patfla

Hi,

Have an x50v. And packed with all kinds of stuff, so that, if I wish, I can sometimes use it hrs on end.

Making my first very long plane flight with it. San Francisco to SE Asia. 9 hrs to Tokyo (hmm there may be somewhere in the business lounge in Narita where I can plug it in and recharge). And then 6 hrs to Singapore.

I have an larger capacity battery in it now (the single charge running time on the original battery was pretty poor). I forget (and can't find) the rating at the moment, but computing off the time and percentage left, I think that a single full charge on this large capacity battery yields about 4-and-a-hlf hrs. And I still have my original 1000 mAh (or was it 1100?). Which I need to look around for and find again ...

I have battery packs (mostly non-rechargeable [that is, standard AA alkalines]) for both my iPod and my Palm Tungsten (which I've largely given up on).

What do people recommend along these lines for an x50v?

I've looked what are for me the usual places (searching here and, say, www.pdaparts.com) and I'm surprised at how little I find.

There are many more such battery packs or whatever for, say, an iPod. But then iPods have to be a much bigger market than Axims.

pat

weastman

go to Amazon and type in "battery extender". Google can yield results as well. In any case, the term for what you are looking for is "battery extender". Also, there are some do it yourself threads for this on this site.

Pocketbrain

There are a bunch of home-made packs floating around Aximsite's forums.
Check out this post...
http://www.aximsite.com/boards/showp...3&postcount=32

__________________
The plural of Wii is Wiii.

boot up. log on. drop out.

THE REVOLUTION WILL BE SYNTHESIZED

timepilot84

Originally Posted by PocketBrain

There are a bunch of home-made packs floating around Aximsite's forums.

I've made a charger with a 7805 before, but pulling 2A through it with my Axim X51v causes it to get super hot. With 6 alkaline batteries you're burning off 2+ Watts. I'm currently (pun intended <snort>) working on a small form factor power supply with a switching regulator. I've seen small ones for sale on the InterWebs.

patfla

Ah. Amazon.

http://www.amazon.com/gp/product/B00...080007?ie=UTF8

Is the connector on the bottom of the device the same on the x50
as the x51 (I would expect to be, but of course want to check
first).

thanx. pat

Pocketbrain

Originally Posted by timepilot84

I've made a charger with a 7805 before, but pulling 2A through it with my Axim X51v causes it to get super hot. With 6 alkaline batteries you're burning off 2+ Watts. I'm currently (pun intended <snort>) working on a small form factor power supply with a switching regulator. I've seen small ones for sale on the InterWebs.

Not using Alkaline, NiMH only, unless in case of emergency, then I think I'll shut down the Ax to recharge, so as not to burn out my 7805. I already did that with the scorpion.
I'm working on a switcher, too, doing it with discrete components and some simple IC's.
Going to put a USB port on the battery pack, so I can keep my GPS bug alive on treks.

__________________
The plural of Wii is Wiii.

boot up. log on. drop out.

THE REVOLUTION WILL BE SYNTHESIZED

patfla

I called Dell.

The electrical (cradle/whatever) connectors on the bottom of the x50 and x51 are identical.

And so, out of curiousity, I asked: what anyway is the difference betwen the x50 and x51 (the numbers being so close together, I would assume the two models have only minor differences).

It seems that only the x51 will run Windows Mobile 2005 (mine came installed with Pocket PC 2003 2nd edition).

He wasn't able though to tell me what that 'really meant'.

I assume it means more internal memory?

pat

Pocketbrain

There is more "internal memory" in the X51, about 128MB more. Since some of WM05 sits in the ROM, and the rest is replicated in ROM, it doubles the basic install usage of ROM. The X51 series also uses no lead in its solder. I am sure there are other differences, but none know what they are.

__________________
The plural of Wii is Wiii.

boot up. log on. drop out.

THE REVOLUTION WILL BE SYNTHESIZED

timepilot84

Originally Posted by PocketBrain

I am sure there are other differences, but none know what they are.

There must have been some differences in the power management system in the X51v because you can set it to turn off completely, something not possible with wm5 on the X50v. I had an X50v and the thing was constantly firing off the high-priority filesystem clean up thread, which meant the device was pretty much unusable for 10+ minutes. Truly annoying. I think that was because it didn't have as much memory, though. How the new non-volatile fs works, is that instead of erasing memory and re-writing it when things are updated, it merely invalidates the old data and write to new areas. When you reach a point, the garbage collector thread fires up and cleans all the invalid memory locations. When you reach another critical point, the high priority version of this thread fires up. Because the X51v has more memory available, the high-priority thread doesn't get fired up like it did on the X50v.

I've been able to use all the external devices/batteries I had with the X50v with no issues. The interfaces appear to be identical.

timepilot84

Originally Posted by PocketBrain

Not using Alkaline, NiMH only, unless in case of emergency, then I think I'll shut down the Ax to recharge, so as not to burn out my 7805.

The 7805 has built in thermal shut-off. Even NiMH, with 6 batteries is 7.2v. The Axim is pulling 1A(the power supply says 2.2A, but the 7805 only provides 1A).

7.2v-5v=2.2v
2.2v.*1A = 2.2 Watts of heat burned off.

Put a big heat sink on it.

If you used Alkaline, it's 4 Watts burned off.

