HP Forum Archive 12

[ Return to Index | Top of Index ]

Battery Corrosion in Classics Message #1 Posted by Steven Soto on 29 Apr 2003, 11:27 p.m. I hope this question hasn't already been done to death... I got my first classic recently, an HP45, and it works fine on a charger. I found a new battery pack at a local bookstore, but I think the spring contacts in the calculator are too corroded to make good contact and charge the pack. I have tried using sandpaper and a knife, but the corrosion is very stubborn and I do not want to hurt the contacts. Any other ideas? Will I need to replace the contacts? I don't want a Frankenclassic, but if that's the only option, so be it. The other question I have is regarding the battery pack. It has never been used. I bought it in the original packaging last week, but what I don't know is if the cells are still good after all of this time. Should I rebuild it, or address the contact problem first and then see if it will hold a charge? Thanks. -Steven

Re: Battery Corrosion in Classics Message #2 Posted by Katie on 30 Apr 2003, 12:05 a.m., in response to message #1 by Steven Soto I use super fine grain sand paper (1200) to clean off corrosion, but if it's really bad just try scraping it off with a knife first. But your problem may not be the battery contacts. There's a little spring metal plate that connects the outer 2 pins of the AC adapter jack together when running on batteries. This plate may not be making good contact and it needs to for the batteries to feed power to the circuit. As far as the new battery pack goes, if you have a voltmeter you should get some reading from it even if it has been sitting around for years. If it reads '0' it probably needs to be rebuilt with new cells.

Re: Battery Corrosion in Classics Message #3 Posted by David Smith on 30 Apr 2003, 11:27 a.m., in response to message #2 by Katie The classic battery packs make connection to the contacts along the curved EDGES at the top of the contacts (not the tops of the contacts). Make sure you get the edges cleaned off very well. To make sure the contacts are the problems (and not the charger bypass strap) connect the battery pack with clip leads. Clip them near the middle of the contacts and not the near the tips where corrosion can be very hard to see.

Re: Battery Corrosion in Classics Message #4 Posted by Steven Soto on 30 Apr 2003, 7:39 p.m., in response to message #3 by David Smith Thank you. The edges were worse off than the tops of the pads. Incidentally, the edges are easier to clean than the tops of the pads. I now have a perfectly working classic. No Frankenstein. -Steven

[ Return to Index | Top of Index ]

Go back to the main exhibit hall