Ok, so let's start with the Batt connector. I'm assuming it's for the RTC, as such, is it 3V, 6V, etc? I have found a nice 3.7V LiPO battery with a JST connector already installed, so this seems like a nice fit if the 3.7V is ok. Also, is the Batt connector able to provide a charging current as well, or not? Now, the DC-IN. I'm assuming that's a battery connection for the board, so probably 12V? Also, is it capable of charging an attached battery?
the batt connection is only for adding a battery for the RTC it doesn't do any charging or anything, i think the intent here was a setup with a button battery or something but im sure a small lipo will work all the same the DC-IN is meant as a connection to power the board at the recommended 7-12v. This connection is best used when you are powering your board from a battery with a JST. There are many ways to do this if you want. A lot of RC car batteries will already have the right connector or you can add the JST connector yourself. There are a couple similar threads on this topic.
Wanted to make sure the EXT BATT connection did not have a charging circuit so adding a Lithium Ion 3V battery wouldn't cause an issue. As for the DC IN, still wondering if it had a charging circuit. It would be nice to act as an on-board UPS, so when the main's fail, the board can run on the battery until it hits a certian amount then power down nicely. When main's are restored, it can power back up and start charging the battery.
I dont believe it has charging circuit but you can have the dc-in to a battery and the barrel jack to the wall at the same time, you cant charge the battery with this setup
