Notecarrier not fully charging Lipo battery

Hardware Notecarrier AL
1

Hi there!

I’m currently trying to build an IoT device using the Notecarrier AL. Today, I have been looking into ensuring that the Lipo battery I am using is charging up properly. I am using a 3.7V 1800mAh battery with a max charge voltage of 4.2V. I have been monitoring the battery voltage from the VBAT pin on the Notecarrier as it is being charged on solar. Both my solar panel and battery are plugged into the JST connectors. However, the battery voltage appears to plateau around 4.00V to 4.05V. I even tried hooking up a 240V-5V recom unit (mains power to 5V DC) to V+, but this also produced the same result.

I do need to be able to fully charge my battery for my application. Has anyone come across this issue before? What do I need to do to fully charge my battery?

Additional info:
The battery I am using is a ZN-103450

2

I have found what went wrong and thought I’d share incase anyone else comes across the same problem. I had been powering the Notecarrier via mains through the V+ pin. While this does successfully power the notecard, when I had a look at the schematic for the Notecarrier, I found that the V+ pin is not connected to the battery charging circuit.

However, VUSB is connected. When I connected mains to the VUSB pin instead of V+, the battery started charging properly. I would only recommend doing this if you are never going to connect the Notecarrier to anything using the actual micro-USB port.