The lowest is 5.4 shows on my charger and last week(after the cross connected) i can charge it with 0.1 a until it gets to 6v or 7v i can change the current to 5a. But now i charge to 7.4v with 0.1a and i cant get it higher to 5a. Some people said that i got a bad adaptor but i still dont understand how can i check which is wrong? Any advice if my battery get toasted? Any help that i can do to rescue my battery?

Thank you