T61 Battery Charging Issue

[mechanic]

I replaced the dead MB of my T61 three weeks ago with a used MB, bought off our marketplace from a reliable seller. The replacement was smooth with all components working as they should. In fact, after replacing my nVidia graphics based MB with Intel graphics MB, i have found my T61 to have remarkable times to snap in and out of Standby mode (4 sec utmost).

The only issue i face now, is battery charge times. My original T61 battery takes forever to get charged. I found the charging rate to be ~ 0.5% per hour.

From my understanding, the possible causes for my issue can be the following:

1. Failing/ dead battery - Not a issue. As my T61 battery charges just fine in my new R400 while, the brand new R400 battery takes forever to get charged in my T61.

2. Bad power brick - Not an issue. Used my R400's new power brick, but makes no difference to the charge times.

3. Power manager settings- I have always used my power settings for my 6-cell battery:
>>>> Charging starts if < 40% and stops at 80%.
>>>> Cycle count: 186
>>>> Battery condition: Good (Green).
>>>> First use: Oct 2007.

4. Charging circuit in MB - Could this be the issue? Looks like it is not completely fried as it still puts some charge in the battery.

5. BIOS update - After replacing my MB, i did a BIOS update using Lenovo update manager. Could upgrading the BIOS be the issue? Should i try reverting my BIOS to older version using bootable CD?

I appreciate your suggestions to help me troubleshoot this issue.

Thanks !

[Harryc]

Based on your description, my opinion is that it could absolutely be a problem with the charging circuitry on the systemboard. Can you contact the seller to get a refund or replacement?

[jimmy274]

Probably charging circuits. Basically, there's 3 things that could go wrong with this:
1. Power mosfets,
2. Fuses,
3. Li-ion battery control ic.
Power mosfets used for charging/discharging are very ESD sensitive, meaning touching them a lot is not advisable unless you'd want to fry them for some reason. I've been pleasantly suprised when I saw that these are tape-protected on my x60s, as they are usually not protected by anything, they are somewhat thicker than the rest of the circuitry and usually on the edge of the board (yes, I'm implying that they're just screaming:"Touch me!!!"), and the behavior that you're experiencing sounds like a bad mosfet (ie - they're not like fuses and could be partially fried, meaning they could still transfer some energy, while leaking the rest through the gate driving circuitry or dissipation... yes, not very good for gate driving circuitry or the surrounding components).
Fuses are easily diagnosed, as they are pretty much ON or OFF, meaning charging or not charging - there is no partially charging scenario, so it's not that.
Battery control ics share similar effect to fuses - it's either they work or not. Pretty often you can't even start your laptop if they died, so I would rule these out.
The worst would be a bad trace (ok, I lied - there's 4 things) - this would also fit, but there's no solution for it. Even though mosfets are cheap and every electronics service shop could find and replace them in a few seconds, I would still try to get a refund from the seller or a replacement...