Bosch 8AH battery NOT charging? Try This!

This Bosch Procore battery was not charging it was only showing 15.4v which is too low. The temptation to jump start something of this type of voltage is always there however it is always advisable to open it and test the banks of cells. I found upon testing the cells that indeed one bank which contains 2 21700 4000mah cells was completely dead showing no volts. The only solution was to replace the dead cells I proceeded to remove the dead cells and replace with similar. I was able to salvage 2 cells from a Parkside 8ah battery which had cells of the same type and output although the brand was different. I installed the cells with a battery spot welder and got the battery back charging and running tools again. The ProCORE 18V 8.0 Ah Professional is a high-performance battery that delivers the equivalent of up to 2,000 Watts of corded power. Its new generation cell technology, combined with intelligent battery management, delivers 87% more power than conventional batteries. The battery also features COOLPACK 2.0 technology for superior heat dissipation from the inside to the outside of the battery. As heat can damage the cells, this COOLPACK 2.0 technology provides an impressive 135% longer lifetime than standard batteries, enabling it to perform for longer work periods. Compatible with all tools and chargers of the Bosch Professional 18V System Parkside Performance 20V Smart Battery 8.0 Ah PAPS 208 A1 Li-Ion Battery EU for tools of the Parkside X 20V family Parkside 20V Battery 8,0Ah Li-Ion Battery EU for all tools of the Parkside X 20V Team Series Voltage: 20 V Capacity: 8.0 (Ah) ampere hours