TrailManor Owner's Forum - View Single Post

06-21-2002, 06:23 PM

Wade,
I am not familiar with where the structural members (rectangular steel tubing) are located under the floor with respect to the battery box in your 2720SL. I assume that your battery sits in a tall plastic box - like mine did in our 3124SL. In our 3124SL the plastic box sat at the bottom of a cabinet. The upper aluminum sheet and foam were cut out in a crude rectangle, in which the box sat. My original battery was a "Marine-RV" battery that weighed about 40 pounds. When it died, I replaced it with an absorbed glass mat one (AGM) which weighs 65 pounds. Although there is a steel tube cross member about 1/8" under the bottom sheet in the area of the cut-out, I still did not feel comfortable with this heavy battery bouncing up and down on the lower aluminum sheet. Therefore I built a new battery box, made of stainless steel sheet. This new box was shallow (about 1-3/4" deep) and flanged at the top so that the flanges could rest on top of the floor. With this arrangement the total weight of box and battery are now carried by the entire thickness of the floor.

It may be wiser for you to do something similar to what I did rather than attempt to weld a steel brace under the cut-out area. Welding under the floor can be messy - your welding arc will be very close to the bottom aluminum sheet. If you don't melt the aluminum, at the very least you may melt the floor's foam core. If you can't make a steel box, you might consider making some bent bar supports for your battery box. These could be made out of 1/8" thick X 1" wide steel bar. Bend the bar into a flat dish shape (the inside should be wide enough for your battery box or battery) with a horizontal flange at each end. If the height of your dish shape is just less than 2" (thickness of floor), the bars will rest on top of the floor. Three of these bars might be ample support for a heavy battery. You could weld cross members to these three parallel bars and create a mesh-type of box. If you weld up a new battery box of mild steel, I suggest painting the inside of it with an epoxy paint to resist the corrosive effects of spilled battery acid.   :

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06-21-2002, 06:23 PM	#2
Larry_Loo Guest Posts: n/a	Re: Security of Floor Under Battery Box Wade, I am not familiar with where the structural members (rectangular steel tubing) are located under the floor with respect to the battery box in your 2720SL. I assume that your battery sits in a tall plastic box - like mine did in our 3124SL. In our 3124SL the plastic box sat at the bottom of a cabinet. The upper aluminum sheet and foam were cut out in a crude rectangle, in which the box sat. My original battery was a "Marine-RV" battery that weighed about 40 pounds. When it died, I replaced it with an absorbed glass mat one (AGM) which weighs 65 pounds. Although there is a steel tube cross member about 1/8" under the bottom sheet in the area of the cut-out, I still did not feel comfortable with this heavy battery bouncing up and down on the lower aluminum sheet. Therefore I built a new battery box, made of stainless steel sheet. This new box was shallow (about 1-3/4" deep) and flanged at the top so that the flanges could rest on top of the floor. With this arrangement the total weight of box and battery are now carried by the entire thickness of the floor. It may be wiser for you to do something similar to what I did rather than attempt to weld a steel brace under the cut-out area. Welding under the floor can be messy - your welding arc will be very close to the bottom aluminum sheet. If you don't melt the aluminum, at the very least you may melt the floor's foam core. If you can't make a steel box, you might consider making some bent bar supports for your battery box. These could be made out of 1/8" thick X 1" wide steel bar. Bend the bar into a flat dish shape (the inside should be wide enough for your battery box or battery) with a horizontal flange at each end. If the height of your dish shape is just less than 2" (thickness of floor), the bars will rest on top of the floor. Three of these bars might be ample support for a heavy battery. You could weld cross members to these three parallel bars and create a mesh-type of box. If you weld up a new battery box of mild steel, I suggest painting the inside of it with an epoxy paint to resist the corrosive effects of spilled battery acid.   :  :