Sunday, March 31, 2013

Portable Power Supply

Hi ! First of all happy Easter to everyone. If you haven’t seen it yet, go watch my reel, I hope you’ll like it.

Currently I’m working on a project that uses Raspberry Pi, but it requires Pi to be portable. This raises a question of power supply. Of course, I could just use 4 AA batteries or something temporary, but idea of portable power supply has been in my mind for some time. Once again I decided to use Nokia LiPo batteries, since they are great, and I have a lot of them. I used 3 x 1500 mAh ones so it gives me about 4.5 Ah to work with, which is not bad at all. At ebay I found these 3.7V to 5V booster converters, they’re great so I’ve already bought two of them. There was some problem with grounding, because circuit wasn’t working after resetting, so I had to connect battery and output ground with schottky diode, which solved the problem. I decided to put it all in an altoids tin. I still have lot of them from the times when I was building portable circuits. I have to say this thing is a beast, it has no problems with powering things like Arduino, Raspberry Pi or even charging my phone. Only problem is that circuit doesn’t have control of how much is being drawn from batteries, so when I’m charging my phone, circuit is giving out something like 1 ampere, and it gets really hot immediately. But that doesn’t matter since I will only be using it on my bench. Having handy 5V supply available every time is great.


  1. How do you charge batteries? What about discharge protection?

    1. Well I am not using it currently, so I've added there only header connector and I charge it with custom usb cable. In terms of discharge protection, circuit has it built in.

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