I just got this phone mount with a voltmeter for the battery.

For the electronic experts out there:
Is this thing actually useful? Does the voltmeter tell me the health of my battery?

The reason I got this is that the last holder I had that was similar, drained my battery overnight.

Thank you!


https://www.walmart.com/ip/3-in-1-Ca...ung-/106858106

 

First, your socket is going to turn off after some short period of time, when you turn off the car. You will have to turn on the ignition again to see rested battery voltage. But, if you start the car you will only see alternator voltage. This is what you will see with the car running. There are a couple of old threads discussing the strange voltage regulator behavior when monitored with a voltmeter. I am convinced that Jaguar has this set to almost never fully charge the battery. Anyhow, using this holder should not drain your battery.
Larry

 

Thank you.

Yeah, that's what I thought with the last one I tried. But even when I took it into the dealer to check, it drained my battery. I think Proclip might be the only way for me.