TiBook battery reporting wrong information

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Level 1

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TiBook battery reporting wrong information

I recently got a TiBook 1GHz, and of course it being used, there was no guarantee on the battery life. I was also given a third party 45W charger, so I wasn't expecting anything spectacular. I loaded Tiger on it, left it to charge overnight, and unplugged it and pulled it out in the morning to start loading some newer browsers and other software. But then it tells me that with my backlight low and on battery saving mode, It will last 7 hours. And then it started draining as to back it up. The percentage was going down slowly, the estimated time was dropping like it should, and I was about to wonder what kind of battery this was.

Then the inevitable happened, and it went into the dead battery standby. Clicking the button on the battery anytime right up till it 'dies' reports what the OS sees, so at 75% its got 3 lights, and at 50 or so, its got two. But then when it dies, it goes straight to a single flashing light.

I've already tried resetting the PMU, resetting the PRAM, and doing the normal battery meter reset (as far as I know it), but it still reports a false reading.

The guy I bought it from claimed ~4 hours on the battery. And that's about what I get, with standby times and moments of high usage taken into consideration. And the reported time ticks away correctly. After the meter reset, it told me 7 hours. when it died, it said 3 hours. But I kinda need to know a more acurate reading for when I start using it more often.

IIRC, the meter reset is charge it up fully, discharge it by using it, let it standby when the battery 'dies', and then charge it up again. It should then be reset and more acurate. But, do I need to have the computer on and active during the charge, discharge, and second charge stages? can I let it go to sleep? Will a 65W charger fix this problem? Or is my battery just dead? I can't afford a new battery just yet, but what's the opinion on the best brand?

EDIT: I just grabbed a utility called coconutBattery and ran it, and I'm thinking the battery may be a bit too far gone...

It says the Original battery capacity was 4200mAh. But its reporting that the current capacity is somewhere in the 7000mAh range. What on earth could that mean? I don't think the battery has been rebuilt or anything (it certianly doesn't look like it). But Its giving me some pretty bad readings in OS X Tiger. The computer came loaded with OS X Leopard and was running slow as molasses...Could the OS switch have changed anything?

Any help would be appreciated.

-Atari

Message was edited by: Atariangamer

PowerBook, Mac OS X (10.4.11)

Posted on Dec 31, 2011 9:32 PM

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Answer 1

Jan 1, 2012 12:49 AM in response to Atariangamer

Coconut Battery picks data from the system, it is just a friendly interface of sys info. You describe a seemingly erratic behavior of your battery, probably its controller. Cannot say whether the charger may be the problem for this false readings, the 45 W charger may be OK according to Mactracker.

For that generation, it would be perhaps useful to use battery until iB goes to sleep, then immediately connect charger, then keep it 2-3 hours after battery full. Repeat this once more.

If reading battery info is also erratic, perhaps you cannot do anything more than live with this. If it keeps 3 hours, it seems OK to me.

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Answer 2

Jan 1, 2012 11:02 AM in response to Atariangamer

From my experience, what you are seeing is a battery on its last legs. I have had this happen a couple of times over the years, with the battery going from 75 percent to sleep dramatically. Solution is to get a new battery. Battery life does vary, as I have one battery that is probably eight years old that is almost like new, another of similar age that is well serviceable, and a couple of paperweights from that time frame.

I have had good battery luck here.

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Answer 3

Braby

Level 4

1,795 points

Jan 1, 2012 2:56 PM in response to Atariangamer

"The guy I bought it from claimed ~4 hours on the battery. And that's about what I get, with standby times and moments of high usage taken into consideration."

It seems to me there are two issues here. One is the erratic and unaccountable reporting of the charge remaining, the other is the state of the battery. I can't offer any advice on the first problem, but can we just clarify what this battery is actually capable of? The only real way to measure this is how long from fully charged to fully discharged while the computer is powered on. In my experience with a healthy new battery my PowerBook would provide maybe 2 hours or so of moderately processor-intensive use. As the battery aged this would gradually reduce until the point where it would last only a few minutes. Sometimes this would be accompanied by unreliable readings of remaining time/percentage.

I was never in any doubt as to when it was time for a replacement.

A dying battery will also discharge itself rapidly even when removed from the computer.

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Answer 4

Jan 2, 2012 1:40 AM in response to old comm guy

According to the description, the battery does not seem to die, it just seems to give erratic info about its state.

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Answer 5

Atariangamer Author

Level 1

0 points

Jan 2, 2012 11:06 AM in response to Atariangamer

Okay, after messing with it some more, I've got a better understanding of what this thing is doing.

The original claim by the seller was ~4hrs of battery life. When I put it in the machine, fully charged, Tiger reports it as almost 9 hours of life in full power save (low backlight, no airport, hard disk off, battery saving power mode). The percentage and time tick down like they should. Right up until ~75%. It goes to sleep, and cannot wake up until power is plugged in. When power is plugged in, it now claims the battery is at 0% and will take about 5 hours to charge.

2 hours later, its fully charged, and still claiming that high life time.

I looked in the system profiler, and its saying that a full charge on the battery is 7539 mAh. The battery only held 4200 when new. This battery also only has 102 cycles on it. If you subtract 4200 from 7539, you get 3339, which when I take into consideration that it lasts about 2-3 hours with normal usage, that seems about right. But the system is miscalculating EVERYTHING because the battery reports itself as its original capacity PLUS its actual capacity, so when the battery stops charging, it assumes that instead of 3339 (which it should report to the system right up untill the battery clicks to 100%), it should be at 7539, and then it skews the whole thing.

I have it charged to only 15% after it went to standby, and its reporting the time and percentage fine, but as soon as I try and load a full charge, the time and percentage will skew again.

I've tried everything again to see if I can fix it up, but nothing seems to work...

I'm about to load Panther on another partition. See if maybe its a software problem...But I'm thinking its just the battery's 'fuel gauge' isn't working right.

This is just a really odd case, but I've had a similar experience with a 12" G4. Its battery was much more used, but would say it could hold 3 hours, but just after an hour elapsed, it would quickly reallign and tell me that I only had a few minutes left. I didn't think to check capacities and whatnot back then, mostly because it was a job to see if I could even get the computer to work after someone had pulled the screen out of it.

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