... The VW Beetles had the battery under the rear seat. People would forget to put the cover back over the battery. When someone would them occupy the back seat, the springs would hit the battery posts, igniting the hemp they used to stuff the seats with. less than 5min later, no more Beetle.

Unfortunately, it was just plain 'ol hemp, so no Hippies got high in the process ;)

-Ron
Click to expand...

Plan to cut out the floor and build a battery compartment for a sealed plastic battery box to fit in.
 
I'm not sure if I'm adding to anything you already know, but I've just planned out my dual battery setup. I'm doing the cowl intake mod and then putting a battery where the air-box used to be.

I've been following the advice of a write-up I found. In it, the guy recommends NOT to install a battery inside your vehicle with the caveat that an AGM battery might be OK.

The relevant text from link above:

Battery placement.

A very important thing to consider is where you are going to place your batteries, standard open wet cell batteries give off hydrogen gas when they are charging and discharging, this is a very explosive gas, remember the Hindenburg, there is no problem if you are putting the auxiliary battery under the bonnet of your vehicle, or mounting it somewhere on the chassis with good ventilation to the open air.

Just throwing them under a seat or in a cupboard is far from ideal and just down right dangerous, even worse some people place battery chargers and even inverters next to these batteries, just think about that for a moment, a hydrogen producing device next to a possible spark producing device, I guess some people just don't know or don’t think!

Wet cell batteries must be housed in a properly vented area, and must be well vented externally away from any ignition source and from human habitat areas, hydrogen gas rises so sealed battery enclosures should be vented externally top and bottom.

If you need to place batteries inside vehicles, then AGM batteries should be seriously considered here as they are totally sealed, AGM batteries if placed in an enclosure only need to be vented to atmosphere not necessarily vented externally.

Putting AGM batteries under the car bonnet is fine as far as safety goes, the only consideration here is that AGM’s and any fully sealed batteries should be kept away from the extreme temperatures of turbochargers, and if they must be placed close to the turbocharger, then heat shields should be used.
Click to expand...

This is where I'm at with my cowl intake:

20140306091804-60c2ad39-284f2b_870x870.jpg
 
People have built ventilated battery boxes for the interior that vent to the atmosphere. I'm glad this thread was started. I like the under rear seat storage with a cutout to drop it down. I'm wanting to do the 5.3L swap similar to Jeremy B, because it is the cleanest one Ive seen. One reason is because he moved the battery to the cargo area to clean up and simplify the engine bay. But I need liked the idea of the exposed (even in a batt box) battery and loss of cargo space. Sinking it under the seat would avoid that, and I think there is room under the floor there for the extra volume.

Someone on hear had dual group 31s in the rear cubby area. Don't know how that worked out. I know when tubbing my rear fenders I was amazed at how much the floor in that area flexed.
 
You can put an AGM on it's side above either rear wheel well. You need to cut the sheetmetal some, but you can fit a large one there. Guy on Pirate did it but the pics are broken now... (Everything I've read indicates that AGM batteries do not need to be vented...)
 
FWIW - Volvo mounts their batteries in the trunk next to the spare tire. A 1/8" vent tube to a bulkhead fitting that goes to atmosphere is all they bother with.
Also - hydrogen gasing is the result of over-charger or crazy-high-discharge. In normal function, it should be fine.
The vent is still worth adding.
 
If the reason you are fitting two batteries is because you are worried that an electric winch may leave you with a flat battery unable to start the engine, here's an alternative that you may wish to consider..

Use an Odyssey battery that's about one third the size of the winch battery as a secondary starting battery. You can use a regular low amp split charge system to keep it topped up. You may even be able to get both batteries snuggled together in the same box or find a suitable hiding place for the small battery like under a front fender or inside a winch bumper. To use it either connect booster cables between the two batteries or have the terminals permanently connected with an isolation switch in the positive cable.

A small Odyssey battery may have enough power for 2 or more starts but if you have an Odyssey main battery it should recover within about 20 minutes of alternator charging to return to normal duty.

I haven't tried this method myself, but I have used a portable booster pack to start my Jeep when it's Odyssey PC1200 was flat and it worked well. Portable jump starters usually have something like an 18Ah 360CCA 12V battery inside.

I have owned cars before that have had OEM trunk mounted batteries before (old Minis and Jaguars). The long 'unfused' positive lead is a vulnerability that could cause a massive spark or short circuit overload if it got damaged.
 
Hellbent said:
Worth mentioning, I think....

I have one of those, and it's amazing. Worth ever penny, IMO.
Click to expand...

does it actually manage to turn over a 4.0 with no assistance(battery disconnected)? if so that is certainly impressive.

i still wouldnt consider that a replacement for a second battery, but certainly worth carrying along for emergencies.
 
yep, without issue.
i used it about a week and a half ago on a JK with a DEAD battery. no interior lights, no dash lights, no click.....nothing.
it had been sitting in my truck for at least a month untouched. pulled it out, hooked it up to the JK, turned the key, fired right up immediately.


biztyke said:
does it actually manage to turn over a 4.0 with no assistance(battery disconnected)? if so that is certainly impressive.

i still wouldnt consider that a replacement for a second battery, but certainly worth carrying along for emergencies.
Click to expand...
 
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