4 aux batteries - looking for location

Hi, I am looking for ideas of where to mount 4 "house / auxiliary" batteries.

Probably will use size 24 AGMs.

Yes, really need 4 of them, not 2 larger ones.

They don't have to be next to each other but of course that is handy.

It would be nice if they were all in a location where they were exposed to roughly the same temperature conditions so that they charge properly.

Wondering if anyone has had success mounting batteries directly to the frame underneath?

The purpose is to largely duplicate the power system in my van, except will switch to a smaller battery like the 24s in an attempt at shoe horning it all in.

Thanks

Harry

 

Unless someone has a better idea, the only thing I can think of is to put them in a really solid steel frame mount in the bed. My pick would be as far forward as you can get them (right up against the cab) so you don't have a bunch of 40-50 lb missiles trying to kill you with a front-ender.

I guess you might also be able to do a rear-seat delete and put 2 in each footwell, but I sure as shit wouldn't want those in the cab with me. Other (maybe) option would be to relocate your under bed spare, but I'd be surprised if you got more than 2 in a custom built mount there.

 

Thanks

The truck isn't used in off - road conditions -really just on-road trips to Tahoe and similar.

The rear seats are needed, but the foot well area is a possibility.

In vans, aux batteries are commonly mounted inside. You are right about the need to mount them carefully.

 

A few months ago I put one group 35 under the hood, and that was a tight fit. I'd agree, along the front of the bed in a box bolted to the bed. Line them up side by side. I would stay out of the cab myself.

 

Ditto. It's about as much aux battery as I could squeeze in.

 

So any chance of mounting them under the bed?

 

A tray, mounted under the bed somewhere? Mounted to the frame?

 

How about a large capacitor instead? I’ve seen people use them instead because they’re much smaller but can hold more energy. Only down side is you have to keep them charged which shouldn’t be a problem if you drive your truck regularly

 

Yes - that is what I am hoping to find. Ideally an example of someone having done this before or a commercial mounting system that I can just buy. Either is great.

 

I can't imagine it being too difficult to build yourself. Afaik, you'd be the first person I've seen do it. Unless some 2 genners have done it.

 

Can you think of any examples of people mounting other heavy items under the bed that I can look at to avoid re-inventing the wheel?

 

Honestly, I can't. But a search in the second gen area *might* be helpful.

 

That is not a terrible idea at all.

I have significant experience with AGMs and LiFe batteries, solar charging, etc.

The nice thing about caps is that the large temperature range, especially down into the lower range.

AGMs I can use down to ~ (-20 F)

LiFe are really only useful down to ~ + 30 F so not that great for winter use.

I am attempting to keep this project down to a "mechanical installation" project vs "both mechanical and electrical engineering" required. At this time, I don't have the resources to re-design the electrical aspects of the chargers to match the needs of the caps - but might be interesting long term.

 

Maybe the spare tire location?

 

I've seen some people mount an air compressor where the spare tire is. I'm sure you could adjust and mount batteries as needed.

Just for curiosity, why 4 batteries ?

 

LB or SB?

If you have a remote-mounted spare tire, plenty of room under the bed.

Battle born is selling the LiPo with heaters! Ideal for below 35C to allow charging not freezing weather.
https://battlebornbatteries.com/product/heated-100ah-12v-battery/

What about using 8D batteries?
https://www.trojanbattery.com/motiveagm/
161 pounds each 230 Amp Hours (20-hour rate).

My biggest question, how long off-grid, and what the heck are you powering? Inductive stovetop? Air Conditioner?

I went from my High Roof Extended Ford T250 to the Tacoma. Ford had about 5,000-pound cargo capacity, a far cry above my 950 pounds in the Tacoma. Hence for me is one 24 LiPo for cooler and CPAP.

 

For what it’s worth, I’ve seen somebody on TW replace the OEM battery with a capacitor

 

Bed.

 

Thanks - Replacing the typical starter battery with a cap style is actually relatively easy. Several companies have invested a lot of money into making that concept work. I will look at those offerings as well, but the last time I looked at the charge / discharge profiles it was not as easy of a replacement as I thought.

Still need to find a mechanical home for it either way, still roughly the same volume as 4 x 24s.

 

Yup, I did. Have capacitor under hood and small lifepo4 under back seat. Been through a few interations but working perfectly. Should last forever.

And to the one who said caps store more energy than a battery. That is wrong. They hold way less than a batt. But the cap can release it all at once if you're not careful. Like 10000 amps.

As for the original question. You can fit 4 or 8; 100 amp hr lifepo4 square cells behind back seats. But like you said, charging below freezing is a no no, so have to account for that.