Battery charging very slow then stops

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buzzliteyear · #1 Post by **buzzliteyear** » Mon Oct 30, 2017 6:57 am

Hi Guys,
Ive had my t420 for about 3 years and the last time I used it from battery alone was a couple of weeks ago as we often have
power cuts etc and the battery always last great and did last time also......this morning when I tried to turn it on the battery was so dead it would not power up.

I had a spare battery that is crap to test it but it did power up for a few seconds

So I know the battery is ok in my first pack but something is telling my laptop they are not.......

I ran the Bat reset and did not help......

I have a box of 100+ laptop batterys I got second hand for a project they were meant to be faulty/old batterys. 90% of the 18650 cells inside have over 60% of the capacity still left......

is it the circuits that fail ? can I fix mine ? its a 9 cell 94Wh pack

Cheers
Brett

Thinkpad4by3 · #2 Post by **Thinkpad4by3** » Mon Oct 30, 2017 7:12 am

Its not the cells, it is a faulty power circuit. You need a new battery, not new cells. Ive seen this happen with my X61 battery.

buzzliteyear · #3 Post by **buzzliteyear** » Mon Oct 30, 2017 4:38 pm

Ok thanks.....anyone tried to fix the circuit ? im ok on a re-flow station etc

Thinkpad4by3 · #4 Post by **Thinkpad4by3** » Mon Oct 30, 2017 6:26 pm

If you can reverse engineer a proprietary chip and find a donor to swap while keeping constant current on the low-voltage detection circuit, be my guest. Or....you could just go on eBay and get a brand new OEM battery for a tad over 30$. Your choice though.

https://www.ebay.com/itm/Genuine-Origin ... Swr~lYrkVh

ajkula66 · #5 Post by **ajkula66** » Mon Oct 30, 2017 7:29 pm

buzzliteyear wrote: ↑
Mon Oct 30, 2017 4:38 pm
Ok thanks.....anyone tried to fix the circuit ? im ok on a re-flow station etc

Will the machine power on AC adapter only, with no battery inserted?

buzzliteyear · #6 Post by **buzzliteyear** » Mon Oct 30, 2017 7:57 pm

yep cool....just have to find a seller that ships to New Zealand.......

buzzliteyear · #7 Post by **buzzliteyear** » Mon Oct 30, 2017 7:59 pm

Will the machine power on AC adapter only, with no battery inserted?

Yes works fine but is slower than normal.....I had tested running without the battery before when battery was fine and
it did the same thing.....a little lagy

ajkula66 · #8 Post by **ajkula66** » Mon Oct 30, 2017 8:10 pm

buzzliteyear wrote: ↑
Mon Oct 30, 2017 7:59 pm
Yes works fine but is slower than normal.....I had tested running without the battery before when battery was fine and
it did the same thing.....a little lagy

My best guess is that the problem is within the laptop's charging circuitry and not with the battery itself. However, the only way to verify that would be to verify how the machine behaves with a *known good* battery inserted.

buzzliteyear · #9 Post by **buzzliteyear** » Mon Oct 30, 2017 11:27 pm

Good point. I have recommended these laptops two close mates so will borrow one and test

Battery charging very slow then stops

Battery charging very slow then stops

Re: Battery charging very slow then stops

Re: Battery charging very slow then stops

Re: Battery charging very slow then stops

Re: Battery charging very slow then stops

Re: Battery charging very slow then stops

Re: Battery charging very slow then stops

Re: Battery charging very slow then stops

Re: Battery charging very slow then stops

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