Supporting the battery(s) in SL models

**Bill** · 11-10-2010, 02:37 PM

In the 2720SL, the battery is mounted at the left rear corner of the compartment (as you peer in through the door). I imagine that this is to put the battery close to the wall, where there is added strength to support its weight. I often wondered, though, if it might not make sense to move the battery to the right, maybe all the way into the right corner. A length of 1x6 on the floor ought to spread the weight and provide enough strength to support it - and it sure would be easier to get out.

If I am not mistaken, Mike Laupp did a major rework of the battery location several years ago. I think the thread is here

http://www.trailmanorowners.com/foru...ead.php?t=1696

Mike, I sure would like to hear from you about long-term success here.

Bill

**ShrimpBurrito** · 11-10-2010, 02:46 PM

Actually, on my 2720SL, the battery was factory-installed to the right, as you peer in through the door. I followed Mike Laupp's rework that Bill referred to, and it works great. The thread he described his work in is here:

http://trailmanorowners.com/forum/showthread.php?t=1696

Dave

**mjlaupp** · 11-10-2010, 04:50 PM

Bill,

I put those batteries and a battery box into 2 2720SL's. I have also replaced them once when the 6300 converter boiled them dry and ruined them. My current 3326 has the batteries in 2 conventional battery boxes, 1 on the left and 1 on the right forward wall of the compartment, installed by the dealer or previous owner. I have not moved the 3326 batteries.

On the 2720SL's, I installed the batteries into the box after it was in place using a battery strap designed for the T105's. the steps are: 1) Set the battery on the back bumper. (If you have an aluminum bumper cover, be sure to protect it from contact with the batteries. There may be some battery acid residue on the bottom of the batteries.) 2) Place one foot on the bumper and place your elbow(s) on that knee. 3) Use a forearm curl to lift the battery over the door sill. No pressure on the back. 4) Repeat the forearm curl to place the battery in the box, this time with your head and shoulders inside the compartment. I'm big and don't bend very easy and I was able to complete this with minimal stress to my back.

Wavery · 11-10-2010, 06:04 PM

Quote:

Originally Posted by ShrimpBurrito

Actually, on my 2720SL, the battery was factory-installed to the right, as you peer in through the door. I followed Mike Laupp's rework that Bill referred to, and it works great. The thread he described his work in is here:

http://trailmanorowners.com/forum/showthread.php?t=1696

Dave

Good thread......but I have a comment...............

I wonder why he didn't recess the batteries to the sub-floor. That gives 3" more clearance and there is plenty of support. It also eliminates the need for the tie downs. The factory battery in my trailer didn't have a tie-down. Those batteries sure aren't going to jump out of that hole.

I really like the idea of mounting the batteries more to the center line of the trailer. I wish that I would have thought of that

. The original battery weighs ~35#....this pair of Trojans weighs about 100# more. That's a substantial amount of shock loading on that side of the axle, that far back.......

Back to the drawing board

.

**ShrimpBurrito** · 11-10-2010, 06:20 PM

Quote:

Originally Posted by harveyrv

I wonder why he didn't recess the batteries to the sub-floor. That gives 3" more clearance and there is plenty of support. It also eliminates the need for the tie downs.

Plenty of support? Not on mine. IIRC, the layers going from the top was something like: thin aluminum sheet, 1/8" plywood, 3" foam, thin aluminum sheet. Thus, the "sub floor" is simply a sheet of aluminum. The factory was able to recess the battery to the aluminum sheet because they installed it in a case that had a flange that extended outwards about 1-2" all the way around, several inches from the bottom. It is not like any battery box I have ever seen. (There is actually a picture of it in post #3 of Mike's thread: the box on the far left in the picture.) The box sat inside a wood frame to raise the case about 2", and thus, the entire weight of the battery and case was still supported by the top floor (including the plywood and foam) through that flange and frame.

