Pocket PC problem - due to Empower?

I have a 6 year old HP Jornada 548 Pocket PC I've used daily since I bought it. After the last flight where I was plugged in to an Empower socket/HP car adapter, it seems to be running down quite quickly (2 hours instead of more than 5). It has a Li-Ion battery.

Is this a side effect of using it with Empower, or just a coincidence? After all, it's old, but I don't want to use my backup 548 (or, worse, my 568) and wreck them too. I hate to go without them at all, since I have about 5gb of CF cards with music, ebooks, and Word docs I carry with me.

If I have to go back to hefting a laptop, my back will go on strike. Since HP no longer makes the Jornada, buying a new one is not an option, and batteries on eBay are pretty long in the tooth as well. I've tried deep discharging the battery, but it didn't make much difference. If there's nothing to be done, would using this unit with Empower further damage the battery? HP says they really don't know what went wrong (since they no longer make this item), but what they do know is if I used an HP OEM car charger, the damage shouldn't have happened, especially if the fuse didn't blow.

Any thoughts?

TIA, vs_itsallgood

Originally posted by vs_itsallgood
I have a 6 year old HP Jornada 548 Pocket PC I've used daily since I bought it. After the last flight where I was plugged in to an Empower socket/HP car adapter, it seems to be running down quite quickly (2 hours instead of more than 5). It has a Li-Ion battery.

Is this a side effect of using it with Empower, or just a coincidence?

I'm assuming you connected an Empower to cigarette lighter socket into the seat, and then the HP car adaptor into that.

It's been a few years since I reverse engineered the Empower devices, but as I remember it consists of two wires for the power and two to tell it the voltage (internally ISTR there's a different resistor for different voltages).

For a cigarette lighter it'll be set for 12 volts.

Then your HP adaptor drops the voltage further for your device - say 5 volts or whatever it is.

Without having the devices here I can't tell you what's wrong, but you could test the HP adapter with a cheap voltmeter from your local RadioShack.

To test the Empower adapter you need a plane too ;-)

Did you notice the device getting particularly warm when you used it?

Lithium batteries are notoriously picky devices for charging but that should be hidden from the consumer. It might even be the charging circuit within the Journada that's gone South.

Notmally I would expect there to be a gradual failure rather than an immediate degradation, unless, as you suggest, something else is wrong.

FWIW I've used Empower for many years without any problems, other than the odd completely non-working socket in my seat, or it not being switched on.

I'm sorry I can't give you a panacea on this one, but maybe there are some pointers that may be of use.

Still, you are to be congratulated for getting six years use out of such a device: that's pretty darned good going in my book.

Cheres, Howard

Originally posted by Howard Long
Did you notice the device getting particularly warm when you used it?

Lithium batteries are notoriously picky devices for charging but that should be hidden from the consumer. It might even be the charging circuit within the Journada that's gone South.

Notmally I would expect there to be a gradual failure rather than an immediate degradation, unless, as you suggest, something else is wrong.

Still, you are to be congratulated for getting six years use out of such a device: that's pretty darned good going in my book.

Cheres, Howard

Yes, it's gotten hotter than usual, and I thought the Empower had started that. No, it hadn't! My travel charger went south, and seems to have taken the internal charger with it. That Radio Shack WAS able to confirm, as well as a Jornada repair guy I called. Well, eBay fixed the charger problem (my original one's still A-ok), and since I now know it wasn't the Empower, I'll save this one for in-flight.

As far as getting it to work all this time, well, it must be the Scots in me. I have a Chevy truck with 340,000 miles on the original engine, and the original transmission! Not gentle miles, either; it's been coast-to-coast and past both N+S borders to dog + horse shows, and the 'occasional' non-flight vacation, loaded to the gills with two-feets and four-feets. I really want a hybrid, but I just won't get rid of anything until it's worn totally out (which is why I won't get rid of my J just yet [:I]). But I've seen that T-mobile unit up close and personal, and it looked so nice in action, like that Lexus hybrid... wonder how long it would take to get dog slobber, a cat scratch, or horse manure on both of them?

Thanks for the help!