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I recently acquired an HP28S in good condition except for one problem. It seems to be a design flaw making itself known. Anyhow, the battery springs push against the batteries and the battery cover causing it to bulge out. This leaves a palpable edge that makes it a difficult to close the cover without pushing on the battery door. Is there a workable fix for this?

This is the achilles heel of this design, and is absolutely the worst battery door design ever devised by HP. Eventually either the door breaks or the case breaks, leaving you with no way to keep it in place. Perhaps some other forum members can help with preventive measures or fixes, but my only advice is to pray.

Looking closer, it seems that the door is okay, but the case is starting to fail. If I could get the calculator open, then I think I could push on the springs to reduce their height a bit, then wedge a metal rod in there to keep the cells back. Then the door can be inserted and it won't stick out.

If nothing has chipped off yet, a bit of epoxy on the case should strengthen it enough.

I've gone through *three* $150 point and shoot cameras for essentially the same reason. You'd think someone would learn something...but some of us are slow on the uptake :-/

...something to keep in mind every time you hear someone complains about Apple products lack of removable batteries :-)

LOL >:<

I sense gospel from the Book of Jobs in the Apple religion. It's obvious that the money to be made by Apple servicing departments, or by the purchase of a new phone, is the only reason Apple batteries aren't accessible. The same pathological need for control prevented SD card support. Saint Steve apparently even disliked SIM card access, but that privilege was graciously granted by Apple-god.

The Clamshell door design is a yet another example of poor engineering by HP. It's failure is not a rational argument for Apple-Nazi-like customer control, any more than the failure of the Woodstock charging system is an argument against rechargeable batteries in any device.

Also the fact that 90% of forum members could and would change their own battery just for a chance to open a device up. Lol

Amen, Mike! ;)


You win the hyperbole award.

Haha absolutely!

"Saint Steve apparently even disliked SIM card access"

He wouldn't have sold a single phone in many countries round the world if he had not given simm access--that's how it works in the rest of the world. The "unlocked phone" is actually normal--the US phone-facsists have us brainwashed thinking it is not.

what's that old usenet saw about the 1st person to say the n word loses the argument by default?

I think it's Godwin's Law. Here's a link written by Mike Godwin.

That's hilarious. Tnx 4 lnk.

Has anyone here tried making a clip this the one shown in this link? http://www.mpshp.com/hp28s

The 28S is my personal favorite of all the HP's (well it was my first HP - I do have many other favorites now as well ...). I've found the best way to fix the battery door is to buy a new 28S!

HP did overcome this design flaw in the last version of the 19Bii - a back access battery door. This design came about well after production of the 28S ceased unfortunately. Cheers, Keith

Edited: 8 Feb 2012, 4:26 a.m.

Advising me to buy another 28s is not helpful... I want to find someone who can make one of those clips.

Hey David,

I'd be up for designing this in CAD and having my sheetmetal shop make some. Contact me directly if interested.


Someone has built one of them using a computer case slot insert. Hope it helps.

That would be me and there is more info here in this article -- skip to the bottom.

I would not say I did a very good job but at least it was simple and has the calculator functional again, if not esthetically pleasing.

The offer from Adam's metal shop is likely your best bet if you want a result more in keeping with the original source from the link you gave.

You'll note that I mentioned in the article that I thought that the springs were way too stiff and should be cut down to reduce the stress on the case.

Good luck David!

I've gone through *three* $150 point and shoot cameras for essentially the same reason. You'd think someone would learn something...but some of us are slow on the uptake :-/

Ha! That reminds me of my Olympus D-340R -- one of the nicer early digital cameras, took great pictures, and I took it with me wherever I went, until the LCD on the back stopped working after 10+ years... But nice as it was, the one thing that *always* ticked me off was the battery door. Having to apply 100 pounds of pressure on an area of 1 cm^2 while twisting a tiny recessed lever that also needs massive force but that you can only get purchase on with your fingernails... how does such a horrible design ever make it past QA? The irony being that Olympus is not a company that has a reputation for crappy products, and neither is (or, well, was) HP, and yet sometimes they produced these real stinkers. Oh, yes, the Woodstock battery situation... Or my 1991 VW Passat with its flaky electronics and a cooling system that could not keep the engine cool while also running the AC in stop-and-go traffic in 90 °F weather... It's the juxtaposition of *mostly* great products that then have these glaring flaws (that any halfway sane QA process would have caught) that is so weird, and so amusing. I guess it's also a bit endearing. My perfect Toyota is just a bit... well, *boring*, by comparison...

LOL on Toyota. I have 2 of them. My Corolla made 200k miles yesterday. I have replaced the driver's side door handle 3 times. Every 67ooo miles I put the 4th one (3rd replace) on a week ago.

Edited: 10 Feb 2012, 7:44 p.m.