Milwaukee M12 Battery Rebuild

How to rebuild Milwaukee 12v lithium battery?
Steps by steps:
1) First, open the battery cover and take out the battery
2) Use a multimeter to identify bad battery cell
3) Take out the bad battery cell and prepare a new 18650 battery
4) If you need a total battery pack rebuild, take out all old batteries
5) Use a spot welder to connect the batteries together
6) Measure C1- and C3+ terminal of the Milwaukee M12 battery, in normal case, the output voltage should be around 12V
7) Insert the batteries back to the battery cover, test the new milwaukee m12 battery rebuilt on the milwaukee m12 tool

[@crazgreek]

Which welder are you using? I bought one off amazon but it just doesnt have enough juice to make a good solid spot weld

[@sairus6055]

280 mOhm 3 battery in series? Do you find new cells in garbage bin? Power tools need hi current 18650 with typical internal resistance 12-15 mOhm. What the point make crappy stuff?

[@BananerRepublic]

Which batteries did you use... 18650 but what amperage ?

[@crazgreek]

Most good power tools use the Samsung 25r