We have a 2013 Fiesta - low mileage.
Recently we have started experiencing 2 issues, probably related.

1. The car will not start if you press the accelerator when starting the car. This seems bizarre, but the engine turns over and does not catch if you have a foot on the gas. No big deal - just don't put foot on accelerator.

2. More recently - and intermittently - total loss of all power when trying to start the car. Put key in and the dash lights come on as normal. Turn key and total shut down, no lights, no click from ignition, no radio, nothing. As if the car does not have a battery attached.
Get out of the car, try to lock/unlock with remote fob - nothing. Leave it a minute or two, and it seems to reset. Get back in, turn the key and everything is fine!!
Not sure if it is the key fob (I've changed the battery), the immobiliser (but why would the whole power cease) or the battery (seems to be connected fine)??
After the total power loss, when the car does eventually start, the date/time etc is reset as if the battery had been removed.

New battery needed?? Or maybe some sort of short in the ignition??

Help please??