USB Charging Cable Problem

[mmurdock]

I purchased a usb cable for my Axim that is supposed to charge my handheld. When I plug it in the Axim starts charging while looking at the battery meter it shows charging but the percent charged drops rapidly to about 17%. If I unplug the cable and soft restart the Axim the meter shows the original charge amount. I have the latest ROM and I've tried this on two different Axims with the same result. I also tried it on two different computers.


Thanks.

[trachy]

Sure sounds wierd. Are you sure the computers you're using have powered USB ports? Most are, but you never know.

[blazingwolf]

This happens because the Axim uses a slighlty higher amperage ( I think thats right) then most other PPC. Something like 5.4 instead of 5. It takes longer to charge the Axim but it does work. I had the same problem but it does not seem to affect anything in the unit. It will eventually be charged just like using the cradle.

[Sven Johannsen]

...slighlty higher amperage ...Something like 5.4 instead of 5.

I think you mean Volts on those numbers. 5 Amps could weld the AXIM to the cradle. To charge something you need a bit more voltage than what the device normally produces. If it is a 5 volt battery, you need better than 5 volts to charge it. You also need sufficient current capacity (the amps) to do it at a reasonable rate. The amount of current needed is a function of the difference in voltage and characteristics of the battery. If you try to draw too much current from the charging device (more than it is capable of) the voltage it provides drops. If it drops to the level of the device being charged, charging stops.

So, some USB ports do not have very well regulated supplies. That means their voltage drops if you put a heavy load on them, like trying to charge a PPC. Others are well regulated and will continue to supply current and hold their voltage up. Even in this case, the charging current may be significantly lower than what the normal power supply delivers and that means longer charge times.

On PPCs I normally look at the battery screen. If it says "charging", or whatever it normally says when the regular power supply is plugged in, then it is indeed charging. How fast is an experimental effort.

[mmurdock]

Thank you for your input.

Mat

[Hx4700]

I have the same problem as mmurdock. Percent goes way down in just a few minutes while charging indicator is on. then it usually bounces back to about 50 percent when I unplug it.
Ron...

[arglebargle]

I just got back from a long vacation in the UK where I planned I would use my laptop usb to charge both my axim and my wife's maestro and cut down on cables (and heavy transformers). I had the same problem with the axim where the battery charge indicator would drop very quickly while "charging". I noticed that when I unplugged it that the charge would bounce back up so I thought I'd be safe leaving it charging all night. Bad idea, in the morning it was completely drained and all data was lost. Argh.

My wife's maestro charged just fine.

Live and learn--ArgleBargle[/quote]

[blazingwolf]

I recently noticed that you can charge the Axim only if it is at 80% or higher charge. It will not work at anything lower. Also, while I was looking at the PocketPCTechs site. Their new charge/sync cable states the same thing. Not sure why it does this though.