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Acer Aspire 5742 new battery installed, but laptop shuts off when charger removed, old battery works ok but only lasts 10 mins

  • Battery
  • Aspire
  • Computers
  • Acer
Last response: in Laptop Tech Support
July 25, 2015 2:02:56 AM


I purchased a new battery a few days ago. I recieved it today. It is a "Replacement Notebook battery for Acer Aspire 5742 10.8 volt Li-ion advanced pro series laptop battery 6600mah/71Wh." There is also labeling that states LAC215X-AP and another part of the same label stating AS10D41(31CR19-66-2) 4741. My computer is a Acer aspire 5742G-6600. My old battery was the original battery that shipped with the computer and has lost its ability to charge. I can run my computer with the old battery for about 5-10 minutes unplugged--this will be important later--see below. My old battery is an AS10D51(31CR65-2) (4400mah/48Wh).

When I put the new battery in my computer, the computer immediately recognized it was attached and reported that it was at 50% charge. I turned the computer off and left it for a few hours. It charged to 100% and I began using the computer. After about an hour, I unplugged the computer and ran it for several hours without problem. Then, suddenly, the computer just shut down.

I don't know what the battery level was at the time because I was watching a movie fullscreen.

It was very sudden and surprised me because usually the computer shuts itself down slowly when it runs out of power to protect currently open files. I thought it was a fluke so I connected the charger and turned the computer back on. After booting, it reported that the battery was at 68%. Odd. I tried unplugging the charger and the computer immediately shut off again. I left the computer to charge for awhile but it didn't budge from the 68%.

Concerned, i plugged my old battery back in to see if it was my computer, and not the new battery. Alas, my computer will still run for about six to ten minutes when unplugged with the old battery--so I know it's not my computer or charger (still using the same one that came with the computer). I tried updating my battery drivers through device manager, but they seem to be up to date. I've asked it to recognize new hardware. I tried flashing my BIOS, but none of this seemed to have any effect didn't help.

I have tried powering down the computer, disconnecting the charger, and removing the battery, then I held the power button down for 45 seconds because some thread online said that sometimes its necessary to remove residue charge in the computer, but that had no effect (didn't expect it too).

I've tried removing the batteries entirely and running the computer without them (just using the charger) and it runs fine, of course this is not a long term solution.

If the old battery is plugged in and the charger is attached, turn the computer on, and then remove the charger, the computer runs for 10 mins and then goes into emergency shutdown procedures to protect currently open files. But when I do the same procedure with the new battery, and then I remove the charger, the computer immediately shuts off, like a light switch, with no emergency procedures. As I've mentioned above, this leads me to believe that its not my charger or computer.

Could it be a software issue?

I am at a loss. Do you have any suggestions? Guess it could just be a lemon battery.

More about : acer aspire 5742 battery installed laptop shuts charger removed battery works lasts mins

Best solution

July 25, 2015 6:41:44 AM

Sounds like your battery is a poor quality aftermarket piece of junk. Return it.
Ive found most of the aftermarket ones are just rebuilt used ones. I havent had to buy any in a while but I used to have very good results with Anker Direct

Good luck.
February 21, 2018 5:57:13 PM

Hi soapiper, did you ever find a solution to your problem? i have the exact problem with my Toshiba Click. Your description fits my efforts exactly and i find it a shame that no one could reward such a fine effort at detailed description with a resounding fix of some kind. That is a lot of time invested in seeking a solution. Did younever find one?
6 minutes ago

Sadly Soapiper has never returned.
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