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.