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jbleisure · Jul 23, 2006, 08:36 AM

The battery on my PB is history...it's giving me a bout 30 minutes charge. PB is 1bout 15months old now and has been used ALOT.

I will be replacing battery but am keen to understand this from system profiler: it says Amperage -1328. Is that normal? or does that show that the battery is finished?

EdipisReks · Jul 23, 2006, 01:53 PM

run this application and it will give you all the specs on your battery.

Dork. · 04:55 PM

IIRC, the negative amperage measurement simply means that the battery is charging. You can think of the - sign as denoting that charge is going into the battery, not out of it.

Edit: I take that back, negative amperage seems to correspond to discharging....

ghporter · Jul 23, 2006, 04:53 PM

Dork has it. The "Amperage" indication should show you whether the battery is charging or discharging, and how much. That looks like a pretty high charge rate; was your battery very low when you plugged it in?

jbleisure · Jul 24, 2006, 03:11 AM

Thanks for all the input.

That looks like a pretty high charge rate; was your battery very low when you plugged it in?

Basically I have to run the PB with the mains lead in only at the moment.Look at this screen shot of the battery charge just now having taken the mains lead out:

The PB had been plugged in to the mains and on for the past 14hours!

jbleisure · Jul 24, 2006, 03:19 AM

EdipisReks- Thanks - nice app.

Look what I just found out.

jbleisure · Jul 24, 2006, 03:20 AM

Also it was wrong about one thing at least, the cgarger was connected.

ghporter · Jul 24, 2006, 06:19 AM

Originally Posted by jbleisure

Also it was wrong about one thing at least, the cgarger was connected.

If you'd just connected it the app probably just hadn't refreshed yet-I don't know right off how quickly this particular one refreshes. But still, it looks like your battery is pretty worn. There are ways of "refreshing" batteries, but they're never "good as new." I think it's time to do two things: start saving for a new battery, and recalibrate your Mac for your current one. A 17 month old battery that's been well used should stay "OK" for a lot longer, but you also need to allow your Mac to properly gage the charge in the battery-and to properly recharge it so you get the most out of it.

Run the computer on battery until it turns itself off, then charge it completely. This may change the indications you get for battery quality and performance, and it WILL allow you to judge how soon you'll need a new battery.

jbleisure · Jul 25, 2006, 01:51 AM

Run the computer on battery until it turns itself off, then charge it completely. This may change the indications you get for battery quality and performance, and it WILL allow you to judge how soon you'll need a new battery.

Done. Results are exactly as before recalibration. Time for a new battery.

A 17 month old battery that's been well used should stay "OK" for a lot longer

I looked on the online apple store (UK) to see the price of a new battery. (£89 - not particularly cheap but no surprise there). What did surprise me was the several negative reviews regarding the short lives of PB batteries.

skucera · Jul 25, 2006, 10:58 PM

381 cycles for a battery is well over a lifetime, in battery terms. This is off the Apple website: Battery Lifespan:
A properly maintained Apple notebook battery is designed to retain up to 80% of its original capacity after 300 full charge and discharge cycles. You may choose to replace your battery when it no longer holds sufficient charge to meet your needs.

Look at the bottom of the right column if you go to that page. It still seems as if the amount of charge you get is lower than Apple estimates, but then again, what else is new?