Battery Location Mock Up. What do you think?

I am planning to run a dual battery setup. I want to keep the center of gravity as low as possible and connect as much weight as possible to the frame in order to keep it off the body. Here's what I'm thinking. Build a battery box to sit in the location batteries are mocked up in the picture. Run a skidplate from the transfer crossmember under the battery box and secure up to the crossmember above the back of the box.

Access to the batteries will be through a removable "door" in the battery box. I will remote locate a battery control station so there will only be a few wires going down to the actual batteries. Hopefully it will only be a pain once a year to get to them for servicing.

It will be forward enough to miss the rear end and use up open space. I hope the pics do a decent job of showing all the angles the way I see them.

Has anyone else done this? How did it come out? What am I not seeing here? Comments, questions and smart remarks are welcome. I am planning to run the exhaust down the passenger side and the muffler across the space between the two rear crossmembers and exit on the opposite side of the fuel fill. I'll try to throw in one pic with the fuel tank mocked up too.

Love the site and it has come in handy lots of times. I hope to start contributing more as I get deeper in this thing. I have all my pics posted in my photo album on this site and I think I made it so everyone can see them.

 

What are you looking to use the Jeep for-----I would be wary of any damage to the batteries if you plan on doing any heavy duty off roading/rock crawling. A damaged battery is a good source of ignition for a fire, and the location you have shown is not going to be easily accessible.......

What is the fuel tank from???

Stock Jeep tank, or other vehicle?

Do you know the gallon capacity?

 

Very interesting idea.

Just a couple of things to think about. Your drive shaft will be very close to your exhaust running it down the passenger side. I would also be worried about interferance between the axle and the muffler as well when you get into the harder stuff off-road.

I almost ripped the exhjaust off of my CJ when I took a *HARD* off-camber bump. The axle wrapped up and the u-joint caught the exhaust and tore it up pretty bad. I thought I had plenty of space between them. I obviously did not.

 

Both good comments guys... and things that I'm thinking about too.

Mike, The jeep will mainly be used for trails in the mountains and some playing in the sand dunes. I keep saying I'm "building it for baja, but using it in the backyard" so that may show my intent. I am planning a box that will not allow movement and securing it on shock absorbing pads. With the steel box and a skidplate, i'm not too worried about anything getting to it.

The tank is from a '82 DJ (mail jeep) and fits perfect between the narrow frame. I think it holds 12 gallons but not sure. I got it at J&W auto wrecking in Sacramento.

HH... The box will be 6 inches from the driveline so I'm hoping that will clear. I can move it a little further toward the framerail but probably not much. My thought is the rear end won't move that much laterally, not matter what i get it into.

Does anyone have any numbers on lateral movement. I would think my tires will stop it by hitting the body before it could move that far.

 

I am more concerned with the driveshaft hitting the exhaust not the battery box.

 

I guess i have battery box on the brain this morning. How much room did you have from the driveline to the exhaust while sitting still?? I went out and measured and it looks like if I tuck the exhaust as close as comfortable in the frame, I'll have about 6 inches where it passes the yoke on the output shaft. Then by staying in the frame till it gets to the back axle and turning into the cavity between the crossmembers, i should stay well away from the driveline.

How was yours routed?

 

On my 72 it was run down under the drivers side with the muffler sitting up clos to the body and frame in front of the wheel wells. The pinion had to have moved up at least 6 inches and over about 4 to contact the exchaust where I has it mounted. But appartently that was not sufficent with my soft springs.

 

I know you want to keep the CG as low as possible but, it looks like you have room to raise the batts up a bit. I think I would if I could and, you'd still be lowering the CG from the stock numbers as the batteries will be lower than the stock location. I would also be a little concerned about adding that weight to the driver's side. Me personally, I'm usually don't have a passenger so that would put the added weight of 2 batteries on my side and no counter weight on the pass side making me unbalanced. I guess they will be fully enclosed so there is no concern with grease flying off the u joints and splattering the batts all up. Other than that, I like the idea. Low CG is good.

 

So are your fuel lines gonna be by the batteries or exhaust?, either one doesn't mix well with fuel. Not trying to be overly critical, just trying to offer some additional input.

 

This is a concern of mine too. I told the wife she will have to gain a lot of weight to counter me and these batteries, but she's not willing for some reason.

I can raise them up another inch or two before I start getting into the bottom of the body. I figured out I can move them forward, if I stand them up but that will change the aproach of how I service them.

Plan B is to build a battery box behind the seats, across the front of the bed area and make it house the two batteries and the "battery control center". Then i could move the batts to her side or split them to keep "balance", since the box would be 3 feet wide and the batts are only 21 inches total. It would solve the access issue and still lower COG a little bit.

BTW, I'm using two of the red top Optimas for this part of the project so they are less likely to leak in a rollover etc.

Hawk... This would lead to me putting the exhaust in this area since i'm not filling it with battery box. I'll keep those clearances in mind that you had and maybe go with one of the smaller round exhausts as long as they'll keep enough of the noise down. Thanks for the heads up.

