DIY 24V and 12V Dual Battery Voltage Monitor

[ForealBoreal]

So I am hoping to build a budget dual battery monitor without breaking the bank.
Hoping to build this whole thing for under $20 bucks to be completely honest.

I am hoping to use this little sucker. Works with 12 and 24v without an issue.
http://www.ebay.ca/itm/261137495326?_trksid=p5197.c0.m619#ht_3409wt_1220


My main idea is to be able to check both of my battery banks voltage levels, I know this can be done simply with a 3 way switch though my problem lies with having a 24v battery system and a 3rd battery strictly for 12v accessories. Anyone know a way how I could wire a 2 way switch to check both of my battery banks?

 

[Dieseler]

Are you wanting to read each battery individually.
Why not a 3 way selectable switch then you can check individually or with a 2 way wire your 24V as one read and your 3rd battery as a single read 12V.

 

[ForealBoreal]

Are you wanting to read each battery individually.
Why not a 3 way selectable switch then you can check individually or with a 2 way wire your 24V as one read and your 3rd battery as a single read 12V.

Exactly sorry. 3 way switch.

 

[Dieseler]

You would probably want to add a relay to your ignition so it only displays when your ignition is on.

 

[ForealBoreal]

I am wanting to just press the switch on and see if the truck is off, hoping to just check my battery state with the flick of a switch.
This should only draw a couple of milli amps.
I am not very experienced with wiring switches and relays but I have been told you can wire it using grounds to get the appropriate readings. Its tough finding info on this stuff...

 

[Dieseler]

Some of the Coastal Cruiser guys are pretty knowledgeable on this stuff I have seen some of their wiring schematics for electrical mods they seem to know what they are doing one of them posted a diagram for me to wire my night lights through a relay using my converter as the switching source but running 24V through to the 24V bulbs.

 

[ForealBoreal]

Some of the Coastal Cruiser guys are pretty knowledgeable on this stuff I have seen some of their wiring schematics for electrical mods they seem to know what they are doing one of them posted a diagram for me to wire my night lights through a relay using my converter as the switching source but running 24V through to the 24V bulbs.

I need to get ahold of stone as he seems to be a guru at this kind of thing.
I'm going to try and track him down here.

 

[markthemenace]

I need to get ahold of stone as he seems to be a guru at this kind of thing.
I'm going to try and track him down here.

Check out these two guy's website, lots of great info and here's a link specifically for what you intend doing. The guy has done it already. Basically, a single meter, but a toggle switch to see what each battery's at. And using the switch he specifies, NO draw at all unless you're pressing the switch, I think its a great idea!

I have one of those cheapo voltmeters too and had intended it for use for my bus's leisure battery. Just never got down to using it, so might do this mod as well, just for kicks.

What I'd like to see though is a more accurate reading of the batteries when running...if only to see how accurate the stock one is. Wanna do the same thing with my oil pressure gauge as well. Just because...

 

[ForealBoreal]

From Stone himself

Here's my thoughts in addition to what's been discussed on your thread.

Your 3-way switch sounds about right. So the ground would be common, but each terminal of that switch would be connected to the + terminal of each battery, and sensed by the + lead of your meter.

Flipping the switch should give you readings of each battery.

I agree that you should either run it off of a lead that's hot only when ACC or the IGN is on. You could connect a relay if you really felt like it. I try to minimize relays as much as possible if I can help it...Cruisers should be as simple and reliable as possible, right?

In order for you to be able to push a button and take a reading even if there is no key in the ignition, you would need to connect a push button switch to a constant source, and connect if to the lead that's getting the power from the ACC or IGN switched source (or relay output). Depending on how you wire this up, you may want to install a diode just so you make sure there is no backflow of current that might cause things to go funny in your vehicle. They're simple to install, and are inexpensive to purchase from places like the Source.

It doesn't matter with the switch...it's just a mechanical connection and it will be rated to a high amount of maximum voltage and amperage if you use a fairly HD one.

I'll report back on if I get this going here. This all started with me wanting to make a little mounting plate.

 

[Clint79]

I piggy backed mine off the cigi lighter ,you could do the same with that for your 24v as this only comes on with acc or when the vehicles running and use the 24v cig lighter as a trigger switch for for a relay to your 12v one so that's not on 24/7 either.

 

[ForealBoreal]

I think I just run it ign trigger.

I have rewired my 24v cig plug to 12v and I could use the leads right there to monitor both battery banks.
Perfect.
Now I gotta find a nice little contoura switch and get a nice little arb like rocker for it and make a nice little bracket.
Honestly would be checking it every so often. I am only really concerned at this point of the 3rd battery as it will be having draws when the truck is off. But it would be nice for piece of mind to check the starting batteries every once and awhile.