Monday, November 3, 2008

A wee bit of a problem here....

So what happens when you are coasting backwards a little too fast and hit the brakes, just as you go over a steep bank? This:


With the AMPhibian on top of me I began to question the benefit of adding 240lbs of batteries to a 500lb vehicle. Luckily since most of the weight was in the back I was able to lift the vehicle enough to crawl out from under it and walk back up to the house. After washing the blood off my face I remembered that the contactor switch was still on and the controller was still powered up. Walked back down and turned it off, made a weak attempt to push the vehicle back over, gave up, and walked back to the house and called for a ride to the emergency room. 9 stitches later I'm bruised but not beaten, and the AMPhibian is remarkably unscathed, I guess I cushioned the impact. With help from my father I used a come a long to winch it part way up, took out the batteries, flipped it back over, put them back in, and it seems to be working fine. I will be adding a rollcage, and better hold downs for the batteries since they did end up moving around quite a bit. Very glad I went with Odyssey sealed lead acid as opposed to flooded, and very glad this was an EV and not an ICE, since the gas tank would have been right over my head probably leaking all over me.

6 comments:

Anonymous said...

Now, in hindsight, why the hell there was no rollcage??

I'm glad to see you are OK!

-- Warped

John said...

It was on the "to do" list, just hadn't gotten around to it. Frankly, up until this point, it felt very stable. I have an old Blazer roll bar I think I can modify.

Ben N. said...

I was taking a look at at some technical specifications on a Prius a while back. I found out that they have a "rollover switch" in them.

Should the vehicle flip over, the battery pack is automatically disconnected.

On my EV conversion, it would be a pretty simple matter to connect a mercury switch to the main contactor to do the same thing. I didn't think such a thing was needed on my car, but maybe it's not such a bad idea on an off-road vehicle like the Amp-phibian.

PS: Very cool EV!

John said...

The problem with a mercury switch in the AMPhibian or any off road vehicle is even if I'm not upside down there is often a lot of bouncing around and severe driving angles. It would have to be some sort of switch that only triggered at greater than 90 degrees, forwards and backwards and side to side. There are inertia switches that will break contact after an impact but might not trigger on a rollover, I'll have to see how much force they take. It might have worked in this instance since it was more of a flip with a hard landing than a roll over.

Dave Keenan said...

You earlier wrote, "I'll try them all in the back at first. Hopefully it won't be too much weight back there." I'm glad those didn't turn out to be famous last words, but it seems that even after 9 stitches you're not getting it. By all means add a rollbar, but you really need to distribute the weight more evenly, while keeping it as low as possible and as close to the center as possible.

JP said...

Unfortunately the only way to put some of the batteries up front would be up under the nose, which would be the high point on the vehicle. Plus there is no structure there so it would take a lot of fabrication work. I'm just more cautious on hills now, and I expect eventually I'll just upgrade to lithium when these wear out.