Quote:
Originally Posted by WIBadger
skylarkva @ post #14:
I realize you have already spent some money on the fabricated battery tray. However, I would have recommended that you NOT do that. As I understand from your write-up, the bumper is supporting the tray and batteries. If my understanding is correct, a couple of things to note. The bumper is the weak link in your setup.
|
This is a valid concern, but not that I did reinforce the bumper using the Mount-n-lock brackets. The welds are now reinforced by a steel bracket bolted to the frame.
But, the usual failure point on bumpers has more to do with torque applied to the bumper than lateral forces pressing down. Bike racks and storage trays hang out behind the bumper, so as you bounce down the road you are getting the weight of your cargo on the end of a lever trying to twist the center.
In this case the batteries have a 7 inch base, on a 4 inch surface. They are slightly offset to fit, so about an inch overhang on the camper side and 2 inches to the rear. Being strapped down tightly, they don't bounce the way a cantilevered load would, and they are applying force directly downwards, so it's a completely different set of forces at play. I've also positioned them at one side, over the frame attachment point.
Quote:
Originally Posted by WIBadger
skylarkva @ post #14:
Also, the batteries may have a shorter life span due to damage of the lead plates inside the batteries from the road shock/vibration.
|
Also something I thought through. As above, the batteries aren't bouncing in the same way that a cantilevered load would, being firmly attached to the bumper/frame. There would be a small difference in this case between vibration at the front and vibration at the rear. I decided that the added beefiness of the golf cart batteries I'm using over the standard marine hybrid battery is enough to offset that. Ask me in 5 or 6 years!
A couple pics-
Note the Mount-n-lock bracket around the bottom & back of the bumper.
You can just see the breaker for the positive side in there. Negative is attached to one of the bolts for the support bracket, behind the frame rail in this shot.