If you cut out all the foam down to the aluminum skin on your TM and rely on it to support the batteries, I seriously doubt you would even make it out of the driveway with them inside the TM. Or at least that's what would happen on my TM

Dave

Wavery · 11-10-2010, 07:34 PM

Quote:

Originally Posted by ShrimpBurrito

Actually, on my 2720SL, the battery was factory-installed to the right, as you peer in through the door. I followed Mike Laupp's rework that Bill referred to, and it works great. The thread he described his work in is here:

http://trailmanorowners.com/forum/showthread.php?t=1696

Dave

Good thread......but I have a comment...............

I wonder why he didn't recess the batteries to the sub-floor. That gives 3" more clearance and there is plenty of support. It also eliminates the need for the tie downs.

I really like the idea of mounting the batteries more to the center line of the trailer but the right side of my outside cabinet ends right at the edge of the door (allowing more space for the inside cabinet). I would have to mount the batteries in the inside cabinet to get them close to the center-line. I wish that I would have thought of that

. The original battery weighs ~35#....this pair of Trojans weighs about 100# more. That's a substantial amount of shock loading on that side of the axle, that far back.......

Back to the drawing board

.................My wife's not going to like the solution to this problem.

Wavery · 11-14-2010, 04:47 PM

Well.......I went ahead and placed the batteries in the far left side (where the factory battery was). It doesn't seem to make any difference in the way that the trailer tows or anything. I was a bit concerned because between the solar panels and batteries, I have added nearly 150# on the far rear of the trailer.

I will weigh the tongue on Tuesday (Monday is jury duty). The trailer towed very well and there was no hint of swaying (which was my main concern).

Here's a pic of the final install on the solar panels.

Wavery · 12-21-2010, 01:47 PM

Quote:

Originally Posted by ShrimpBurrito

Plenty of support? Not on mine. IIRC, the layers going from the top was something like: thin aluminum sheet, 1/8" plywood, 3" foam, thin aluminum sheet. Thus, the "sub floor" is simply a sheet of aluminum. The factory was able to recess the battery to the aluminum sheet because they installed it in a case that had a flange that extended outwards about 1-2" all the way around, several inches from the bottom. It is not like any battery box I have ever seen. (There is actually a picture of it in post #3 of Mike's thread: the box on the far left in the picture.) The box sat inside a wood frame to raise the case about 2", and thus, the entire weight of the battery and case was still supported by the top floor (including the plywood and foam) through that flange and frame.

If you cut out all the foam down to the aluminum skin on your TM and rely on it to support the batteries, I seriously doubt you would even make it out of the driveway with them inside the TM. Or at least that's what would happen on my TM

Dave

Somehow, I missed his post........

On my '04, there is a sheet-metal panel that runs the width of the trailer (see attached pic), right under the battery. Plenty of support IMO but I will keep an eye on that panel for signs of stress. If it gets stressed, it should show up as a bend in the panel. If that happens, I can always reinforce. So far, so good.........~ 300 miles on it... Maybe they made that change with the new style bumper.........You're right though, if it wasn't for that panel, I would not have recessed the battery box.

scrubjaysnest · 12-21-2010, 04:31 PM

On the '11 2720SL it isn't sheet metal but the aluminum skin. The battery box sits on it with no other support. The lip of the battery box is about an inch above the floor. Didn't see any problems with a group 24 back there over 1100 miles. Time will tell.

Wavery · 12-21-2010, 04:54 PM

Quote:

Originally Posted by scrubjaysnest

On the '11 2720SL it isn't sheet metal but the aluminum skin. The battery box sits on it with no other support. The lip of the battery box is about an inch above the floor. Didn't see any problems with a group 24 back there over 1100 miles. Time will tell.

I think that if you look under your trailer, you will find that the bumper storage compartment extends back under the floor about 1 foot and is made of ~16G galvanized sheet-metal (at least that's what mine is). It forms a box about 6" high and 12" deep. The outer edge of the box is right under my battery box. It is fastened to the underside of the aluminum floor about every 6" along the length of the box (width of the trailer). The box construction should support several hundred pounds IMO, the way that it is fastened.