Bot battery not charging

Bot is out on charging since more than 24 hours now and the battery percentage has dropped from 5% to 3% now.  It’s simply not charging. Have tried all trouble shooting shown by google.

PLease check the carging contacts and clean them properly if you see any black line or spot on it

Maybe try cleaning the charging magnets if it doesn’t work replace the magnets on the robot or the battery might be the battery issue