Saturday, April 04, 2009

What Happens When You Short Out The Pack

Here is why I always wear gloves and eye protection!

Today, I was doing the spring battery maintenance, which consisted of topping off the water and tightening the battery terminal connections. For the tightning, I use a 1/2" box end wrench that is wrapped with electrical tape. The only exposed part is the box end.

Today, however, I needed an extra wrench and I just grabbed another, unwrapped wrench. Unfortunately, it slipped and shorted across the entire pack of batteries in the rear of the car. This was "only" eight of the sixteen in the car. When it crossed the terminals, it was like a Fourth of July display, with hot molten steel flying in all directions. I can't imagine what would happen if full pack had been shorted.

In the second picture, you can see chunks of molten steel and tracks across the battery tops where the hot metal rolled across.

Word to EV builders and owners: BE CAREFUL.