This video describes what you can do if your battery goes bad how the jump Start method of recovery works and why sometimes it doesn't.
These 2 18v 2ah bosch batteries were in a suboptimal condition to say the least reading less than 2v which is not ideal for an 18v battery.
I elected to use the jump Start method of recovery monitoring the voltage and explain how it works.
Disclaimer
battery repair is a risky undertaking and careful consideration should be taken before attempting It is not the intention of Doctor Lefthandthread media for any injury to occur as a result of my videos