Battery Charge doesn't work if starting when EN grounded

[Rftop]

What firmware version are you running?

This post by @avtolstoy might be a good starting point for you:

Boron Devices Stop Charging deviceOS@1.5.0

When looking into these types of issues, I suggest getting a dump of the actual PMIC state. Something along the lines of: void loop() { { PMIC power(true); Log.trace("Current PMIC settings:"); Log.trace("VIN Vmin: %u", power.getInputVoltageLimit()); Log.trace("VIN Imax: %u", power.getInputCurrentLimit()); Log.trace("Ichg: %u", power.getChargeCurrentValue()); Log.trace("Iterm: %u", power.getChargeVoltageValue()); int powerSource = Syst…

[Edit] - This may not help in your case, but for Solar Recharged Boron's I use the USB connector for the input source.
I get the same results as you when using Vin(Vusb) pin, but charging will resume during/after an EN Pin Shutdown when using the USB connector. I have no idea why