My battery is way up front under the fuel tank. However, there is a connector coming from the on/off switch which is accesible. Is this connector meant to charge the battery with?

If charging with that connector, does it matter what position the switch is in?

Also, I think we left the power switch on after my last flight yesterday, even though the radio was off, and this morning, nothing works. Will the battery discharge when the power switch is left on?