Jornada 820 replacement battery

Hi!

I've been wanting to use my Jornada 820 outside for a while now, but the battery is a tad worn out. (And by that I mean it discharges at a rate of 1% per 2 seconds, giving me a total of 200 seconds runtime on one charge)
So I've been considering getting one of these on eBay
http://www.ebay.at/itm/950mAh-Battery-For-Jornada-820-928-Series-In...
(there are others, but they all seem to be the same chinese battery type). Does anyone have experience with those? are they safe to use and easy to install?

thanks!

That's a mistake...I don't know why it is everywhere. That is the replacement battery for the old Ipaq phone, not the Jornada 820 you are using...

They're still including the 820 in that listing? Uh, the 928 was a Pocket PC phone - not nearly the same battery.

The page below has been up for a long time, but maybe they're still around and can still do it:

http://www.batteryrebuild.com/laptops/hp/F1260-80068.phtml?gclid=CN...

Ok, I already wondered since I expected the guts of this battery to look different. Sadly the site you linked is U.S. only, as so many things are. :/

Anyway, thanks for clearing that up, I almost would've bought the wrong battery there!

Best bet is a simple battery rebuild using new cells, but now I see that they are not standard 18650s...ugh.

Are there any resources for DIY? I do lots of stuff with microcontrollers and have some experience with electronics, but Li-Ion batteries are scary

We came close to another solution here:

http://www.hpcfactor.com/forums/forums/thread-view.asp?tid=9927&sta...

- but hit a dead end.

A few places still claim to have them available...

http://www.pchub.com/uph/laptop/417-25275-286/HP-Jornada-820-Z-Batt...

and eBay of course...

http://www.ebay.com/itm/F1260-80068-Hewlett-packard-HP-Battery-Pack...

Why not recell them?

Well, is there any place where I can order the exact cells? I assume if I can order those, it'd be not to hard to do it myself

The thread linked in my last post was about that very subject.

Cell names contain their dimensions: 18650 cylinder has 18mm diameter and length of 65mm, it is the standard notebook cell.

If you have dead battery just take it apart and measure the things.

EDIT: I have read that thread. Did you search for smaller cells because of how rare these ones are? I got that. 5,7V instead of 7,7V after recelling. Did he balance them? I mean connect + to + and - to - through the resistor.

Edited by Alt Bass 2014-10-12 6:58 PM

There is Pete saying that PCB will detect cell failure and disconnect everything forever.

One may try to connect another source of 7,2V for the time of soldering so that PCB does not detect the open circuit.

Edited by Alt Bass 2014-10-12 7:04 PM

The idea behind individual battery cell protection is that by blowing the fuse on the PCB, it opens the circuit, preventing the other battery from exploding from voltage overload. If this happens, it can normally be jumped over the open, however then your battery is unprotected from overload the next time one of the individual cells fails.

I'm for all rebuilding any battery pack when there is no other choice...but I'm also for just buying a replacement if it is possible. My Skeyepad SL has been working great for over a year now with my homebuilt cells.

So one may try to connect a backup power for the time of resoldering.

If I had samples, I could do it for sure, but I live overseas.

Edited by Alt Bass 2014-10-12 7:54 PM