Battery charging very slow then stops

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buzzliteyear
Posts: 6
Joined: Sun Jun 28, 2015 1:51 am
Location: Auckland, New Zealand

Battery charging very slow then stops

#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
ThinkPadder
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Location: N. Bellmore, ny

Re: Battery charging very slow then stops

#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.
Welcome to the jungle, we have FrankenPads
If you want it you're going to bleed, but that is the price to pay
And you're a very rare mobo, very hard to get
You can see the blinky lights, but you won't get them for free.

buzzliteyear
Posts: 6
Joined: Sun Jun 28, 2015 1:51 am
Location: Auckland, New Zealand

Re: Battery charging very slow then stops

#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
ThinkPadder
ThinkPadder
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Joined: Sun Aug 09, 2015 9:25 am
Location: N. Bellmore, ny

Re: Battery charging very slow then stops

#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
Welcome to the jungle, we have FrankenPads
If you want it you're going to bleed, but that is the price to pay
And you're a very rare mobo, very hard to get
You can see the blinky lights, but you won't get them for free.

ajkula66
SuperUserGeorge
SuperUserGeorge
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Joined: Sun Feb 25, 2007 11:28 am
Location: Brodheadsville, Pennsylvania, USA

Re: Battery charging very slow then stops

#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?
...Knowledge is a deadly friend when no one sets the rules...(King Crimson)

Cheers,

George (your grouchy retired FlexView farmer)

AARP club members:A31p, T43pSF

Abused daily: T61p

PMs requesting personal tech support will be ignored.

buzzliteyear
Posts: 6
Joined: Sun Jun 28, 2015 1:51 am
Location: Auckland, New Zealand

Re: Battery charging very slow then stops

#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
Posts: 6
Joined: Sun Jun 28, 2015 1:51 am
Location: Auckland, New Zealand

Re: Battery charging very slow then stops

#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
SuperUserGeorge
SuperUserGeorge
Posts: 15987
Joined: Sun Feb 25, 2007 11:28 am
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Re: Battery charging very slow then stops

#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.
...Knowledge is a deadly friend when no one sets the rules...(King Crimson)

Cheers,

George (your grouchy retired FlexView farmer)

AARP club members:A31p, T43pSF

Abused daily: T61p

PMs requesting personal tech support will be ignored.

buzzliteyear
Posts: 6
Joined: Sun Jun 28, 2015 1:51 am
Location: Auckland, New Zealand

Re: Battery charging very slow then stops

#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

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