Using a switching regulator, you can limit the burn-off per volt to around 300-400 milliWatts, and can lower the drop-out voltage to the point where you could use 5 batteries (6v) instead of 6 batteries.

I saw one company on line selling fully made switching regulators for $16. I'll have to find the link and post it.

stevenator65

Patfla, let us know what you choose, how it performed, and have a safe trip.

Pocketbrain

Originally Posted by timepilot84

The 7805 has built in thermal shut-off. Even NiMH, with 6 batteries is 7.2v. The Axim is pulling 1A(the power supply says 2.2A, but the 7805 only provides 1A). 7.2v-5v=2.2v 2.2v.*1A = 2.2 Watts of heat burned off. Put a big heat sink on it. If you used Alkaline, it's 4 Watts burned off. Using a switching regulator, you can limit the burn-off per volt to around 300-400 milliWatts, and can lower the drop-out voltage to the point where you could use 5 batteries (6v) instead of 6 batteries. I saw one company on line selling fully made switching regulators for $16. I'll have to find the link and post it.

I have recharged from a very low (<10%) 3300mAH battery, and the load was sufficient to drop the output enough to cause flickering. The 7805 is heat-sinked to the case (thermal cmpd and tightly screwed on). With a good thermal sink, you can push a fair amt. of current through a 7805 without much problem. I did manage to burn out my scorpion, which was double-sinked, but that was a severe stress-test in which I was operating from a flat 3300 battery, from a 12V source. Ouch!
Right now, wit a linear reg, it might make sense to drop to 5 batteries, but with a switcher, you're gonna be using the extra capacity, so 6 batteries will actually last ~20% longer than 5.
Oh, and you're looking at ~1.4V per cell at full charge for NiMH.
I'm gonna breadboard something if I get the time, but that switch you brought up looks interesting.
(X)
.

timepilot84

Originally Posted by PocketBrain

I'm gonna breadboard something if I get the time, but that switch you brought up looks interesting. (X) .

I found this design for a 5v switching regulator that looks pretty clean.

http://www.interq.or.jp/japan/se-inoue/e_ckt22.htm

patfla

Originally Posted by stevenator65

Patfla, let us know what you choose, how it performed, and have a safe trip.

I bought the Gomadic 4-AA charger from off of Amazon for 19.95 and have had it more than a week I think.

So far, as best I can tell it's not working. I've been exchanging emails with someone at Gomadic but I'll get to that in a minute.

Strange symptomology. Put 4 new AAs into charger; attach charger to x50v; turn on charger. Red (on) light on charger goes on. Power button on x50v turns orange (which normally means charging). It was at 60%. I left it there maybe 45 minutes; came back and it was still at 60%. Recycled the Dell (push in button on back) to see if that's necessary to get a correct battery reading (as is the case with my gen 3 iPod). After rebooting, it still reported 60%. Huh what's going on?

Repeated the test several times all with the same result. And the last of those times, to make sure I had plenty of charge capactiy, put in 4 Energizer e(sqrd) AAs which are rated at 3000 mAh.

Still the same result. Red light goes on on charger; power button goes orange; leave for an hr and come back to find that the reported charge has not increased.

I always fully disconnect the charger between tests (and there have been nothing but tests so far but it's still far from clear to me that the charger is having any effect at all).

One of the more recent tests thought to check one thing more. The Battery applet - is the green bar at the top pulsing from left-to-right (indicating charging) and does it also say CHARGING? No it doesn't.

I've had two rounds of exchanges with someone at Gomadic. Here's his (or her) more recent reply.

Quote:

There is one more piece of information you should know about the Dell Axim Family of devices. You will find this information all over the AximSite and is a well known fact. This Axim design flaw bellow is a problem with low power chargers and is a limitation when the charger is 500ma (for example when charging from a USB port) or lower and also in the case with AA battery chargers. All after market chargers will exhibit the same symptoms. Our 1000mA charger do not exhibit this problem because with higher current output you will see less voltage drop in the power source. The Dell Axim Power is a little different than other mobile devices. Most PDA's require 5.0 volts of DC current to power and recharge the device. The Dell Axim, however, is slightly different. The Axim requires 5.4 volts of power which is slightly higher than all other mobile devices. Since electrically there is a +/- 10% buffer and will charge the device. We have noticed that once the Dell Axim gets below a certain base of battery life (ie. 30-40%) the charging system on the dell axim is more finicky. This is one design flaw of the Dell Axim. The extended battery charger will still keep your PDA going, but since the PDA uses more power than the charger can output ( miliamp hours [mAh]) it will still extend the battery life of the PDA. How to over come this limitation ... a) When the device is low in power try and turn off the device and let the charging circuit catch up. b) if you need to use the device try turning off WiFi, put the CPU in power save mode, and/or turn down the screen brightness Gomadic understands that these limitations may be unacceptable to some customers and as such, we are offering a full 100% refund to our customers. If you would like to receive a refund, please return your cable to the following address: ...

So the author (at Gomadic) says this is a well-known problem. I've only started to look around here on the www.aximsite.com forums, but have yet to find descriptions of the problem.

And if anyone can explain the problem better to me than what's quoted above, that would be very helpful.

pat

patfla

Now that I look around a little more (here on the forums), yes, there are many posts on issues relating to charging an x50v.

It's just a matter of sorting them out.

Would still, though, appreciate hearing back from anyone who can suggest specifics.

pat