Forget about it. "Dehydration" likely is NOT the cause of the probem. There is NO WAY to pump new life into a worn out battery.......no matter what type it is. Some procedures will appear to give it new life......for a few days or weeks before it totally fails.
Your profile says other hybrid. Likely and Prius specific advice you get here would not apply and can be dangerous.
Lexus gs450h I done it ..the problem is something car is going over 2 km somtime its not start..car is not change motor to engine or engine to motor ..