Obviously you can charge a discharged battery to the opposite polarity.
My neighbor did it by accident.
To fix the problem, you have to discharge the battery again and recharge in the correct polarity.
Your battery charger and timing light may be reverse polarity protected so they don't self destruct.

Last edited by buoymaker; 05/25/2021 1:00 AM.

"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."