Do I Need A Grounded Outlet And Grounding Cable To Plug In A Car Battery Charger
Posted in Car Batteries | Asked on Apr 13, 2010
I recently bought a 10-amp charger to charge my lightweight AGM car battery, however there are two problems.
1. It says in bold to only use a 3-prong grounded outlet to plug in the charger. I live in an old apartment building with only 2-prong outlets. Is it still relatively safe to use a 2 prong outlet with an adapter?
2. It also says that when charging the battery out of the car (which i am planning on doing, since the car is not near any outlets) to connect the negative post of the battery to a 24″ or longer 6-awg insulated grounding strap, and then connect that grounding strap to the charger’s negative alligator clamp. It says never to connect both alligator clamps to the positive and negative posts on the battery directly. If this was actually required, shouldn’t it have came with a grounding cable? It didn’t… can i try connecting both clamps directly to the posts, or will it blow up or something bad?
There are 2 Answers for "Do I Need A Grounded Outlet And Grounding Cable To Plug In A Car Battery Charger"
Connecting both to the terminals is dangerous. It can create sparks igniting the battery gasses, or could damage your battery.
As for the third prong ground, it may very well work without a ground, but it would be dangerous as any electrical issues would not be grounded to the ground, but grounded to you when you go to touch something.
The purpose of connecting the battery a safe distance from the negative post is to prevent any inevitable sparks from igniting the hydrogen sulfide that may be present around the battery – and this can cause an explosion. It’s an unlikely event if the charger is in the off position when connected and disconnected – but why take the chance at all – use an extension wire as suggested.
The need for a ground plug is to prevent an electrical shock – if the polarity in the two prong outlet is reversed (not uncommon, especially if Harry Homeowner did the wiring) the charger’s housing could become 120 volts live to ground – and, needless to say, that’s a real shock hazard, or worse. Use an adaptor if you must, but never cut the ground prong off the plug (also, a common occurrence).