12v battery health observation

Yeah, after watching the video on comment #2 by Prof. Kelly at WSU. I now want a Fluke 87 Series V multimeter. And he has THREE of them in his arsenal. But... That's gonna cost me a lot...

 

I used the Fluke 87 in the can factory and at the radio station. Really nice meter. But probably overkill unless you're using it professionally.

When the Fluke at the radio station died, we got an Amprobe and I was just as happy with it for a considerably better price. Can't remember which model it was, but it was true RMS plus lots of other features. Might have been this one. Looks like it anyway.

At home, I'm very happy so far with my Klein CL380. It's a clamp on meter that also does DC current.

 

Come on, what exactly ??
AGM batteries in general are known to last MUCH longer than conventional wet cell ones, especially when the owner completely neglects checking the electrolyte level in the old style ones.
Twice the life is NOT out of the question.

 

Because they can save $20 per car by putting the cheaper kind.
There are NO circumstances that I am aware of where an AGM is not a better choice.

 

I bet you're jealous .

Life favors the prepared .

 

the wet cell 12v in my '05 dakota is still humming along nicely. i've never checked the water.

what a shame we have to spend so much time and money monitoring the health of the prius 12v

 

Oh, dear - I must be neglectful - mine is about to have her 4th birthday, and I've never thought about it - apart from when, a couple of years ago, I left the lights on. It wouldn't start, but I left it for a few hours and there was enough charge for it to start again.

 

'Scuse me. Gotta go make sure my lug nuts are still tight.

The only reason I've paid any particular attention to mine is as a participant in threads like this one. And maybe a little more now that I'm not driving as much, which would be the case with any car. My extra attention consists of the little voltage monitor I plugged into the 12V outlet.

 

well done, agreed. you're in good shape for awhile. i just don't think any prius will charge a battery to full in 40 miles.
8 hours is the recommended, which is at least 250- 320 miles.

but if you're driving more regularly, it doesn't drop down much.

 

idk. and it's an old suggestion for gen2, so it's probably a little different. i do know (from reading here) that all prius are designed to maintain voltage, and struggle to do more than a little charging.

 

Well you aren't really done yet.
If it stabilizes at 12.5, you're fine.
BUT if it continues to drop a tenth or more per 8 hours, then you have a problem.
That means that it will take about 3 days or less to reach 50% discharged and that is NOT fine.

 

Maybe others will know for sure but I think other things might "wake up" when the dome light is triggered.
If you were there only to measure battery voltage, why were you even inside the car ??

 

FWIW, I am taking SOC reading on my 2020 PRIME on this tread 12v Battery Is Discharging, Re-Charge Now ! | Page 4 | PriusChat. My almost brand new PRIME has sat on PARK for 5 days now since I fully charged the 12v. I have BlueTooth Battery Monitor installed, so I can remotely monitor the 12V battery SOC 24/7 without touching the car. Initially, the fully charged battery lost ~0.1v/day for the first 3 days. It changed from 13.06v to 12.64v. But on 4th day, it changed from 12.64v to 12.62v. It seems to have stabilized. My pre-full charge reading was 12.56v 91% SOC. I have a feeling that it is not going down below that mark even if I let my car sit longer than a week. I will see.