PowerBook G4 replacing PRAM battery
I have a PowerBook G4 1.25 GHz ("FW 800").
I have the symptoms of a failed/failing PRAM battery- loses date/time.
I have removed the PRAM board and notice:
1. The size of the Panasonic CR-2032 is larger than replacements I have bought
2. The battery measures almost 3.9 V with a volt meter.
So is it probably the entire board that has gone bad rather than just the battery?
And if I wanted to replace just the battery where would I find one that would fit?
Here's the replacement part for the whole thing:
Here's just the battery: PowerBook G4 PRAM Battery
Here's how to install it: PowerBook G4 Aluminum 15" 1-1.5 GHz PRAM Battery Replacement
Keeps track of dates and other crucial system information while computer is powered off — Currently out of stock.
Keeps track of dates and other crucial system information while computer is powered off — 10 available at 24.95 each.
Before taking your PowerBook apart or buying new PRAM batteries, tools, etc., FIRST be sure that your PRAM battery really DOES need replacement.
These batteries are rechargeable and long lived with low self-discharge rates, but if your laptop battery itself is getting old and it's "Health" is getting "weaker", more power and time is used to recharge it and less is available to recharge the PRAM battery.
Apple notes that with a laptop battery with low health, recharging the PRAM battery can require up to 48 hours.
The cumulative charging time needed but not met can result in a PRAM battery that simply is not getting charged enough and can run down so when the laptop is run on battery, the PRAM can lose its ability to retain the necessary information, then lose time settings, etc., go to a dark screen and shut off.
When you plug in to A/C to power up, the time settings will be wrong, it won't log on to your LAN, etc.
Apple recommends testing your PRAM battery when this happens by resetting the time, shutting down, removing the laptop battery and then charging the PRAM battery with the A/C charger for at least 4 hours with the laptop battery removed.
Then reinstall the laptop battery and power up (on laptop battery power only) and let the laptop run for 10 minutes.
If it loses it's time settings again by that time it may need to be replaced (or more fully charged).
If PRAM settings are retained, the PRAM battery may be fine, just having needed sufficient recharging due to an aging laptop battery hogging the recharging power.
I have an aluminum 1.25 G PowerBook G4 with this problem and went through this process but tested before I took my laptop apart.
Happily, the PRAM battery was again able to retain it's settings, so I replaced my laptop battery (which was down to 65% health and over 400 cycles) instead of the PRAM battery and it has been OK.
It had just begun to evidence the problem, losing it's settings and shutting down twice, when running on battery power for a while.
I charged my PRAM battery for about 13 hours, which was probably more than necessary but I wanted to be sure of a good recharge.
Read the support article from Apple, try it and good luck!