How to Charge a Dead Battery

I was hacking at the space last week. I had brought my old Nikon D1X along, wanting to take some photos, but the battery was dead! I didn’t have the charger at the space, so what’s a guy to do?Charging a Dead Battery


I did have a variable power supply with a current meter available to me, so I devised a solution. Using a voltmeter, I figured out which was the positive and the negative terminal, then I hooked that up to the power supply. I adjusted the power supply so it read .9A, and waited. I noticed that after 10 minutes or so, that had dropped to .7A, so I turned the voltage up a bit. 10 minutes later, same thing. 10 minutes later I disconnected the battery, and it was charged!

Some notes:

  • Battery’s rating: 7.5v
  • Initial charge: 7.2v
  • Final charge: 7.9v