Monitoring the condition of two batteries

[popotla]

I have starter battery and two more batteries in parallel, with isolator switch between starter and aux. #1 and also between aux. #1 and aux. #2. Is it possible to rig up a permanent device to continuously monitor the voltage of aux. battery #1 and aux. battery #2, and also the amps being drawn from each?

[steveG]

A voltmeter for each aux battery is easy. If all batteries are connected (ie not isolated), then the voltmeters will show the same voltage though. To me, the only real value is being able to see the voltage of each when they are isolated.

In regards to current monitoring, as long as you can get the measuring device (current shunt etc) between the terminal of each aux battery and the load so that ALL current to/from that battery goes through it then it should work fine. If you've got other connections directly to that battery terminal it won't measure the current in them.

Something like a couple of these would do what you want:

DC 120V 200A Volt AMP Combo Meter Battery Charge Discharge Indicator With Shunt | eBay