And I opened the pack up, and you are 100% right! It's just a plastic shell containing 10 big C-size cells, 3.5 A.hr each, indeed from the time period it must be NiCd! Now if I can find similar cells I will be able to reconstruct the pack inside the same shell. It will even look like the original. Thanks again. Marc ------------------------------ "J. David Bryan" <jdbryan at acm.org> said That marks it as an "A-version" power supply. Note that the "A" supply used a 12 Volt nickel-cadmium battery pack (per page IXA-1 of the M/E/F-Series ERD), and the charger is a constant-current supply. The pack is not broken down in the parts list but presumably would have contained ten 1.2-Volt cells. The "B" supply used a 14 Volt lead-acid battery pack (ERD IXB-5), so seven 2.0-Volt cells, and the charger is a constant-voltage supply. If you use lead-acid batteries with the "A" power supply, you may wind up overcharging them and shortening their life. -- Dave ------------------------------