Quote
C:Amie - 2021-01-25 1:48 AM
Quote
joval - 2021-01-25 5:03 AM
I don't use solder either...just a piece of foam tape on one end to compress battery against contacts.
That could be potentially dangerous if it ever wriggles lose. I wouldn't advise it.
Quite a number of websites
(
(recommending spot welders for example
) mention that the heat from soldering lithiun ion batteries can not uncommonly permanently damage the battery so as to render them susceptable to fire.
Of course you can tape down any wiggly wires...in the J720 battery there really is no wiggle room but care must be taken to maintain the proper location of such when closing the case. I think the MP900 batteries do have more wiggle room and might slip some...so tape or glue them down.
More importantly...do not forget the paper insulation washer that sits on the top the anode, as this prevents shorting to the surrounding case. And when pulling off the wire tabs using a screw driver or pocket knife
( I doubt a plastic credit card would work
) take care not to short the blade against the rim of the battery case. Only work on discharged batteries and charge them after rebuilding.
I just received an inexpensive $25 spot welder and after I add a protective capacitor to prevent undervoltage mosfet burn out
(so it can be used with smaller lead acid battery
) I will give it a try.
Again... don't forget the protective insulating "washer/ O-ring" on the anode
(+
side. My 2 centavos worth...
Incidently, it's also easy to open many failed laptop batteries using the above mentioned "hand wringing" approach. They sort of crack open like an egg. Leather gloves might provide an extra margin of safety from cuts, etc.
Joval
). Good info on the low temp solder paste-- Tin and Bismuth --- where do you get it? 
