Aux battery under the bed

Has anyone mounted a large-ish flooded battery (group 31, 60lbs) under the bed? It's too tall to fit under my platform in the bed so trying to find an alternate mounting location. Was thinking about behind the rear bumper on the driver side. Any advice/ lessons learned would be appreciated

 

Have to think about wire size/length. You’d need huge wire if it’s gonna be that far away

 

I can't answer you question about under the bed. I did put a Group 35 in my TRD Off Road, using Off-Grid Engineering's passenger side tray. Of course you can't fit a Group 31 there, but I did read that someone switched to the starter to that passenger side location and a Group 31 for the auxiliary where the starter use to be.

 

Sorry I guess I should have mentioned that the battery is for appliances in the rear; water pump, fridge, compressor, etc. It would be cool to hook it up to the alternator for charging while driving, but I didn't see a spot in the engine bay that would accommodate such a bulky battery. So if I want to do that I figured I'd have to run a decent gauge wire from the alternator back

 

Well, like I said, you could switch wiring and put in a Group 31 and treat it as the auxiliary where the starter is. Having an Off Road yourself, that spot in the back on the passenger side is perfect for a Group 35, and yes, both charge off of the alternator.

As far as wiring I have a fridge now full time behind my front seat and run wiring to the fridge using Anderson plugs.

I'll add that I can totally see having a Group 31 for the auxiliary. I figure that a Group 35 on a hot day, no airflow into the cab, fridge runs about 30 hours (my fridge shuts off a 11.2v), and of course longer run time with cooler temps. Charge time I figure off of the alternator when at 11.2v is upwards of 45 minutes of driving. Rethinking this, I might have gone with Off-Grid's DC to DC, as the the Redarc charger that kit comes with includes a solar plug in ... would be nice to work in a panel. (I just went with the Blue Sea relay, and two Group 35s.)

 

Ah I see, I misunderstood your first post. Just to make sure I am understanding correctly, you are suggesting that I put the factory 24F(?) starting battery in the passenger side rear location and put the 31 deep cycle in the factory position?

 

Exactly. You can fit a Group 31 in the spot that the factory battery is. Then use the Group 35 for the starter. You'd just have to reroute the starter battery cables.

This is the setup I have: Here
Or the DC to DC option: Here
(edited links!)

 

Are you planning on not starting your truck for 5 days or more?

I ask because you can run a compressor, fridge etc off a single battery for a few days. Swap out the lead acid for a Group 34 AGM and you are set for several days. You could even use the money saved and upgrade to a RedArc battery charger with solar.

Doesnt answer your question about mounting the battery but I think dual batteries are sometimes over represented.

 

I'd at least go to a Group 31 if you're going to utilize your starter for other things. And carry a battery jumper.

 

If that’s what someone wants. I don’t see a reason to run a commercial battery group when normal automotive batteries work just fine.

 

Looks like links are censored by TW

I got a deal on this battery I couldn't ignore so I am railroaded on the dual battery set up even though it is obviously more space and weight. It is very rare for me to go even a day without starting the truck on a trip, as I go from spot to trailhead to spot (etc). So I figure between the two I won't have any problems with running a Dometic cfx 35W, small water pump, air compressor, LED camp lights, and a couple 12V computer fans for about 12 hrs between alternator charges.

 

The other problem with this is most (if any) deep cycle batteries would start the truck without harming them, and a starter battery is not meant for long, smaller continuous drain

 

Ugh .... offgrid4x4 (dot) com
See: 2005-Current Toyota Tacoma TRD Off-Road/ TRD Pro Complete Dual Battery System "Split-System"
And: REDARC/ OGE Complete Dual Battery System with DC to DC Charging Technology - For Toyota Trucks and SUV's