Odd PB 1400 battery behaviour

KLK wrote on :

In article BB19EEF5.3E895%pfgpowell@redacted.invalid, Patrick Powell pfgpowell@redacted.invalid wrote:

I was getting very little out of my two 1400 batteries (30 mins at most) even though one was bought by me brand-new and had not really been used. I had the PRAM battery replaced, and thought that did the trick. But now the old battery shows up but the 1400 cannot 'see' the other, newer battery. Before I cart ther 1400 to an expensive Apple mechanic, can anyone suggest possible solutions? Could it be that when the PRAM battery was replaced some connection or other (between battery and 1400 ?) is too loose?


First thing is try resetting the power manager. If the power manager gets confused then it won't treat any battery correctly. I seem to remember that you pull out the battery and power plug and hold the reset button for 30 seconds. Then reset the PRAM parameters. This should have been done with the PRAM battery replacement but it can't hurt.

However, the fact that the the machine can see one of the two batteries indicates the problem is probably not the 1400. There are two things that could cause your problems.

I'm betting that the "old" battery is suffering from aging of the NiMH cells. When NiMH cells get old, 2-3 years, their charge capacity drops drastically. Thirty minutes or less is not unusual.

If you can't see the "new" battery after resetting the power manager then the IC, or maybe the thermal switch, in the new unit may have failed. If the IC goes, then the 1400 won't recognize it as a battery, no matter how much voltage is available. If the "new" battery is still under warrenty, then the manufacturer should replace it.

If the battery is to old, then it is possible to open both batteries and pull the IC out of the "old" battery and put it in with the newer cells. Then you still should have one decent unit.