More to think about. Any other suggestions for battery location??? Like I said, I'm trying to keep from hanging too much weight on the body as well as lower the COG.

thanks guys

 

Thats what i love about this site. The more sets of eyes....or minds...looking at it will point out those little things that can become big things if not thought about in time.

Actually, I was thinking of running them on the batt side since it will be enclosed and Optima batts....but even that would put it runing past the exhaust for a bit.

I do have a skid plate for the fuel tank as well, but putting the exhaust where i am talking about may be an issue. Glad I'm still at the drawing board.

Plan B is looking better all the time.

thanks

 

Didn't know you could lay battery s on it side
like the concept I've been struggling on where to put a battery in my 3b
think I may look into running something similar behind rear axle away from the exhaust and fuel lines

 

I saw a pic of a JEEP where a guy used a tool box lid to gain access to his battery which he had mounted under the bed area of the JEEP. Ofcourse, your fuel tank is there. How about a similar approach but with the batteries mounted forward of the crossmember that goes under the bed area. Not sure of what clearance issues that may bring up. I had a box made for dual batteries mounted in the bed area which ran the entire length of the inner fender and was probably 1/3 the width of the bed. Also had a small tool box built into it and all lockable. Never got my second battery, used up a lot of valuable cargo space. Took it out and gave it to a buddy. Battery is back under the hood. I hope your plan works out better. I'm gonna want that second battery capability one day and haven't come up with an idea that satisfied me yet.

 

Cargo space is the main reason I'm trying to stay out of the bed area also. I kinda like the idea of at least partially "burying" the box in the bed area. I'll take some measurements tonight and see if that would work as far forward as possible. I've thought about moving the crossmember that is under there anyway and I can at least bury it as deep as the bottom of that crossmember.

Another thought crossed my mind after reading your post. I have only thought of locating the two batteries close to each other but maybe I need to think about it from the angle of anywhere they'll fit and serve the purpose.

Thanks for the input.

 

Can you bury a battery box under the passenger seat? This way it's a more even weight distributions, and maybe easier access.

 

Fording deep water or mudholes might be a real drag with those batteries mounted that low too. Unless you are going water tight, and I think that might be pretty tough to accomplish.

 

Do keep us posted on how you go about it and what you come up with. I sorta thought about under the driver's seat as opposed to under the pass seat, mainly because I like the underseat toolbox. But that put me right back at weight distribution issues again. Maybe they would fit under the pass seat like was said. Potential noxious fume issues in the passenger compartment would become non-issues with the sealed batteries I guess. Never thought of separating them.

 

Posi...after looking at your avatar, I can see why you bring up water tight. I gave that some thought and had planned to do all i could to avoid that being a problem. A totally water tight box would be difficult and a not quite totally water tight might let water in but not out. I would seal it as much as possible and cover the connections with RTV but that still may not do it.

Last night I found an old ammo can that is perfect for the behind the seat battery box if i go that way. It is 29Wx11Hx11deep and the Optimas fit in with just enough room for some shock absorbing matierial to surround them. I can wait to see how things weigh out balance wise and then secure them to whichever side is lighter when we get all geared up.

This puts them in the cab area but if I need to vent the box, I can vent it to underneath the bed. I'm not planning a backseat and have a camping box already that will still fit perfect in the back to hold other gear. The ammo can will have enough room to put some other goodies too. Heck, I may not even "bury" it, just mount it to the bed.

Doing this would allow me to run the exhaust down the passenger side and put the muffler in that space i was trying to put the batteries. I love dreaming up stuff and fabricating but sometimes my dreams turn to nightmares. Thanks for letting me bounce this off you guys.

I'll throw in a pic of the bed and I'm thinking of mounting that can pretty much right up behind the seats close to the bar of the cage that runs back there. This jeep came with a full cage so it has two bars running under the seats. The tool box is gone and now that I am putting the DJ tank between the frame rails in the back, the underseat tank is gone too. That allowed me to lower that part of the cage to get a little more headroom.

 

I only am using one battery but something similar to what you propose. Mine is behind the cross member but in front of the axle.

This shot is from 1975 or so and a lot has changed-but not the battery box as it has worked very well:

 

Duffer, I'll have to wait till I get home from work to see your pics. My work system doesn't let them through.

I was thinking about the balance issue that was brought up earlier and it has me wondering how much weight difference there really is. The fuel tank was there and full would have roughly weighed 80 pounds. The Optimas I have weigh 38 apiece, so as long as I don't make the box out of any plate heavier than necessary, I may not be adding that much more weight to that area. Hmmm.... more to think about.

I've been thinking about the waterproof issue also. I'll do everything I can to make the box waterproof and waterproof all the connections. I'm thinking the box will need to "breath" so I'll run a vent hose up into the frame somewhere with a breather type cap on it. Duffer, do you have any water issues?? I guess I could put a plug in the bottom too so after getting in water, I could pull the plug to see if anything comes out.

I've talked myself into and out of this a dozen times already. My work may block pictures but they can't block my daydreaming. Thanks for the input.