PowerBook Battery

hi everyone, could do with some help regarding a battery issue im having with my powerbook (G4 15" FW800)

issue

Battery wont charge
Displays charge status - 0%
Displays charging status - Calculating

tried

Resetting NVRAM/PRAM/PMU
Booting into open firm and resetting nvram and all

tried finding someway of flashing the battery firmware but i cant find anything

ideas

Well the computer initially wouldnt boot even with the power adaptor plugged in.
Resetting the PMU sorted this but needed to be done everytime the computer was shutdown.
Soft reboots work fine,

I've tried with another battery and it works fine, so clearly its a specific battery issue.

The powerbook understands when there is and isnt a battery (menubar symbol), it reads all the info off the battery (sys profiler) .. it just wont charge it!


any help much appreciated

 

yeah unfortunately the battery im currently using only gives me about 20mins, its the original powerbook battery - the newer one is the not working one


i had a look before, but i just realised i should compare the specs across the 2 batteries i own.

Working (Old) Battery Information:

Charge Information:
Charge remaining (mAh): 972
Charging: No
Full charge capacity (mAh): 974
Health Information:
Cycle count: 185
Battery Installed: Yes
Amperage (mA): 0
Voltage (mV): 12384

Broken (New) Battery Information:

Charge Information:
Charge remaining (mAh): 0
Charging: No
Full charge capacity (mAh): 1806
Health Information:
Cycle count: 210
Battery Installed: Yes
Amperage (mA): 0
Voltage (mV): 9434


note the working battery is a good 2 years older than the broken battery, i dont understand why a newer battery with a still higher capacity doesnt work.

is it something to do with the voltage? im kind of curious as to why thats dropped so far ...


thanks for any help on this guys, this has got me confused, do batteries just drop out and die? i was under the impression they progressively lost capacity untill they were essentially useless ...