T43 charging problems, even with new battery

[npatel0110]

I have resurrected a ThinkPad T43 and everything is working great (the motherboard was replaced about 2 years ago so it's kind of like an old car with a new engine). Except for the battery. I have the original battery, which lasts about 10 minutes. So, I bought the extended battery (6600 mAh, 9 cell).

I installed the new battery but it will only charge (slowly) to about 7-10% and then quit. The original battery charges oddly. I discharged until sleep, then plugged it in - it charged to 49%, stalled, and a few minutes later said "On AC power" with a charge of 100%.

With the new battery, it hits that 7 or 8% area, then stops charging and says "On AC power", but does not charge further.

All BIOS, power management utilities, etc. are up to date.

Also, the new battery is indeed new, as the wear was at 0% and the rated capacity is almost exactly what would be expected of the 9 cell version.

Could this be an AC adapter problem, or something deeper? I haven't had the chance to try a new adapter, or try the battery in another computer...mainly because there aren't a bunch of T43s lying around on campus...

Thanks for any help!

[ajkula66]

Welcome to the forum!

Is your new battery a genuine IBM/Lenovo one, or a third-party replacement?

Your charging circuit may be damaged, at least that's what it sounds like to me from your description...

[npatel0110]

Thanks for the welcome, and thanks for the incredibly prompt response!

I bought it on eBay, and it says OEM compatible so it's probably not a genuine Lenovo one.

So, I did another experiment and discharged the original (old, 6% health) battery to about 70% and plugged it back in. It seemed to charge in a normal manner to 100% and then stop charging. Still kind of weird that it did NOT charge normally when discharging it to empty and charging back up.

In writing this, it kind of seems like the replacement battery is the issue...

I'm having a friend send me a replacement extended battery (not sure if his is Lenovo or third party) that definitely works, as well as an AC adapter, so hopefully I will be able to diagnose the problem.

In the case that it is the charging circuit, however, is there a solution?

[npatel0110]

By the way, here's the readout from the ThinkPad Power Manager with the new battery, plugged in:

Status: No activity
Remaining percentage: 9%
Remaining time: -
Remaining capacity: 5.49 Wh
Full charge capacity: 64.63 Wh
Current: 0.00 A
Voltage: 11.96 V
Wattage: -
Temperature: 24 C
Cycle count: 1
Manufacturer name: SANYO (so definitely not OEM)
Manufacture date: 2009-11-23
First used date: 2010-01
SerialNumber: 33
Bar-Code number: 1ZAW063V1ED
FRU part number: IBM-08K8193
Device chemistry: Li-Ion
Design capacity: 61.56 Wh
Design voltage: 10.80 V

[ajkula66]

Let's see how your machine behaves with a different battery and we'll take it from there.

Hopefully there's no damage to the charging circuit since that type of repair equals board level soldering at best...

[rkawakami]

@npatel0110: Just a sanity check question from me... what is the wattage of the AC adapter you are using; 54/56W (3.36A) or 72W (4.5A)? I ask because the T43 is spec'ed to use a 72W supply and if you have the lower wattage adapter then that may explain your battery charging problem.

[npatel0110]

I'm using the original IBM AC adapter - 72 watts.