How to fix a remote control nikko hummer h2?

I have had my Nikko hummer for about 2 years. It has lately has been losing power and can't turn and if I try to go frontwards or backwards it will do short burst of energy. If I go and turn it off or take out the battery and put it back in it will work for a minute of two and then get the same problem. Can it be fixed and if it can how?|||use a voltmeter and check the battery voltage, over time the battery can loose voltage and current