Hi, my MintyBoost works great, but now I'm trying to make a minimalist phone charger. I'm trying to use 3V button cells in series so I don't need the step up voltage regulator. Right now I just have power and ground to the respective USB terminals, with a 100uF cap in parallel. My device says it's charging, but the power % is decreasing! Any ideas? Please help, I'm a bit of a newb and trying to learn as I go.
Thank you,
Alex
Even smaller!
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- adafruit_support_bill
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Re: Even smaller!
You are not going to get the kind of current you need to charge a phone from button cells. Most phones need at least 500mA and those cells are designed for discharge rates in the micro-amp range. They have a pretty high internal resistance, so if you try to discharge them at more than a few milliamps, you get a large voltage drop and a decrease in effective capacity.
Please be positive and constructive with your questions and comments.