Normal battery on a start/stop vehicle?

[Ubique]

It won't have anything to do with the injector voltage - this is controlled by a DC-DC converter in the engine control module, the input range is quite wide whereas the output voltage is tightly regulated. Most likely a 'soft reset' caused by the battery disconnect/reconnect, it's a well-known diagnostic 'first step' if there's nothing relevant in the DTC's ;-)