Dual Battery Setups! Let's see them! Multiple Batteries Thread!

From the alt? Don't you mean the power wire from a distribution block (or the battery) going to the camper's battery?

Wire size is dependent of the length of the run and the amp load it will be asked to carry.

 

What’s the max current rating on your 7-pin connector?
You’ll need battery isolation and a charge controller to limit the current on that wire.
Choose a controller that matches your house battery.
Once you know the output of the charge controller you can size the wire and fuse it appropriately.
7-pin max current = wire rating > fuse rating > controller output.
Slow recharge is always better than fast so even if the connector and wire is up to the unlimited alternator output that output should be reduced to the optimum charge current for your house battery.
If the controller output and optimum charge current still exceeds the 7-pin max current (possible in certain circumstances) you’ll need a separate connector dedicated to that wire.
Allow time for knowledge to sink in so you really understand it and what it means. DIY means it’s on you to comprendez.

 

Wellllllll….

I gave up on my quest for doubling the house battery capacity because of space limitations and budget (not redoing the whole system to support LiFePO4).

I just doubled my solar charging input instead.

I added two portable 100w panels to my existing 175w panel.

The current house battery has a 50A capacity, which I never use more than 30A of in a day.

Adding the 2 additional portable panels essentially triples my solar output now. I should be able to keep up with usage now even on overcast days.

I did a quick test in ideal sunny and was amazed how much more power a tilted solar panel makes vs a panel mounted flat.



175w flat panel -



175w flat panel + two 100w portable panels -



On a rainy day, my flat panel still produces about 1A of power, so essentially all three panels together should make about 3A which should be enough to keep my battery mostly charged.

 

Not sure if I shared my updated dual battery and battery relocation. Went from this https://www.tacomaworld.com/threads...atteries-thread.295653/page-136#post-23309584

This setup adds a bit more flexibility since I can remove my cap without having to remove all the electronics. Gives me a bit more flexibility.

Appreciate the help that I got in this thread!

I made this panel to mount into the stock battery location. Holds the new terminal posts, aux fuse block and breaker, relays, and the blue sea ml-acr.




I tapped all the holes in case something needed to be removed. Used 1/4” aluminum plate so there was enough meat for the fastener.

I ran 2/0 for the starting battery, and 1/0 for the aux fuse panel. The batteries are located in a tool box that I modified.






and the batteries in the box


Not shown is the 400amp anl fuse for the house battery, and a 100amp breaker for the 1/0 aux line.

the aux 1/0 line has a breaker on each end to make cutoff easier when messing with the fuse panel. The 2/0 line is only fused at the battery. It’s a big amp ratting since the winch is run off of that line. The fuse also has its own fuse too.

 

This barely fit with a little trimming. The seat just barely touches it. I’ll try to get a picture of it in the truck when I get all the wires cleaned up for good. Just finished it yesterday

 

Thoughts on where to ground a battery stored in the bed? The rear factory ground on the frame (drivers side above rear wheel) looks like it has some kind of liquid rubber coating over the bolt, not sure I want to mess with it.

 

I grounded mine to one of my slider bolts to the frame. I cleaned off some paint, to have a clean electrical contact.

You can find any hole in the frame, and do the same.

Has worked fine for years.

 

Anyone experience a bit of volatge loss in the cold winter months with their AGM? Had some hard starts this winter until I got my battery warrantied. Should I be putting some insulation mat around the battery this next winter?

 

Normal depending no how cold it got. Some cars optionally come with a winter kit thats a plug in heater for the oil and battery, you can add one fairly easily.

 

Thanks, it's always good to start with what works, your build is inspirational. I'm going with CTEK and AGM also. Looks like footman loops and washers provide a viable long term strap down for 60lbs batteries?

I found I had to do quite a bit of sanding on the bed bolts before I could find continuity with ground (without removing the bolt).

Leaning towards running ~4' 2 AWG ground from under the drivers seat (or the "BD" factory ground if I can find it) to the truck bed (with a distribution block in the middle for 8awg amp(s?) and future cab accessories grounds). There's a grommet on the backside of the cab inches from the bed and I figure an interior ground maybe easier then a shorter ground to the exterior frame.

 

It certainly helped me out to have a dedicated ground buss in the cab to go with a local auxiliary fuse panel. That meant just 2 wires to the engine bay for all the in-cab accessories and no paint scraping. In CA I’m less concerned about rust than having a reliable ground for everything I add.

 

Footman loops should be strong enough. Keep an eye on your strap, as it may weaken/wear/(corrode in the old days) over time.

Have you considered battery cages, like I used? Very strong, and you should be able to find one for almost any battery.

 

sweet! that's three group 35's?

 

Yes

 

But why . . .

 

What . . .

 

why not?

 

Why three batteries instead of 2 larger ones?