I made a battery case for 4 AA cell batteries and connected it to a mini USB cable. I used it to power the phone to listen to some music and noticed that the battery case and the cable got rather warm during use!!!???

Last night I was on the phone for about 30 minutes while it was on the wall charger and noticed that the battery got really warm!

Are these indications of problems with the phone or does everyones' phone get hot when you use it?

Thanks

im saying that scares me some time i think we need cpu coolers imagine? Nah but seriously it gets really warm down under the keyboard

You shouldn't do that for two reasons. First off, the device will draw at least .5 amps, which is considerably more than 4 AAs should be asked to provide. Secondly, you're sending 6+ volts to a pin that's expecting 5v. While there may not be any immediate problems, long term use in that configuration might result in damage to the phone's voltage regulators.

You'd get a lot more power out of less physical space by using the Seidio extended battery.
You're pulling more current than the batteries and connecting wire can handle. While it's OK for the phone's battery to warm up (it's a normal trait of lithium ion batteries), alkaline cells heating up can be a precursor to them exploding. I'd highly suggest discontinuing this and getting an extended battery if you need more power.

I don't understand why you are going to so much trouble when you could just plug into your vest socket.

http://www.scottevest.com/pressrelea...lar/index.html

Kurt

I thought that the charging of the phone could go up to .5 amps and that was usually supplied by the wall charger. Also, the cable I used was from a usb to mini-usb that would charge the phone from the laptop without any extra heat.

Others have reported on this forum that they have been able to charge their batteries using this type of setup, so I am confused as to the heat issue.

I do plan to change the setup to limit the voltage to 5 volts to see if that helps any.

The reason I did this was to provide some extra time to watch vidios or to listen to music when away from the car or the house. So far I have invested less than $7.00 in the entire project.

Have you tried a good set of NiMH in your pack? The Energizer 2500mAh put out 1.4V peak, so your fully charged charge pack will max out at around 5.6V... somewhat closer to the 5V target. Voltage drops as you pull juice from the cells... they reach 1.25V after about one hour of sustained .5Amp pull. These cells can provide .5Amps sustained for 5 hours... they should more than do the trick. Also, the batteries can handle a 2Amp sustained load, so you won't be running them harder than they are made to run. I do suggest a voltage regulator of some sort be installed in your pack, even if you are using lower voltage cells.

If you want to review the actual cell characteristics for yourself, there is a PDF downloadable from Energizer's website. http://data.energizer.com/SearchResult.aspx

Ishkabibble2

I agree with your suggestion for anyone who wants to go to the trouble of an external AA pack. I wouldn't do that but if I did, I'd use the NiMH cells. Also, I didn't know that these cells would hold the peak 1.4v for an hour. My background has been with NiCad's and these have the same voltage characteristics but do drop off in a few minutes to 1.2v. This would get you 4.8 V to 5 volts which would be perfect in this application.

But at the end of the day, I really agree with the suggestion to use a higher capacity pack designed for the phone. I have two std size that I swap out but keep a 3rd battery, the UTStarcom extra duty one with cover handy for days when I know I'll have heavy use or need an 12-15 hour normal use.

Regarding the heat- Yes, I have noticed this when I turn on the wifi. It seems the battery is what gets warm. I have learned to use wifi for download big files such as podcasts and then shut it down when finished. EVDO surfs the web fine but big 70 Mb downloads are best done with wifi.

Thanks everyone, I will try the voltage regulator and see what happens. By the way, I am using 2300mAh NiCad batteries so they should be close to the 2500s in performance. If this works out, I will probably get some larger batteries.