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Geoff Quickfall · 09-13-2014, 03:53 PM

Hi!

Okay, tapping the +ve end to reduce the length may not be a good idea due to exploding or leaking batteries, however, this is strictly anecdotal from personal experience over 8 years. I have done this for my 34c and never had a problem. That is a personal experience only; and maybe I have been lucky. :-)

The only problem I have ever had is with a specific brand that makes their battery so oversized, to extend their operational life by jamming as much chemical in to them, they have ruptured inside my maglite. They went in easily but expanded as they aged over a month. I find the generic house brands. (London Drugs, Walgreens, radio shack...) do not have the oversized cases in diameter and have never suffered from leaks even when tapped. Yes they are capped ends but I am deforming the nipple inwards, not the entire end. I have never had that problem with the tapped brand.

A triple a battery bracket is just too large (radio shack and generic local electronics shop) to fit that I have found, that is not to say there is one out there. And the problem is associated with the metal bracket used to hold the oversized batteries. The batteries are fine if the end is bridged by a piece of tin foil as mentioned above and the metal bracket is not used. Again the generic brands are usually smaller.

So tap them, and beware, insert them without a bracket or try and find a aaa holder that will fit and solder jumpers to the bracket. The book mentions all this, the owner of this calc wanted the ability to have it restored to close to original. Hence using the AAs and replace the battery tabs.

In fact, I have a 34c with the battery bracket entirely removed, a aa rechargeable pack form a phone installed and connected with a male and female phone battery connection plug for ease of replacement with one end soldered correctly to the board. I use an old phone to charge the battery as I don't trust the charging circuits on HP calcs, especially the woodstocks. The bracket is removed to allow the wire harness a place to hide with the pack in place.

So if you are using AAs in a spice with the original tabs installed, the caveat is, they are longer then HP designed for, especially if you intend to use the original metal bracket. This will result in broken tabs, cracked case corners or broken battery bracket.

Cheers, Geoff