Hello guys, always in my outddor light energy storage project.
i have written 2 or 3 small questions that come during my work, maybe some of you can answer that :
First concerning the way to build pack, i test all my 18650 from recycled laptop battery.
I have battery's from 1000mah to 2700mah ( LG made exceptionnal work by the way, somecells on a old laptop have awesome capacity ).
My question is : is it true that it isbetter to do :4S5P with exactly same capacity ( for example 20 x 18650 at about 1800-2000mah )
the thing is that i have not 20x sameunits for each capacity.
Can i take a wide range of capacity ( 1600-2000mah )
and do my 4S5P with it, if yes do i need to do 4x2000mah then in parralel4x1900mah then 4x1600mah etc... is that work well ?
2nd question is about rentability of small capacity's cells ( 1000-1200mah ):
if i don't pay the 18650 battery, i ve done a rentability calculation and with 1000mah i can do battery for 90$ / Kwh ( wrap shrink, copper plates, fuses wire, bms, and cell's holder included ) i see people on youtube whosayto don't use cell under 1200mah , but if i m not wrong, it is still profitable to use them if they works no ?
Finally last question is about testing ( wrong category, but better to do 100 different subject on the forum )
I have many used cells who left in laptop during some years, they are under 1V , sometimes 0.25V like that, i put them on my C4 charger, it try to charge them at 1.7V then the voltage of the cell goes up in 4-5second then it changes and charge them at 4.2V..... when i do that the cells are hot ( handle them in hand is possible but still hot ) so to avoid this i charge them in 2 times : 1 hour or less if they became hot quickly then, i let them rest and comeback to ambiant temperature.... then i charge them to full and they works... i do the NOR TEST ( charge, discharge, charge ) and then they are normal , there is a very very small heat ( absolutely like others , and sometimes good capacity , sometimes 700 ( bad ) , 1200 sometimes, 1700-1900....
Question is : Can i conclude it is possible to ressurect a dead cell ? (because on youtube they throw them away and even test it if it is not more than 2V , it seems to be a waste of potential good cells ).
i have written 2 or 3 small questions that come during my work, maybe some of you can answer that :
First concerning the way to build pack, i test all my 18650 from recycled laptop battery.
I have battery's from 1000mah to 2700mah ( LG made exceptionnal work by the way, somecells on a old laptop have awesome capacity ).
My question is : is it true that it isbetter to do :4S5P with exactly same capacity ( for example 20 x 18650 at about 1800-2000mah )
the thing is that i have not 20x sameunits for each capacity.
Can i take a wide range of capacity ( 1600-2000mah )
and do my 4S5P with it, if yes do i need to do 4x2000mah then in parralel4x1900mah then 4x1600mah etc... is that work well ?
2nd question is about rentability of small capacity's cells ( 1000-1200mah ):
if i don't pay the 18650 battery, i ve done a rentability calculation and with 1000mah i can do battery for 90$ / Kwh ( wrap shrink, copper plates, fuses wire, bms, and cell's holder included ) i see people on youtube whosayto don't use cell under 1200mah , but if i m not wrong, it is still profitable to use them if they works no ?
Finally last question is about testing ( wrong category, but better to do 100 different subject on the forum )
I have many used cells who left in laptop during some years, they are under 1V , sometimes 0.25V like that, i put them on my C4 charger, it try to charge them at 1.7V then the voltage of the cell goes up in 4-5second then it changes and charge them at 4.2V..... when i do that the cells are hot ( handle them in hand is possible but still hot ) so to avoid this i charge them in 2 times : 1 hour or less if they became hot quickly then, i let them rest and comeback to ambiant temperature.... then i charge them to full and they works... i do the NOR TEST ( charge, discharge, charge ) and then they are normal , there is a very very small heat ( absolutely like others , and sometimes good capacity , sometimes 700 ( bad ) , 1200 sometimes, 1700-1900....
Question is : Can i conclude it is possible to ressurect a dead cell ? (because on youtube they throw them away and even test it if it is not more than 2V , it seems to be a waste of potential good cells ).