Single CR123 based "Emergency" Cell Phone Charger.

Anyone try single AA based Emergency Cell Phone Chargers before? They don't work well at all, as a single AA cell just doesn't have enough capacity. The single AA chargers just don't have the current to charge more power hungry phones like Blackberries and Pocket PC's. (and probably not the iPhone either)

I have an HTC Touch Pocket PC (have used Pocket PC phones for awhile now), and I haven't found a single compact single cell charger that works well at all.

Basically something like this:

(Moderator note: Hot linked pic removed IAW CPF Rules.)

But with a single CR123, instead.

It would be a far easier converter since most cellphones operate on 3.7V batteries.

I think this would be a perfect project since it's almost flashlight like, with an aluminum tube and tail cap.

I'm thinking a small sandwich pill could fit in nicely. They key would be if there is any safety issue with this charger needeing to somehow sense the battery in the cellphone being full and shutting off. Although, I'm pretty sure most cellphone wallwart chargers are "dumb" chargers, and all the "smarts" are actually in the Cell phones themselves, or the battery itself.

What do you think?

-Ed

ive tried the AA one, but with a Lithium Cell, i did kind of find it useful cos it happened to be in my bag, and my phone was going out, just when i really needed it.

My main issue was that it got reeeealllly hot.

I think for flashaholics, it would be useful to have an Li-on version, maybe ill try 14500s in there, i mean, even if it fries the circuit, ill have direct drive right?

Crenshaw

Yeah, the regulator boosting from 1.5V to 3.7V is probably why it gets so hot.

-Ed

I've seen two cell AA ones. That should work with a 123.

Yeah, but two AA packs are large. I would like a small converter pill that would be the diameter of a CR123 cell, so it could be used in a tube like the single AA charger I have pictured above.

-Ed

Funny thing is the prospect of no electricity actually excites most Flashaholics, but cell phone use is another matter. My parents live in a further north area that was hit by the tip of the Hurricane, and it knocked out power to 90% of the city. Power has been restored to main areas of the city, but their home still has no power. They have no way of charging their cell phones other than in areas that have power (my dad works at a University, and they have their own power back up).

I could think of no better back up than a reliable CR123 based emergency charger. We stock up so much on CR123 primaries here.

Just thought of it again.

It's time for me to finish my own personal lighting projects, though, LOL, I've really been putting them off. Need to buy a few Sharks soon. Heheh.

Yeah, economy sucks, but I don't want to be in the dark.

Man, I wish I had a regular job and didn't do anything when I get home except work on my hobby related projects. I could realistically prioritize which hobby project I could work on and generate a realistic schedule of when it might get completed.

I can't even get to my todo list as I seem to be like a light switch either totally off or going bat out of hell mode. Currently I'm latter.

As much as I would like to work on this project I am overloaded at the moment. Since June I've not been doing too many projects as I've been putting all my time in learning how to operate the CNC machine I bought from Jonathan.

The push is on to try to get stuff into production real soon so that I can hopefully catch any xmas wave of sales.

I can generate small spots of time between and during my schedule especially if someone was generating most of the research and can put forth the ideas or designs where I could just implement them and test them. Spending time researching and looking for components takes a long time.

Also, one less motivator for me is I have a new phone. So, some of issues I was starting to get into with a dying battery is now erased with the new phone.

Wayne

This whole thing is so crazy. I just wish they would make cell phones that ran on AA's directly. I started another thread in Wayne's forum about making a converter, so I'll say here that I'm still interested.

Meanwhile, as for emergency chargers, I'd just use a 2AA-based charger and stick a 123 in it if that's what you want to do. But why not just use AA's?

Anyway, here is a DIY 2aa charger, or the designer will sell you a complete kit:

http://ladyada.net/make/mintyboost/

It should be easy to adapt to use a 123

I wanted a compact and reliable solution. I carry lots of CR123A's with me, not AA's, because I EDC flashlights that use them.

-Ed

Edwood, that Mintyboost thing is in an altoids case for use with two AA's, but you could use the same circuit in a smaller case with a 123. One of those tubular match cases might be a good choice, since it is very waterproof.

I tried the single AA unit with a Nimh and it didn't work worth a darn on my Nokia.

The energizer 2xAA one that I tried had internal measurements such that only the Lithium batteries fit correctly. The Nimh I tried had button tops that were too short to make a connection.

I think a buck circuit would be better than a boost so I'd like to see a small 2xCR123 unit that could also take 17670s and 18650's.

Would a direct connect (no circuit) 18650 work?