1

I'd like to repair and re-use a small Bosch electric screwdriver. It currently has a battery of 3 small AA-type rechargables (unmarked cardboard wrapping) that has almost the same occupancy volume of a single 18650 Li-ion cell. The existing battery pack has an inline diode between the charging contacts and the battery pack.

I know about the risks as shown in Replacing NiMH with Li ion.

My key question: I want to re-use the two contacts on the base of the scredriver that connect to the battery for recharging. I have an existing external Li-ion charger (so not use the dumb AC brick that came with the drill). Should I (a) use or (b) explicitly not use a diode between the contacts and the cell for short-circuit protection?

Without a diode, I have a small risk of short circuit if something touches both contacts (small, because the contacts are recessed). With a diode I have a voltage drop that can interfere with the voltage sense of my charger.

I'd prefer not to throw away this otherwise perfectly functional screwdriver, and I'm not sure where to buy the same kind of NiMH battery pack.

KevinM
  • 119
  • 2
  • 2
    This will be neither safe nor effective – Chris Stratton Aug 21 '19 at 08:03
  • No, my question is about using or not using an inline diode for short circuit protection. I'm asking about using a single Li-ion cell (so the safety risks are reduced) and using an external charger. I believe my question is not a duplicate. – KevinM Aug 21 '19 at 08:18
  • Please explain why you think it will not be effective? What's the problem? – KevinM Aug 21 '19 at 08:19
  • If you're going to change the battery type you should remove or block off those contacts to make sure nobody ever uses the original charger and risks fire or explosion. – Finbarr Aug 21 '19 at 11:37

0 Answers0