#bq25185

, which gives a nice clean 1A with a small bill of materials. Now you can use USB, DC, or solar to charge your favorite lipoly or liion chip and get 5V output. Maybe we'll make a version that can handle 3.6V LiFePO4 batteries, too? It's easy to set the bq to handle those by changing a single resistor.

We covered the BQ25185 (https://www.digikey.com/short/z1f5vhzv) on a recent Desk of Ladyada; it's a nice upgrade to the MCP73831 (https://www.digikey.com/short/vpvwfn05) or MCP73833 (https://www.digikey.com/short/32hzp4zp): it has high input voltage support, up to 18VDC, multi-chemistry charging such as for LiFePO4 not just Li-Poly/Li-Ion, power path for separated load supply with 4.5V regulated max out, two status pins, up to 1A output, and solar panel support by tracking the input voltage. It's not much more expensive and saves a lot of extra components. here's a breakout to let us start trying out this chip.

We had a previous version of this 3.3V buck output board with an MCP73831, but now we've replaced it with a BQ25185, which makes it a little more flexible: Vin can be up to 18V, and solar panels will work, too. There's also a power path and 4.5V regulated output. This charger chip can handle LiFePO4, but for that chip, we might swap the buck for a buck-boost or a boost / LDO to get the solid 3.3V output. Coming soon.