ow wow...this sounds like not really how it should be!
I bought a cheap ebike back in 2017 which can take 50 kms and charging takes just 2 hours. A totally different story.
But uhhh..especially that you battery heats up, that shouldnt be happening at all..Watch out with this
Fortunately not the battery itself but the charging device gets hot. This issue is also known from USB chargers or power bricks which also can get quite hot.