I tested them all and they worked pretty good. Board Input was 6.0 volts. The 18650 batteries (LIPO 3000 Ah and Lipo 1600 Ah) charged to exactly 4.275 volts and then the MOSFets (N-Channel -- U2) switched off the input volts.
With 2 car bulbs 21 W in parallel ==> 2.02 amps, I discharged the 18650 batteries and the bulbs switched off at 2.800 volts. That's exactly what the specs of the TI-IC bq29700 say.
To turn the battery the other way (P-Channel -- Q1) around into the position plus pol to minus and minus pol to + ==> I did not testet yet. I will do it as soon as possible, too.
The protection guard is a very good product. I bougth the last 5 boards and i am really happy
Item is good, but it took me a whole day to finally get it to work, because it needed two modifications, that are simple, but not obvious to figure out that they are needed, especially since you expect the board to just work out of the box.
1. CE must be tied to ground to enable the chip. Recommendation to seller: add a note to the documentation; and include a 2pin 0.1'' jumper so that CE can be easily shorted to ground in the header.
2. SCL and SDA *must* be pulled up to a positive voltage through resistors (I used 4.7k to Vbat); otherwise, the charger will work but will not respect Ilim setting: it will limit input current to 0.5A and as a result charging current will be around 0.6A (for Vin=5V) regardless of the actual setting via Iset R. Recommendation to seller: include pull up resistors on the next revision of the board add a Vbat header pin next to the Vio pin and include a 2pin 0.1'' jumper, so that it is easy to make the connection. I see that you already have the pull-ups. And, of course, add this to the documentation!
Adding these two modifications will make the board work in standalone mode out-of-the-box (solder header and add two jumpers). I would bet most users really care about standalone mode and are not going to connect to MCU, in which case stuff doesn't work out of the box the way things are now.
Additional note: I replaced R7 with 140ohm to get 1.8A charging current, and it works well.
Response from ambergarage | Jan. 24, 2018
BQ24250 doesn't need any modifications but is obvious that you need to adapt it to your application that should be a standalone mode or not. You can prefer standalone mode but other people can need more features.
About the points that you talked about: 1) CE pin must be tied to GND to enable the chip, this is explained in my website articles that I linked in the description and for example, only one cable is needed to do it. 2) SCL and SDA are already pulled up inside the breakout board!! You simply must choose the VIO voltage suitable to your application to use the I2C, also here only one connection is needed and also this is explained in my website articles that I linked in the description
I don't provide a documentation file into the tindie page if you search something like this... but if you read the entire description you can find links to my website of what exactly you are looking for.
At the end: Thanks to support my store!