I got a used DPD Discharger from my son. He has had it sitting for a long time. I put in new "AA" batteries.

I get an error message to check battery connection or not making contact. On 2 of my pack out of 10 it works correctly but the other 4 it doesn't. I don't believe that it's a battery bar issue between cells or a bad solder.

The external works fine either for 4 -4 cell packs or 6 -6 cell packs.

Any other suggestions?

I've had the same problem with some of my packs when they sat for a while. Try putting a little charge in the packs then put them on the DPD.

Thanks.

I'll try in the morning and see.