It was. I think it was disabled even though I didn't choose that option. Disabling essentially bricks the phone temporarily so that phone can't be detected/invaded via USB. I'm still not convinced that USB connection to battery is possible while disabled.
I believe the CPU of the phone controls charging. I read somewhere that one of the battery terminals provides battery temperature. If too hot the CPU disconnects the charger. No great leap to disconnect charger while disabled to make things more difficult for would-be snooper.
The battery is at half charge and losing 0.1v per week even though it has been put on charger overnight a few times. 5v appears near battery when charger is connected, but battery now reads 3.82v.