Only if the battery had a problem to begin with would you mess it up trickle charging it for that long (i.e. dead cell, low water, leak, etc.) what happened was the battery actually charged over 15 volts if it was still connected to the vehicles electrical system it triggered a security code in the ecm. The computer is telling you it is seeing more than 15.2 volts in the battery and will not let the engine operate to save your altenator and various other electronic components which are rated at the ecm's max voltage setting. Hook a 12v light or motor to your battery and bring the voltage below 15v and you should be ok.

I assume the car would not start, that was the reason for charging the battery in the first place? Most modern battery chargers have a circuit that as the battery "fills up", drop the amperage to maintenance level or 2 amps. Pull the battery and have it checked. I would also have the alternator checked. It may not be working wright.