|HP82143A Printer, HP82033A pack, HP 820XXX Charger|
Message #1 Posted by Guillermo Castarés on 4 June 1999, 6:19 p.m.
Few days ago I bought a HP82143A printer. It came with an old HP82033A battery pack, but without charger and without manuals. I measured the pack with a tester and it showed 0.00 Volts.
After I got some info, I took the risk of make a charger by myself. The transformer I used have this nominal values: 220V (the voltage here in Argentina), 9V AC. 500 mA. Connected without load it shows 10.0 V
Then I connected it to the printer (with the old pack inside) and when I measured the charger voltage, it showed about 3 V. ! I disconnected it, but maybe later. First question: Could it damage the printer ?
Then I took the old pack out and connected my charger again. With the printer OFF it measured 10.0 V AC, and the battery contacts measured 0 V. With the printer ON it measured ~8.5 V AC, and the battery contacts measured ~6.5 V DC. Second question: Is it Ok? Seems that it will not charge the battery if printer is OFF. Is this the normal condition or I damaged the printer?
After that, I decided to make a totally new pack. I made it with four new Ni-Cd 1700 mAh sub-C cells. Once my new pack was ready, it measured 4.8 volts without load.
I drop the new pack on the printer and tried a little printout. It worked Ok.
Then I connected my charger and turned the printer ON to charge the pack for the very first time. The charger measured 7.0 V. AC. I left it 8 hours and after that, the charger measured 6.5 V AC. I disconnected the charger, took the pack out of the printer, just to realize that it was really HOT (It was not possible to hold it firmly in your hand without get hurt ) . Part of the plastic cover of the cells was melted (I saw that original pack have paper cover instead of plastic cover). The pack measured now 5.11 V. without load. The printer worked still Ok on this battery pack. Third question: Is this high temperature normal ? Could this high temperature damage the cells? Or, What is wrong ?
As you can see, my knowledge about batteries, chargers and regulators is very limited. Anyway I guess the regulator was burned out when I connected the charger with the old pack, and then the damaged regulator couldn't operate properly with the new pack. What do you think ?
Thanks in advance, Guillermo Castarés.