Old Crow
Searching....
Well, I didn't know whether to add this one to the 'Stupid Things You've Done' thread or start a new one. In any case, I know a number of WTW members have Noco G7200 battery chargers so I thought I'd post this info...
A few days ago I was checking on my vehicle batteries and noticed the LED on the solar battery maintainer wired to my ATV's battery didn't look right. It's normally yellow or green but this time appeared to be off or very, very faint... it was tough to tell in the bright sunlight.
I put a multimeter across the battery terminals and at first thought my meter must be bad. It was showing 27 millivolts (!!!). I was mystified as I had recently started up and moved the ATV. But when I turned the key I realized Mr. Easily-Distracted (me) had left it on after that move a few weeks ago. So apparently the solar maintainer panel couldn't keep up with the ATV's rate of discharge (when the key is left on).
I recently bought yet another battery charger and thought I'd give it a try. After a few minutes it lit the bad-battery-I'm-done indication. I also tried my G7200 charger and it did the same. I considered putting my old-school 1980s Exide charger on to get voltage up enough to fool a modern charger into working on it but at that point it occurred to me the battery might be frozen so I pulled it and took it inside.
The next day I was happy to find the battery had spontaneously recovered itself to 3+ volts. That should be enough for a modern charger to not declare it a bad battery so I put the G7200 and a voltage logger on it.
And here's the reason for this post--- the interesting plot of the G7200 running its charging program on the dead battery..
(Click to enlarge)
After starting the charger I put the multimeter on and saw voltage changing about every second. And as I watched I saw it charge at voltages in the 12s for a bit, then in single-digit voltages for a bit. And when it switched between those ranges, I'd hear a click in the charger.
The graphed data can also be viewed as a text file and perhaps it gives a better idea of what the charger was doing.... (this is only the first two of 258 pages of data).
(Note- the zero voltages at the beginning were recorded before I connected the logger to the battery)
I don't know for sure how the battery has come out of this for the longer term. Resting voltage looked great (12.7-ish) but then it barely passed a load test. And according to my digital tester, internal resistance is high. It's a six-year-old battery so perhaps that's not surprising.
I put the battery back in the ATV and was able to start it. That one doesn't start easily so it put a pretty good cranking load on the battery. I was surprised how well it did. Still, I wouldn't want to trust it away from home given the borderline load test and its high internal resistance.
.
A few days ago I was checking on my vehicle batteries and noticed the LED on the solar battery maintainer wired to my ATV's battery didn't look right. It's normally yellow or green but this time appeared to be off or very, very faint... it was tough to tell in the bright sunlight.
I put a multimeter across the battery terminals and at first thought my meter must be bad. It was showing 27 millivolts (!!!). I was mystified as I had recently started up and moved the ATV. But when I turned the key I realized Mr. Easily-Distracted (me) had left it on after that move a few weeks ago. So apparently the solar maintainer panel couldn't keep up with the ATV's rate of discharge (when the key is left on).
I recently bought yet another battery charger and thought I'd give it a try. After a few minutes it lit the bad-battery-I'm-done indication. I also tried my G7200 charger and it did the same. I considered putting my old-school 1980s Exide charger on to get voltage up enough to fool a modern charger into working on it but at that point it occurred to me the battery might be frozen so I pulled it and took it inside.
The next day I was happy to find the battery had spontaneously recovered itself to 3+ volts. That should be enough for a modern charger to not declare it a bad battery so I put the G7200 and a voltage logger on it.
And here's the reason for this post--- the interesting plot of the G7200 running its charging program on the dead battery..
(Click to enlarge)
After starting the charger I put the multimeter on and saw voltage changing about every second. And as I watched I saw it charge at voltages in the 12s for a bit, then in single-digit voltages for a bit. And when it switched between those ranges, I'd hear a click in the charger.
The graphed data can also be viewed as a text file and perhaps it gives a better idea of what the charger was doing.... (this is only the first two of 258 pages of data).
(Note- the zero voltages at the beginning were recorded before I connected the logger to the battery)
I don't know for sure how the battery has come out of this for the longer term. Resting voltage looked great (12.7-ish) but then it barely passed a load test. And according to my digital tester, internal resistance is high. It's a six-year-old battery so perhaps that's not surprising.
I put the battery back in the ATV and was able to start it. That one doesn't start easily so it put a pretty good cranking load on the battery. I was surprised how well it did. Still, I wouldn't want to trust it away from home given the borderline load test and its high internal resistance.
.