Sansa Fuze+ Battery Issue

[...XM]

Hello, I have an issue with the sansa fuze+ battery

A couple of days ago, my 4GB logic board broke and I needed to repair it, luckily, i had a 8GB board and i replaced it with that, however, I noticed that they battery was draining too fast and when i turn it off and on, it will go from 90% to 65% immediately unlike the the 4GB, so as soon it was repaired, I put it back in, but now it still has the same problem, now i did a little asking on the chat forums and they were saying it was a leaking current.

When it was charging, the battery would even decrease, now it's not doing that anymore, which is a good sign

Can anyone help?