Build a 4 x AA USB Altoids Battery

Step 10 Updates & Observations.

UPDATE: 8-31-08

1) For those of you who want to charge your iPod with this, please read this supplementary Instructable. I figure you could wire those resistors into a short USB extension cable or something so they don't drain the battery.

2) If you're going to be using Lithium batteries, be sure to install a 1A Diode on the positive terminal so that there's no chance of electricity feeding back into the batteries. That would be bad.

3) You can use a 4xAA battery holder just fine, it may save you some trouble soldering together 4 individual battery holders.

Comments

[Linkiboy]

Would this be able to output 2A at 5V theoretically (disregarding the plug)? And if so, for how long?

[Sitnalta]

Theoretically, this will be able to supply 10 amps for 1 hour, or 2 amps for 5 hours. But there's no way a USB cable would be able to handle 2 amps.

[telfon]

Nope. Since the batteries are connected in series you cannot add the capacities together. One battery can provide (in optimum conditions) 2.5 amps for 1 hour at 1.2 volts. Four batteries connected in parallel can provide 10 amps for 1 hour at 1.2 volts. Four batteries connected in series, as they are in this project can provide 2.5 amps for 1 hour at 4.8 volts.

[Snipeye]

I have an iPod touch 1st Gen, I want to know if I can just make this (not the "supplimentary instructuble" you provided, and if that will charge my ipod. I was also wondering if it would be possible to add a usb cable on the back, so when you plugged in the charger, it would charge?

[Sitnalta]

I have an iTouch 2G, and it requires no resistors or anything, just straight 5V. So yes, it should.

[hhazelhorst]

Would this also work with the iPhone 3G? I read an article about connecting the USD datapins (the middle ones) with resistors to the + which resembles your description. I'd like to try out, anyone did this with an iPhone 3G? HE

[pablosartor]

i have a 3g works fine. Anyone know how to incorporate a charger so i can charge the batts over the usb hub.

[bmmp]

hey pablo, Which batteries did you use to charge your 3G? I'm running into problems finding/building a backup that works with my 3G. Does your batteries fully recharge your 3G at least 1 cycle? Thanks!

[Sitnalta]

I have no idea, I don't own an iPhone. But I do own an iPod Touch 2G and it works fine with it. Basically, if an old ipod charger works, then this will work.

[Strad Master]

Is it possible to use a one 4 AA battery holder rather than 4 single ones?

[rupe33]

Out of curiousity - how much charge were you able to give an iPod? Would it be, say, a full charge from a dead battery - or somewhere in between? Am thinking about making one of these as a backup for the times I might not be near my car or wall chargers. Long travel times sometimes can drain that iPod completely!

[Sitnalta]

Well, it should supply at least 2 full charges. But I cannot verify that with my Generation 4 iPod.