ZipZap said:
...Did you get a chance to try your LiPo or non-AGM lead acid replacement yet?
"He's not dead yet!"
Awesome shop ! What's with the big pack of 18650's? Are you into Ebikes?!
Anyway, you seem to have a clamp on ammeter to come up with your numbers.
Can you make a load out of headlights, or something, and do a Capacity Check on the bench?
An auto shop only does the old school 'Cranking Amps' test. I've had a bad battery pass that test but die quickly on a 'Cap Check'. Besides, these batteries never 'Crank'.
This is what that RC number on the battery data tag means:
Reserve Capacity (RC) is a very important rating. This is the number of minutes a fully charged battery at 80°F will discharge at 25 amps until the battery drops below 10.5 volts.
This number can be converted to an Ahr number, then you can run the test at whatever load you can come up with.
The way I understand it is, the APM takes the place of the alternator. It only supplies a bus voltage and the 12 V battery just floats on this bus when the car is powered up. The voltage may vary with temp.
You can see the current transformer on the 12V battery negative lead, so it must monitor current to and from the 12V battery. Not sure how that is used in the system.
Also I think I read that the APM provides an 'anti-sulfation' mode to help with the health of the 12V battery.
This battery only boots up the car, correct? Once the car is powered on, the 12V bus is powered by the APM.
The big size is for some fed spec for keeping the flashers and headlights on for X amount of time.
Mine is hanging in there. When it finally dies I
will go for a different replacement.
Do you have a motorcycle battery sitting out the winter? I'd try that and monitor it.
Can you build a 18650 based 14 V battery pack that has a BMS that would run while the car is powered up? (I'd bring a back up...)