+- HP Forums (https://www.hpmuseum.org/forum)
+-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html)
+--- Forum: General Forum (/forum-4.html)
+--- Thread: Woodstock Battery Contacts (/thread-15266.html)
Woodstock Battery Contacts - PANAMATIK - 06-27-2020 11:49 AM
I want to share an approach for renewing the battery contacs of Woodstock calculators like HP-25, HP-29C.
Often they are in very bad corroded condition. Therefore I tried to replace them. The old contacts must be removed by drilling with a 2.5 mm drill. They are made of nickel plated solid brass.
I inserted two 2.5x6 mm "round head rivets" with 2.7x6 mm brass washers. After removing some solder resists from the board I could solder the washers to the copper traces leading to the battery.
The final prototype
I made the washers a little bit smaller with a Dremel tool, you need to use AA flat top batteries. Ideally would have been 2.7x5mm washers, but I didn't find them. Even better if they would be gold plated. I bought some gold electrolyte and perhaps will make a try.
Bernhard
RE: Woodstock Battery Contacts - Bill Duncan - 06-27-2020 10:41 PM
Thank you!