Thinkpads Forum

i've read elsewhere that the sudden turn off is because the laptop cannot get an accurate charge level from the battery and dies w/o warning simply because the battery ran out

Can anyone confirm this is an acceptable explanation OR has this happened to properly attached and at least 10% charged batteries in a laptop that wasnt being moved around?

I've seen laptops (not a Thinkpad) tell me that a battery which had a 100% charge last week, was dead this week. And since they were Compaq gen-you-whine batteries, which have an LED battery charge indicator strip on them, I could confirm that the Li-On battery was indeed totally dead just one week after being 100% good, and practically unused. (They were the spares.)

Seen it repeatedly. Li-On batteries are simply unreliable after they are ~~2 years old.

it's a good idea to calibrate any new battery before usage. let it go to zero and let it charge to full. i had one battery that i forgot to calibrate now it shuts down at 70 percent. can't get it to go below that. all my other ones work fine. oem and aftermarket.

some of the aftermarkets have crappy contacts that bend on contact. i had to bend them back out with a feeler gauge.

I purchased a non-oem battery for my old t43p on ebay and it worked almost perfectly. The only issue I ever had with it was that Power Manager would show the "time to replace your battery" message, saying that the battery could only hold 100% of it's original capacity. Oh shame... I turned off the notification and the battery worked great, still held an all-things-considered decent charge when I sold it.