How to make a cheap isolated dual-battery setup for $50

[dlichterman]

Yes, they are for cranking power. So how would one wire in a third battery to charge off of the stock alternator, yet be isolated? I should probably run a larger alternator. Also should I run a solar panel in conjunction with all of this? Or would that be overkill?

Assuming it is a 12V system you would just need to attach wires from one of the batteries to the 3rd isolated battery. Best to find where the alternator hooks up and attach there I would think. Do your trips commonly involve parking the truck for a few days? That's why I added solar to my truck to run the fridge.

 

[bigoldford]

Assuming it is a 12V system you would just need to attach wires from one of the batteries to the 3rd isolated battery. Best to find where the alternator hooks up and attach there I would think. Do your trips commonly involve parking the truck for a few days? That's why I added solar to my truck to run the fridge.

Just to be clear, I would wire the house battery in just like the original diagram? Ignoring the stock second battery?

Yea I would be without power for several days at a time, the plan is to get a fridge at some point, my fiancée has medication we have to keep refrigerated.

 

[dlichterman]

Just to be clear, I would wire the house battery in just like the original diagram? Ignoring the stock second battery?

Yea I would be without power for several days at a time, the plan is to get a fridge at some point, my fiancée has medication we have to keep refrigerated.

Yep, as long as you can tie in to somewhere that the alternator is feeding, you should be good. Can't recommend getting a 12V fridge enough - it is really nice to not need to worry about ice.

 

[mtaylor]

I set up duals in my truck following this guide (mostly, I can't help but freestyle a bit) and it's working great. Thanks for the inspiration!

 

[silkroad]

I'm sure the answer is in here somewhere but with 67 pages I'll be drunk by the time I find it...

Any issues with grounding the house battery to the body instead of connecting to the starting battery? I'm pretty much referring to the very first diagram.

 

[DiploStrat]

...
Any issues with grounding the house battery to the body instead of connecting to the starting battery?

You REALLY need to read the whole thread.

That said - Don't use the body for the ground return, too many chances of a bad connection somewhere.

Scholars differ on the rest. I use the same frame rail to ground my camper/house batteries as the factory uses for the starter battery. Some would insist on running a separate ground return back to the starter battery.

 

[fiddypal]

I was told from some car audio gurus that on my truck in particular(14' silverado), I had to tie my 2nd battery ground to the starting battery or the truck would not 'sense' the other battery and would lead to charging issues. I took their word for it and ran a dedicated ground line and have not had any issues to date. That 0 gauge cable is not cheap tho! Make sure you order exactly what you need.

 

[silkroad]

The first setup on my subaru was done by an Audio shop and they grounded to the body; used to run 12v fridge and some usb charging with no issues. I'm doing a reinstall on my new rig so will ground to the starting battery to firm things up and avoid any possible problems.

Now thanks to Dave every time I see a AA battery or walk into a shade(also making his on the cheap awning) I crave a beer. Cheers both.

 

[IdaSHO]

Those are pretty slick!

I especially like the dual-bank voltage meters.

Thanks for posting them up! :ylsmoke:

 

[patoz]

I'll leave this here---

DUAL BATTERY MONITOR SWITCH BLANK

http://www.solidkit.com.au


Get them on EBAY and save on the conversion rate from AU to your respective currency. Shipping is free too.

I tried to find them on eBay, but no luck. Do I need to look on the Australian eBay site specifically for them?

 

[inv3ctiv3]

I just did this in my tacoma with the aux deep cycle battery in the bed locked in a pelican case with my air compressor:

I didn't have time to mount the blue sea fuse box or wire up all my accessories but I'll do that this week.

 

[patoz]

I just did this in my tacoma with the aux deep cycle battery in the bed locked in a pelican case with my air compressor:

I didn't have time to mount the blue sea fuse box or wire up all my accessories but I'll do that this week.

Your pictures didn't show up!

 

[inv3ctiv3]

Your pictures didn't show up!

Whoops!

Dual batteries are in by Jim Bob Barnett, on Flickr

Dual batteries are in by Jim Bob Barnett, on Flickr

Ignore the tie downs it's being bolted into the bed once I mount the compressor:

Dual batteries are in by Jim Bob Barnett, on Flickr

Dual batteries are in by Jim Bob Barnett, on Flickr

 

[patoz]

http://www.ebay.com/itm/Dual-Batter...-Carling-Rocker-Size-AGM-Marine-/222212932669

http://www.ebay.com/usr/solid_kit_au

search criteria was 'Dual Battery Volt Meter Gauge Contour'

Got it, thanks for the help!

 

[RememberTheFallen]

About to leave to go camping off the grid for several days and realized that my battery is not charging when the engine is running. I have noticed that battery voltage has been lower than usual the last couple weeks but paid no attention as I have not been driving very far. Checked it out and found that voltage is staying the same when engine is off and running, it used to spike to 13.7v but just stays at 12.0v now. Any ideas what to check?

I have the same setup used here. My 12v ignition on runs to a piggyback in fuse block. Fuses are good. My 100a fuses appear to be good also. All bolts and fittings are tight. I have a multimeter and tried checking with it but honestly it has so many features that it confuses me.

Any help would be greatly appreciated!!!


EDIT: Jumped the isolater by putting the two hot wires together. No change in voltage read out with engine running or off. So it is safe to assume it is an issue between the isolator and house battery, correct?

Joe