LQM11.1V 94Wh/8.4Ah New Laptop Battery for Lenovo ThinkPad 55++ T410 T420 E420 T510 T510i T520 T520i W510 W520 57Y4186 42T4799 42T4798

Needed a new battery for my Thinkpad T420. This worked right out of the box and was not blocked by Lenovo BIOS. Photo shows idle capacity of 6-7 hours (at 93%), I tested under cpu load separately and it showed around 2-3 hours for my dual core i5. Yet to test long term use. Overall no complaints.

Battery fits perfectly and charged right up. No issues! Great value!

Fully charged first battery dropped power to the laptop after about 13 seconds when unplugging the power cord. When starting the laptop, you can be unplugged and as long as you don't try to load windows, the battery seems to work fine. Once Windows starts to load, at about 13 seconds, power just drops.Returned the first one and am having the same issue with the new replacement battery.No way to contact the seller and nothing but warnings in the little paper that came with it. I'm going to give it a few days and see if any contact is made. Until then, I'm giving a one star rating until I get a properly working battery.Thinkpad W520. Original battery still works fine, but only has a 15 minute life. I would like to be cord fee. Also, I've searched high and low the original OEM FRU P/N 42T4799 battery, but no luck, not even on Lenovo's web site.UPDATE:I was sent another battery. Basically the same issue. Ran several battery programs, but the battery still shuts off the computer within a minute of being unplugged without warning. Sending this one back also. The search for a working battery is still on.

Works great and stays charged for a long time. Great price and super fast shipping

great replacement great value

battery arrived when it was supposed to that's always a good thing. it was packaged well another good thing. battery fit laptop. checking the charge the battery was @49%. my understanding is that lithium batteries should be shipped at !/2 charge. everything points to true value.........only time will tell. i will update the post if the batteries are anything then what is expected which so far is outstanding!

Very nice to have my W520 up and running again! This battery gives it a good 2-3 hours of use on battery power (Under high performance mode). Not *quite* as good as the factory battery was time wise, but for a 7 year old PC I'm just happy to have it usable. Would definitely buy again, great value for the price.

Will not hold charge. Charged battery up overnight in computer. Computer shows battery fully charged up, but powers off within 1 minute of booting up. Replaced with an official Lenovo battery which charged up fine and works fine.