Batterygate: Apple's Dysfunctional iPad 3 Battery Charger

[HarryT]

Originally Posted by murraypaul

Isn't it standard with Lithium batteries that until you've done a full discharge-recharge cycle the battery level display isn't 'trained' correctly, and won't display the correct figure?

It's certainly true that on some devices, the firmware requires a number of charge/discharge cycles to accurately calibrate the battery meter, but that has nothing to do with the actual battery itself.

[murraypaul]

Originally Posted by HarryT

It's certainly true that on some devices, the firmware requires a number of charge/discharge cycles to accurately calibrate the battery meter, but that has nothing to do with the actual battery itself.

Right, that is what I said, that the battery level display was not correct.

[murraypaul]

Originally Posted by obsessed2

In other words 100% on the battery meter does not mean your battery is 100% charged, it really means it's 90% charged. Imagine if your car's gas gauge said you had a full tank but in reality it's only 7/8 full. If you have a 20 gallon tank that's 2.5 gallons short. If your car gets 30 miles a gallon this means you can drive almost an extra 100 miles before fill up. If your battery is at 100% instead of 90% you get an extra hour of use before having to recharge.

... assuming that all iPads behave in the same way as the one that this entire discussion is based on.

[HarryT]

Originally Posted by murraypaul

... assuming that all iPads behave in the same way as the one that this entire discussion is based on.

It wouldn't surprise me if that were the case. On my Dell laptop, for example, the "charging" light goes out when the battery is just over 90% full, and it then takes longer to get from 90% to 100% than from 0 to 90%.

[obsessed2]

Originally Posted by murraypaul

The memory effect is something different.
That was about it being bad for the battery to keep topping it up.

I may have misunderstood your other post where you mentioned charge-discharge cycle. You used to have to completely discharge older batteries before recharging because of the memory effect. The lithium battery can be charged regardless of its current percentage and it has absolutely no negative effect on its performance. In other words topping it off is not going to hurt it.

[obsessed2]

Originally Posted by HarryT

It wouldn't surprise me if that were the case. On my Dell laptop, for example, the "charging" light goes out when the battery is just over 90% full, and it then takes longer to get from 90% to 100% than from 0 to 90%.

You hit the point exactly. On your laptop the charging light goes out at just over 90% full and is reported as such. It doesn't go out and report the battery as being 100% charged. It continues to trickle charge to 100%.

My Viewsonic gTab it says fully charged at 96% at which point I unplug it. I don't charge it overnight. However, the next time it needs a charge I'm going to leave it on the charger an extra hour and see if the battery meter will actually register 100%.

[Rob Lister]

Originally Posted by obsessed2

Imagine if your car's gas gauge said you had a full tank but in reality it's only 7/8 full. If you have a 20 gallon tank that's 2.5 gallons short. If your car gets 30 miles a gallon this means you can drive almost an extra 100 miles before fill up.

I don't really need to imagine it. that's pretty much how it behaves now. yours doesn't ?

[obsessed2]

Originally Posted by Rob Lister

I don't really need to imagine it. that's pretty much how it behaves now. yours doesn't ?

Maybe on my 1994 Hyundai Soupe but I would hope not on my 2009 Toyota Yaris. And if I bought a 2012 model I would certainly hope the gas gauge wasn't that inaccurate.