ISO Lithium battery to fit in Rubicon rear storage cubby

[Pgopinath]

Hello.

New member here. I recently picked up a used ER XV-JP and am hoping to reconfigure the battery setup. Current setup is two Lifeline AGMs for a total of 12V 210AH. These are mounted beneath the vehicle streetside. I would like to get close to equivalent capacity in a lithium battery bank fit into the underfloor storage cubby at the back.

I have searched every possible vendor and forum and havent found anything that would fit.

Does anyone know of someone that could build me a pack using 18650 cells or other tech?

Appreciate any pointers.

Thanks
Prabha

 

[plh]

Too much liability for somebody to build you a 18650 pack. You could build it yourself however.

 

[hour]

Look up ebike DIY batteries on youtube. They usually go from 36v -> 72v but you can get the idea. I think it's maker kits or some term like that which makes snap on terminal ends so you can easily build yourself batteries without soldering, spot welding, etc.

 

[Pgopinath]

I think i have made some progress in my quest. I could use a sanity check though.

First some background. My Earthroamer Rubicon has two AGM house batteries (12V 210AH total) mounted under the vehicle streetside protected by a heavy duty skid plate. The vehicle has a 5.7L hemi and fuel consumption is pretty robust. I am not complaining because the bigger engine makes the ER functional and I can drive on I-70 through the mountain passes without slowing down other traffic. I would like to install a Longrange Automotive aux fuel tank which gives me an additional 16Gal of fuel to augment the factory 20gal tank. This aux tank is designed to install exactly where the house batteries are currently installed.

I first thought that I could have a fab shop cut out the existing rear under floor cubby, build a larger box, and move the AGM batteries there. The shop wanted almost $5000 for that work. That's crazy for 16 additional gals of fuel so i have been looking for smaller batteries with approx the same effective capacity.

My current AGM bank gives me an effective 12V*210AH*0.5= 1.26KWH
With a LiFePO4 i can expect 80% discharge levels so a LiFePO4 bank that gives me close to 1.26KWH should be fine and may fit into the rear cubby.

I found a 3.2V 120AH online (https://www.electriccarpartscompany.com/Bright-Star-120Ah-Aluminum-Encased-Battery ) . Four of these connected in series would give me 3.2V*4*120AH*0.8 = 1.228KWH. which is slightly more than equivalent to current capacity. (IS THIS CORRECT?) So i am good on capacity. Its dimensions are 6.8"W x 6.7"H x 1.89"Thick. So a two cell series sandwich would be 3.8" thick for 6V/120AH

The built in fridge in the ER partially blocks off opening to the rear in floor cubby. The opening that is left is 9.5" (front to back) and 10.25" left to right. The overall cubby is 4.5" deep and 20.75" w (L-R).

I think i could make two 6V series sandwiches mount them in plywood boxes and slide them into the cubby through the existing opening, secure them properly, and complete the final connections in the cubby to give me a 12V/120AH bank. I would mount a couple of bulkhead battery terminals to the streetside wall of the cubby to complete the under vehicle battery connections.

What do you all think?

Thanks
Prabha