AA Battery Phone Charger  


So, I had an idea. And this time I swear I'll follow through. I already ordered the parts.

The idea?

"AA Battery Phone Charger".

The main reason I want to do this is for the sake of making something, but I would use it while traveling, ie on long plane rides, or what have you.

Or, if you happen to be walking around the grand canyon, it could be useful to have a portable charging station to provide a fresh charge, or even more.

Design Requirements:

-Simple Design
-Easy to Reuse
-Treehugger friendly?

The system works like this:

Batteries -> DC-5V USB Converter -> Phone

Not complex by any means.

The parts I ordered, and are required:
- Four 8-Cell AA Battery Holders (12V ea.)
- 5-24V to 5V USB DC-DC Converter

There are multiple configurations that could be produced. Personally, I have a Galaxy Note 2, and the charger is 2 amperes. The battery generally charges in 2-3 hours.

Assuming a charging rate of 2000mA, and a nominal capacity of 2000mAh per cell, here are the ideal charging times that could be produced:

1 Pack @ 12V -1 Hour 40 Minutes
2 Packs @ 24V -3 Hours 20 Minutes
4 Packs @ 24V -6 Hours 40 Minutes

The 1 pack is the lightest however, and is probably the most relevant configuration. It would probably be good for an hour and 20 minutes, which can provide a decent charge. With 2 packs, it should be able to provide a complete or near complete charge.

Of course, the batteries would be drained, and you'd have to fork out more money for AA batteries. So this idea won't really work too well. I'd test it anyways , just to prove the concept.

Now, for the interesting bit..

- One option is AA NiMH batteries. It would cost 50 bucks for 16, but they would provide about 1400-2000mAh. So there you'd have a 1.4Ah 24V Battery...

- Another, is AA carbon zinc batteries. Dollar store sells these for dirt cheap, and you could get a large amount of them with ease. They wouldn't be able to last more than one charge, but they would get the job done with 4 packs.

What I'm really looking at though, is using some sort of lithium cell..

Option 1:

LC 16340 Ultra Fire Cells
3.7V 1000mAh. 6 in series gives 22.2V, so a reasonable setup would have 3 sets of 6 for 4.6 Hours, or 4 sets of 6 for 6 hours.

These are of course, rechargeable.

Option 2:
18650 Cells

They cost about 12 bucks, but you could use it for 15 and a half hours. Not bad. That's about 7.5 full charges,
and if you had a smaller phone, it would charge well over 15 times. Wouldn't have to think about it, assuming you don't use it that much. It would be handy to have, just in case.

I'm looking more towards Option 1, since it is rechargeable. Whats the point if you can't reuse it without ordering more batteries online? You'd have to build a charger, but that's not difficult.

Of course, there's the third option, which is a big, ugly, heavy, smelly, nasty, big LEAD ACID BATTERY.

But that defeats the purpose of having something portable and modern..

On Solar Panels

Solar panels are an interesting idea, but they wouldn't provide a 2 hour charge. You could hold it up to a plane window though, place it on a backpack, etc.

I really like the idea of getting a circular panel and putting it on a hat.. it's crazy but it might just work...

I'll figure that out later, but right now I want to focus on AA charging, and perhaps a lithium setup.

Any ideas/comments?

Posted : 13/09/2013 10:38 pm


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