You can easily tell if it was a static discharge. The discharge is momentary and it is gone. A second touch to the same surface will show no further discharge. There are exceptions, but, not in this case. An actual shock is continuous, in addition, a repeat touch of the same surface will shock you again.
The garage should have all receptacles on GFCI circuits, therefore, the receptacle GFCI outlet or branch circuit, circuit breaker should have tripped. Let's play devils advocate, and assume it was not a static discharge there are then a couple of possibilities:
1. A large percentage of all GFCI receptacles manufactured prior to 2007 are faulty, the internal electronic sensing circuit fails. When they fail they will continue to supply the circuit. Since 2007 a change made by UL requires the GFCI receptacle to open the circuit when the electronics fails. If your GFCI was faulty and an older model (pre 2007) the receptacle would not have protected you and you would have been shocked. Conversely, theoretically you cannot receive multiple shocks if the GFCI is working.
2. The next question is, why would it happen, there are two possibilities, you have a tool or appliance with bad insulation. The most obvious is that the battery charger is faulty. To test it, set it up on the battery and plug it into a GFCI that is known to be operating correctly. The second problem could be that somewhere within the building a neutral and ground wire have been swapped. If you decide it is not a static discharge and the charger is not faulty, get yourself a receptacle polarity tester and go to it.
Hey today I was trying to take some exhaust off so I was laying under the rear of the car. my face touched the frame and I got a zap. Anyways, it became uncomfortable working on my car so i tried to figure out what was wrong. It ends up i took off the trickle charger and the zaps were gone. Is this normal when on a charger or do I have a short somewhere.
