Calc wars

From: Joe <rigdonj_at_intellistar.net>
Date: Fri Mar 6 07:41:07 1998

At 08:11 PM 3/5/98 +0000, you wrote:
>> The battery pack is just two NiCad AA's welded to a set of contacts. It's
>> very easy to fix this on your own - if you don't have a spot-welder
>> in your household, solder will do after you roughen up the battery contact
>> surfaces. (In the past decade I've gone through
>> a HP15C and a HP41, but it's the HP25 that I still prefer...)
>
>All my HP20-series machines (woodstocks) have a metal spring in the
>battery pack that presses the cells against the terminals in the
>calculator. It will also connect a pair of normal AA cells together
>without needing to spot-weld or solder them.

  I just rebuilt two of them yesterday. Here's a few comments.

  They're a lot more reliable if you put a strap across them. The
spring/battery joint gets just enough corrision to make it intermitant.
Particurly troublesome on the C models.

>
>You can open up the battery pack, extract the old cells and fit some new
>AA NiCds in their place. Take care to get them the right way round, of
>course - at least one of my packs has the polarities moulded into the
>case, though.

   They all do. The markings are on the inside though.
>
>Don't use normal AA primary cells. These machines are designed to run at
>2.5V, and a 3V battery pack can cause damage. Yes, that is the voice of
>experience.

  Yeap, that's CMOS for you. Besides non-rechargeable batteries won't last
anytime at all in calcs with LED display.

  Joe
>
>
>>
>> Tim.
>>
>
>-tony
>
>
Received on Fri Mar 06 1998 - 07:41:07 GMT