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

If your batteries are linked through the ML-ACR for charging while driving (as they should be) you wont need an additional monitor in by the driver's seat to monitor your second battery while driving - both will be at the alternator voltage displayed on the scangauge. However, if your scangauge is like my ultragauge, the truck has to be at least in ACC mode to give voltage readings... This is where you will really want a dual monitor wired to the batteries for when the truck is off and you are using power without the charging system on and you can keep an eye on both batteries. Your scangauge will likely not serve that function

FWIW I have 2 dual monitors in my truck. One in by the drivers side where I can look through the window to check voltages when the truck is off and one in the bed by my big draw accessories so I I can quickly check it from there.

 

Makes sense. Thank you for the info. I will have a readout for the second battery in the bed. While driving, they should be linked so that makes perfect sense.

I may just buy those cheap digital display and make some holes in the centre console. Wire them to a switch so I can turn them off when the trucks off and be done with it. Can monitor them easily that way, and won't break the bank. Those rocker switches with two digital readout are nice but $50-60 is too much for me. Just have to get creative.

 

I had my ML-ACR crap on me (for reasons unknown) and had I not installed a dual voltage gauge, I probably wouldn't have known that the 2nd battery wasn't getting a charge. I also have solar hooked up to the 2nd battery but I was camping in the winter with no sun so it barely did a thing with fridge, lights, air compressor, etc drawing from it.

btw - Blue Sea replaced the unit after all said and done.

 

The one I have in the bed is a cheap single monitor wired to an on-off-on momentary switch so that way I only needed one monitor and one switch to monitor two batteries. The other dual monitor that a lot of us use is less than $30 shipped from South Africa, so not too expensive, but it isn't as granular a readout as the digital monitors.

 

Good point. My advice was more to say that the scangauge only works with the truck on, and while driving both batteries should be at the same voltage. Were you getting any blinking lights from the ML-ACR switch?

 

Your bed set up was what I was thinking as well. As for the switch, I'm in Canada....everything is a tad more expensive between shipping and the exchange.

 

I was getting all bunch of incorrect lights from the switch - random blinking (slow, fast), no lights on when it was connected, lights on when it wasn't connected, manual on/off wasn't working. It was all bad

 

Thanks for this link. Didn't realize how small it was. Went with this for inside the cab. Will wire the monitor and a USB up to a switch so the lights/power can be shut off when not in use, or switched on when needed when the truck is off.

 

Got mine mounted this weekend. Now I need to take the time to hook them up

 

Alright the general consensus on wiring up the blue sea ml acr.

1.The isolation wires (brown, green, orange) aren't really needed?
2. for the switch, is the led on when the unit is in auto mode? My concern is always having the light on in the truck. I can wire it to ignition but if it needs power all the time then I'm stuck with the led?

 

The LED's are on whenever the batteries are linked. They will stay on with the car off, until the ML-ACR unlinks them.

 

I don't have the remote switch hooked up. You need to ground the ML-ACR with the black wire but all the other wires are optional. It will function in automatic mode and you can manually connect or isolate the batteries at the relay.

 

Very cool - anyone ever found a single or dual volt meter that fits in a contura switch cutout? (.8 x 1.4, i think...)

 

http://www.solidkit.com.au/product/dual-battery-volt-meter-toyota-120/

 

Thank you sir!

Perfect. Then just the black, yellow and red wires are getting touched. Fantastic.

Saw this one and man was it tempting, But it would have been easily over $100 Canadian to get it to canada. It's really nice though.

 

Do you disconnect or unlatch the batteries when you are using this? I'm about to pick one up.

 

Yes, I manually disconnect the batterys with the ML-ACR

 

Cool thanks!

 

Looks like this item is no longer available on eBay, or at least temporarily unavailable. Any other good options to monitor both batteries that aren't too expensive?

 

I used 3 of these (since I have 3 batteries):
http://m.ebay.com/itm/Digital-LED-V...Battery-Measure-BLUE-/290940256410?nav=SEARCH

I've had no issues. Just make sure you get the version with 3 wires so that they don't stay on constant.