little used battery dead. What should I do with fru 42t5247?

[rychuu]

hello,

I have nice light battery for x61 - but when I got it after long time without using it has condition poor in power manager.

Led on the lcd is blinking fast in orange.

Is it any way to use it as a battery, not only a spacer? It s very nice, its light and small. Its very important for me.

best regards

[AGoodSolution]

hello,

I have nice light battery for x61 - but when I got it after long time without using it has condition poor in power manager.

Led on the lcd is blinking fast in orange.

Is it any way to use it as a battery, not only a spacer? It s very nice, its light and small. Its very important for me.

best regards

Obviously you can try the ThinkVantage Power Manager / Battery Rest but it seems like yours may be too far gone.

BUT, instead of throwing it away, keep the dead battery for its shell and buy an aftermarket replacement, they have varying degrees of quality but most battery power cells are still manufactured by a handful of companies for OEM's and aftermarkets. Although the cells may be the same, what is consistently bad is aftermarket batteries fit and finish, often oversized in the wrong places and with useless latches.

Disassemble the new aftermarket battery and transplant the new cells into your dead battery shell along with the controller circuit, instructions are widely found on Google. I've successfully done this with numerous T43 and X41 batteries.

The forum trolls will likely invade this posting with warnings to avoid aftermarket batteries or additional advocacy to follow my advice. I already know who the non oem battery haters are and their blah blah but they never offer evidence supporting their jihadic assertions except they just know in their hearts it is the right thing to keep buying OEM parts no matter what.

In some cases, you can't find OEM batteries or in the size you want and aftermarkets are the only choice.

[Cigarguy]

^^ Care to provide any link to sites that provide good instructions on how to disassemble a battery? Maybe my googling skills is not that good. It's not something that I'd like to do frequently but would genuinely like to learn just for kicks.

[rkawakami]

Just an FYI, but Mr. Solution has decided to part company with the forum.

[RealBlackStuff]

And good riddance! His belittling know-it-all posts were getting on my nerve!

[dmdsoftware]

With your next battery, I suggest you make use of the stop and start thresholds. It's the constant topping up that tends to kill these batteries, from what I have noticed. I'm a long term user of the X series, and in the X6* series, the batteries have this new self-destructing feature if the voltage goes out of balance.

I have my thresholds set at START=50% and STOP=80%. My X61T-SXGA is still with it's original battery (4 years old), also my X61T-touch. I'm on my 5th battery for the X61 (5 years old), only because I never learned about this feature (which is provided in the Thinkpad Power Manager software or via Linux thinkpad_acpi) until battery #4. Battery #4 kicked the bucket with the rapid-blink-death after I had leant it to another another X61 user who used it without and START+STOP thresholds for 2 days before killing it.

My current battery (#5) I won't allow plugged into any machine without proper charge thresholds set.

Here's the battery stats:
@x61-ssd [50C] [12808000] /sys/devices/platform/smapi/BAT0 $ cat cycle_count
131
@x61-ssd [50C] [12800000] /sys/devices/platform/smapi/BAT0 $ cat first_use_date
2010-11-24

Approaching end of year #2, using this machine 365 days a year (and I frequently work untethered from power, like at the time of this post).

[pgoelz]

With your next battery, I suggest you make use of the stop and start thresholds. It's the constant topping up that tends to kill these batteries, from what I have noticed. I'm a long term user of the X series, and in the X6* series, the batteries have this new self-destructing feature if the voltage goes out of balance.

I have my thresholds set at START=50% and STOP=80%. My X61T-SXGA is still with it's original battery (4 years old), also my X61T-touch.

Ordinarily that would be excellent advice to maximize battery life.

However......

I can't prove it but I have a hunch that if you set a STOP threshold lower than 100%, it is more likely that the battery gauge will get out of synch after multiple charges or lengthy periods on AC power only. My guess is that for thresholds < 100%, the battery manager uses the reported (calculated) state of charge to determine when to stop charging. For 100% it uses the actual cell voltage and stops at 4.2V/cell regardless of what the manager reports.

I have a good performing aftermarket battery that I had set to start at 85% and stop at 95%. After a couple months of AC-only use, it was reporting it was 95% charged one day and I pulled the power cord. It ran for about 5 minutes (reporting about 90% charged) and the machine suddenly claimed it was dead, showed about 5% remaining and hibernated. This was a pack that I had opened and replaced the cells with genuine Sanyo only a couple months prior, so I was surprised. I re-opened it and measured the cells and found that A) they were in balance and B) they measured around 3.5V/cell, consistent with a low state of charge.

Since they were essentially new, I figured it had to be the battery manager that was the problem. I did a battery gauge reset and the battery is now performing normally again.

This particular pack (Chinese) tends to discharge at about 0.5% to 1% per day even on AC power. I assume this is because the battery manager consumes more current than an OEM pack. My guess is that this causes it to slowly discharge, hit the start threshold, charge up and then stop much more frequently than an OEM pack. If the current measurement circuit is not accurate (or more likely, does not correctly resolve and measure the very low level constant discharge current) the manager can over time think the pack is at a higher state of charge than it really is.

Since I can replace the cells in this pack if/when needed, I decided to set the battery manager back to 100% stop and 95% start and accept the lifetime hit.

We would have a LOT fewer battery issues if the manufacturers would stop trying to measure actual power in/out and simply relied on cell voltage to determine state of charge. No, it would not be as accurate and it would not be able to accurately predict remaining run time. But it would eliminate all the battery gauge issues and the need to reset the battery gauge.

IMO, anyway.....

Paul