Jornada 820 Battery

I haven't heard back from Gordon yet. I hope he doesn't think I'm just stringing him along - if we can figure out how to install them, he could be getting a lot of orders from us for those cells.

Hello all,
Has anyone had an experience of these chaps? I think this might just be a CMOS battery as £5.85 (about $12) sounds very cheap! I know most of you are in the states - but I thought I'd give it a try anyway.

http://www.mobile-phone-battery.co.uk/hp-jornada-728.htm

I have a contact in the States and I visit them quite regularly so if you are able to get some cells off this Gordon chap I'd be interested. Also has anyone thought about bolting some AAA sized Li-Ion cells together? Which can be got here:

http://www.ecrater.com/product.php?pid=168430 - these are 1100 mAH, 1.5V ones
or here http://www.onlybatteries.com/showitem.asp?ItemID=14670.11&cat1=27&uid=1106
or here http://batteryjunction.com/licyba181417.html (this maybe the best resource)

AAA sized cells will fit in the original battery casing. Can anyone think of any reason why this might not work?
Thanks
Tom

Li-Ion AAA cells are really 1.2V; you need three blocks of 6 of them in series to get to the 7.2V, 3.5Ah of the original battery. Can you get 18 of them in the original battery case?

I don't know about the link you sent; it says 728 rather than 820. I know one guy on eBay from Hong Kong regularly advertises a battery for the 820 and 928 that's really only for the 928.

I think I would use the battery junction source if I was to use AAA sized cells. The direct page is here:
http://batteryjunction.com/10440.html

These are 3.6v cells so I would probably use 6 lots of 2 in series thus giving me 7.2v and 6000mAH. What do you think?

Also the link to the uk based 820 battery supplier was wrong. I meant to put:
http://www.mobile-phone-battery.co.uk/battery-hp-jornada-820.htm

Tom

No word from Gordon as of this writing. Maybe he doesn't believe we want to buy.

Well, I disassembled my battery, and I have some tips for dissasmembly:

1. Slice sides, along seam.
2. Slice area between latches and batetry contact, where there is a seam.
3. Pry apart one side/corner, and then spread the seam along the back/top of the battery (with connector and inside top facing you) to separate it.
4. Using a plastic blade (You can fabricate one, doesnt have to be really sharp), slice/pry the batteries from the double sided tape holding them to the top.
5. With top off, use snippers to disconnect batteries, and place electrical tape over the terminals.
6. Finish removing batteries.

I'd have to say: When I order cells, I'll consider a pair of LARGE, 3.6v li-ion cells, with some free space... Could be significantly cheaper!
The cells are connected in 3 parallel, 2 series.

Pics coming soon- My camera may have bit the dust after a long battle with complications due to hit-it-so-it-works syndrome.

Added:
By my measurements, 4 of these bad boys will fill up your Jornada. http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=579

Make a pair of 2 parallel packs, each connected to a individual charge area. Ground the case to the common ground.

INfo on original cells:
TYPE..........V.....mAh..LENGTH..DIA/WIDTH.THICK.WEIGHT
US103463..3.6.. 1650......10...........34...........62.8.....58

So the original pack was 2s3p of 1650MAH, total of 7.2V at 4950mAh.
My replacement cells will equate to 2s2p of 2700MAH, total of 7.2V at 5200mAh.

Therefor, battery should charge well, and last a bit longer than the original, brand new, and be ALOT lighter!

Edited by Pete P. 2008-02-14 12:35 AM

Hope you haven't tried that remedy with the 820.

I'm looking forward to hearing your results, cuz if I don't hear from Gordon soon, your plan may be the best alternative available.

Edited by CE Geek 2008-02-14 12:28 AM

The CMOS sensor was loose- Jarring the camera meant it would work :-D

The battery was easy enough to assemble- My problem is getting the funds for the batteries!! :-P

What I'll prolly end up doing is recelling the battery, and then selling the prototype Jornada again, with it's brand new recelled prototype battery :-D

That is one cool 820 you have, Pete - wish I could afford to buy it. (I'm trying to improve my financial status to just "broke" at the moment. )

Can those cells be connected without soldering by any chance? Putting a soldering iron in my hand is like putting a six-year-old behind the wheel of a car: the only question is how much damage I'll do.

It could be made easy. Solder a good wire to the +1 +2 and GND (minimal soldering skills required) and then tape/conductive adhesive/wire-wrap the rest. Or leave it to a professional :-P

And I dont mean to sell the Jornada for much more than its worth, being that it's 100% unique, and professionally rebuilt :-P

Yes - I think you maybe onto something Pete. I might use 6 of these cells:

http://www.all-battery.com/index.asp?PageAction=VIEWPROD&ProdID=1561
It looks as though I could squeeze 6 into the battery case.

Would only give me 3900mAH but would only cost $40+tax and shipping (as opposed to $70 + tax + shipping with Pete's idea). If I'm feeling flash with cash I'll definitely go with Pete's idea though.

You need to at least match the original cells capacity, or you risk causing problems due to too high of a current being used to charge the cells.

My original battery has a capacity of 3.2Ah and my 6 celled design would have 3.9Ah. That would be enough wouldn't it (i.e it would survive the charge current)? Also - would the charge indicator on the Jornada be accurate - or does that part of the circuitry have to be calibrated to the cells?
Tom

Should calibrate properly. My original battery was ~5000mAh... my proto must have had a high cap battery :-P

Any update on rebuilding battery progress? I have a Jornada with a completely dead battery, no charge, no juice. I would like to rebuild it based on everyone's research.