Yay I’m done with another small kit. This one is a nice battery-powered USB charger. You can plug in anything that charges over USB like iPods, cameras, cell phones, etc. to get a lot more run-time. It runs off of 2 AA batteries, alkaline or rechargeables and has 2.5x more juice than a 9V-powered design.
iPod video (tested, using alkaline batteries): 3hrs more video (1 full recharge)
iPod shuffle (unverified): 60 hours more (5 full recharges)
iPod mini (unverified): 26 hours more (1.5 full recharges)
This project is suitable for beginners, some soldering tools are necessary but even if you’ve never soldered before it should be pretty easy. You can etch a circuitboard and/or breadboard this up, or simply buy a kit.
I also spent a bunch of time documenting the process by which kits are born, so that people can learn about how to design stuff like this.
Thanks to EYEBEAM Openlab for supporting this project as part of my fellowship!
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You know what would be even more insane? If you could charge LiON/NiMH batteries by plugging a wall wart into the MintyBoost.
Oh, even more insane than that would be to do a pass-through once the LiON/NiMH batteries were done charging so that you’d charge the target USB device once the MintyBoost was done charging.
I thought about it but, well, there isnt much space 🙂 I figured this would be simple and cheap enough…
I haven’t done anything like this in while, but it looks like fun. I’m just not ready to spend $100 on a soldering iron. Would this one work? It got pretty good reviews, but I’m not sure if it can handle the delicate electronics in this project. Actually, I have no idea what I’m talking about, so any advice would be appreciated.
sure, that iron is great, its not very delicate work.. im just very finicky about my tools 🙂
One more quick question – can I use any rechargable AAs with this kit?
Nice circuit you have. I had a similar concept using LM2623. The outcome is similar to your design. But the problem is I hurt my eyes and it just takes so much time soldering an SMD. So I turned to MAX757 and I was surprised that you too have a design based on the 756.
I was happy with the MAX757 with my iPod 30G Video. Now that I tried it with the other devices, I was challenged to think why it wouldn’t work so I searched the Net. Good thing is that I found your site. There is more to the USB stuff than I thought.
Thank you for the added pull up/down resistors.. I never thought of this. You are right, I should have bought a commercial charger and dismantle it to see how they are dong things.
I also would like to thank MAX tech guys.. they have been helpful too in the circuit design.