I am connecting my brand new mkr1310 with a liiom 1200mah battery 3.7v that has a built in BMS. Like the ones from ebay or china.
The batteries are working and charged. Mulimeter Shows 3.7v. So the battery is not empty or in any blocked mode.
When i connect the battery directly to VIN the MKR comes up.
If i power the MKR with USB it comes up.
But if i connect with JST nothing happens, no charging while with usb, no charging led, and if the battery is connected alone without parallel usb connection, nothing happens.
I cant measure any voltage on 5v or vvc or even on the JST pins or pads on the backside.
I am really confused what the problem could be here.
I tried different mkrs and different batteries.
I tried to connect the battery the other way round to see if there is a wrong pin setting for +- on the JST or the battery itself.
Nothing happens.
Generally not good idea.
Anyway, if you are able to connect it "the other way round" you don't have proper JST connector on your battery. Maybe this battery connector doesn't make contact with the MKR JST connector.
Yes, i made sure the battery has not a wrong pin assignment and the plus pole is the one close to the USB for the JST.
But the JST connector cannot be the problem itself. If i connect the batterie without JST female directly as a wire to the JST pads (backside unter the JST) i dont get power as well.
Even if i run (working) with VIN and GND, i cant measure anything at the JST or the JST pads (as a indicator for charging)
I tried 2 batteries and 2 brand new 1310 board. And i cutted the battery JST and put the cables directly to the PIN pads and as well to the JST pins on the board. Nothing.
There is a fuse F2 that you may have blown. If so J7 the battery connector is isolated. If you connected the battery backwards that would blow the fuse. I do not have this Arduino or any experience with it. I got this information from the schematic: https://docs.arduino.cc/resources/schematics/ABX00029-schematics.pdf
Great hint, you qre absolutly right.
But regarding the scheme as well, this would mean running the battery power not over the JST, instead connecting via the pin pads + -, it should bypass a burned fuse F2.
What do you think?
Or whats the schematics circle symbol?
