Constantly having to reset NVRAM /PRAM

I'm looking at purchasing a Powerbook G4 15" 1.67 from a friend.
This mac will often freeze on boot-up (usually when either unplugged or battery removed) and will only boot once the NVRAM/PRAm are reset with the CTRL-OPT-R-P key combo.

Is there any way around this that I can do to fix it longterm?
Thanks

Replace the PRAM battery in the Powerbook G4 as it might be weak or dead. Check here to learn how: Link

Regards.

Thanks - that looks OK. Havent been able to locate one of the batteries though :-(