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Battery charge level after running


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I have battery tenders on most of my equipment that sits during winter months. I'll still start em up and run them for 5 mins or so every month..

When I check the battery charger both batteries on my tractor and excavator were at 100% charged.
After running for 5 mins or more I rehook the battery tender up and it shows that it is charging that the battery is below 80%.
If above 80% a different light blinks so I know both were showing below 80% after running.
In prior years I did not use the battery tender on them and had no trouble starting after they sat a month or so.
I simply do not understand why the battery would show that low after running a bit.
Scratching my noggin here.


Staff member
So today I was checking the Honda 1000 for mileage and hours. It is also set up with a battery tender. I left the battery tender attatched and turned the key to get the digital dash to show me mileage. then I bumped the button to get to hours. All took 30 seconds or so at most.

I checked the battery tender afterwards and sure nuff it showed the red light as if it was charging a battery that was less than 80%. So this appears to be a battery tender issue, in that it is resyncing with the battery before deciding how much charge the battery needs. I have not watched to see how long the light stays at indicating less than 80% but will try to check that tomorrow. For now this appears not to be a battery problem.


Well-known member
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My SIL had a new Craftsman battery charger and I tried to use it to check tlr lights. Found out it won't put out current to anything but a battery with at least partial charge. Had to go get my booster pack to do the job. AH, the wonders of technology!!
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