HP-28S battery door

[burkhard]

(09-04-2018 07:30 PM)jonese Wrote:  Ideas on how do I can avoid the battery door issue?

I understand what Maximilian is saying with respect to tape and the batteries, but in order for that to work, they are going to be really hard to take out as well. It seems tough to achieve the "sweet spot" and difficult to extract the batteries when they need extracting.

I had considered (but haven't tried it yet) trying either a flat top N or possibly even a flat top 2/3 AAA instead of the normal N. The normal "N" battery should be slightly shorter (better) than a normal "2/3 AAA", but a flatop "2/3 AAA" might be slightly shorter (better) than the normal "N", helping to reduce the static loading of the door:body interface. I haven't confirmed the measurements yet, though.

In the interim, any time I need to open to battery compartment, I actually press the door in a little while I'm sliding it. This is a bit counter intuitive, but allow me to explain. While this compresses the springs a bit more, it stops the door from sliding against the case. That door:case sliding under pressure is bad news; it acts on the stress risers designed into the interface and allows cracks to start and propagate readily. Avoid the stress at the interface and things are a lot safer, IMO.

It sounds obvious, but DON'T drop it on the floor. One good hit there while the battery springs are pressing on everything and it's "Goodnight, Irene" as my uncle used to say. They can't handle the shock on top of the normal battery load.

It seems most HP calculator models have at least one crappy design aspect. This is it for the clamshells.

Good luck!