Is Calibration possible in this case ?

[jiroy]

Re: Is Calibration possible in this case ?

Final result ... Upon recharging ,The battery kept at 3% for like 8 hours , and then out of nowhere , it showed 100% fully charged . I'll test it later for stability ..

[stj]

Re: Is Calibration possible in this case ?

nice.

[eccerr0r]

Re: Is Calibration possible in this case ?

Do these charge controllers handle both calibration and balancing? What do the charge controllers do when the cells are not balanced, would the worst cell become the calibration standard?

[stj]

Re: Is Calibration possible in this case ?

interesting question.
i'v guttind over a dozen packs and never really looked at the circuits.
i can say that most are 2x2 or 2x3 or 2x4, and the controller does have a wire from between each pair.
so it can atleast read the difference.
unfortunatly because they are in pairs, when one goes short, it kills it's partner.

[jiroy]

Re: Is Calibration possible in this case ?

Do these charge controllers handle both calibration and balancing? What do the charge controllers do when the cells are not balanced, would the worst cell become the calibration standard?

Unfortunately , yes , the worst cell become the calibration standard , and precisely , the worst cell pack as they come mostly paired . It's always a matter of try and test before we can say it's a reliable battery .

Maybe i should mention also that when soldering , you cannot put heat on the battery directly , it would kill it instantly ..

[eccerr0r]

Re: Is Calibration possible in this case ?

Then how do mere mortals (i.e. those without welders) reconnect li-ion cells?

[stj]

Re: Is Calibration possible in this case ?

by cutting then out with stubs of the original tabs still in place when you salvage them.

[diif]

Re: Is Calibration possible in this case ?

Pretty sure I've seen Mr Carlson solder tabs to cells quickly with an iron then using a damp cloth to dissipate the heat.

There was an article on Hackaday a while ago about battery controller hacking. https://hackaday.com/2016/09/03/tour...ttery-hacking/ that linked to this page http://www.karosium.com/2016/08/smbu...batteries.html
Maybe it's of some help ?

[eccerr0r]

Re: Is Calibration possible in this case ?

I tried the stub method but the problem is that the strips of metal are quite a bit thinner than copper wire and solder blobs and the cells no longer fit in the original package... boo.
Perhaps "thin" 24AWG wire is sufficient but I suppose it depends on the application. I was trying to rebuild a power tool and knew that the thing would be drawing upwards 15A or so (10C discharge rate) and had to use thicker wire to stitch the cells together... and ended up with something I can't put back together again...

[jiroy]

Re: Is Calibration possible in this case ?

Yes , It's a very delicate job , it need nerves and patience . I sell like 50 Laptops batteries per year in average , and usually i keep the defect ones , so i have to admit , I have MUCH more choices in choosing the right straps Length and welding positions .