Homemade Battery Box?

[jjonesnc]

Has anyone ever made their own battery box? if so how?
thanks friends!
-Jason

[Tarheel]

Plastic boxes are readily available and cheap. Go to any marine store such as West Marine and you will have a mess of them from which to choose. If you for whatever reason still want to build one then I would suggest that get some 3/8" plywood, a pint of west system epoxy with hardner, fiberglass tape and some micro wood filler.
make a template of your battery
transfer the template to the plywood
cut out the wood
mix the epoxy and coat both sides of the plywood using a foam roller. 3 coats light sanding between coats.
using brads tack the box together
mix epoxy and wood filler to a consistency of peanut butter
make a fillet on all of the inside corners including the bottom using a tool similar to a tongue depressor
after making the fillet remove excess epoxy
when the epoxy has set but before it has hardened cover the outside edges with glass tape and wet it with epoxy using a squeege and getting all air bubbles out
when the outside tape has set cover all inside joints in a similar fashion.
when the epoxy has cured coat the box inside and out with two or three additional coats of epoxy using a foam roller.
If the box will be exposed to sunlight then it should be painted or coated with a uv protector.
presto you have a battery box
or drill some holes in the bottom and you have a live well for your boat.

Not real certain that after you read this you will still call me friend LOL
But I have used this process to make a darkroom sink and drain board. It works well if you have a special application and there just doesn't seem to be a ready made product that will do the job.

[j54mark]

Do you need a custom one, or a replacement for the factory box? A replacement can be had at a RV salvage. Or you can buy battery boxes at boating suppliers.

Mark

[jjonesnc]

Thanks for the replies
Yeah what I really need is a replacement one but I thought I should learn to make one also. I had a loooong list of RV salvage yards all over the USA but it was lost in a reformat I did, forgot to save it. Cant remember where i got it, is there a list available somewhere?


Tarheel, I was in Moyock once as a kid, cool place. I might take you up on the Courtesy Parking one day!

Thanks Friends,
-Jason

[Tarheel]

Jason I would love to have you stop by. Maybe you could help me build a battery box for my 8N Ford tractor (1948).
Just curious did you come here to the boy scout camp?

[jjonesnc]

Tarheel, No I went with my father and a friend of his to visit some other friends of thiers. They were haveing a big party with a oyster feast and the works. it was around 1979 or so, was a great time!
-Jason

[Tarheel]

If you remember a name you will have to let me know. It was a small community then. Now all the Tidewater Virginians including me have invaded the town.

[GM Airstream]

Yes I built my own replacement battery box that goes between the A frame. Looked all over for a factory one and when we found one they wanted WAY too much money...

So we got on the cad computer and did the layout for on... bought the 12ga (0.105") sheet metal from the local metal supply and with the aid of a tig welder bent and welded up a factory replacement that actually was 2 inches higher so it could take the GC bats without having to have the extension put on it.

The final dimension we came up with is 12 inches deep by 15 inches wide and 13-3/4 deep going forward. to the top... we Added 2 - 1x1 x 14 bent out angle pieces to the sides... and 1 - 1x1 bent in at the back and 1-1.25x1 at the front(bolted in)

We bent a bottom pan and then added the sides and top angle pieces to it... with 1 inch angle tabs at the corner sections...to both seal it up and add strength to the corners.

Added the bent angle pieces to the top section... but left the forward 12x15 with a removable top angle brace with the door hinge bolted instead of welded in to accept the type 27/65 bats.

the reason for the bolted forward section being bolted is due to using the type 27/65 group bats ... if you ever wanted to go to those over the GC bats... you can get them in.

We placed it on the center line of the A frame from the exterior wall of the trailer... set the box in the frame with top cross members welded to the A frame section... leaving 3 inches below the frame and 2 inches above...

Cost came in for the metal was $120 but by making it 12 in tall took care of the extension that others have to add to theirs to get the GC bats in...

Yes it could be made from Alu... or SS but that would also drive up the cost's.



As to the existing battery boxes accessed from outside under the front couch...

I did look at cutting the existing battery boxes tops off and putting the GC's in from under the couch... but servicing and venting becomes a issue... as well as limited height under the couch.

although the sealed AGM's are use-able they are about twice the cost of the trojan 105s...

Can it be done.. yes... but one would have to be a fiberglass specialist.. and come up with a new box with a seal-a-ble top...

I am working with a friend of mine who is going this route... because he doesn't want to change the battery location or weight on the ball... so its another project to design and engineer... too bad airstream didn't make the org battery box from under the couch to accomidate the larger.. (higher) bats... again... great AS design engineering.

[Hittenstiehl]

We had ours made at our local air conditioning sheet metal business. I had never been inside a business like this and was totally enamored with all of their various vending devices.

And in awe of the little boxes that sat at the end of each table where all the little punch outs and scrap aluminum fell into.

[GM Airstream]

Had a nice talk with the engineers today at AS.... One thing that bothered me was that Andy (long time expert on AS) said in one of his emails that putting the bats inside the A frame... was not a good idea... and refer'd to some vibratory problems.

So we called and ask the manufacture... and strange he did say something about the
same referance... i.e changing the battery location to inside the A frame...frame problems.

Seems that the bats under the front couch may actually be vibration dampners for the A frame as a mass balance on the center of the beam engineering figures.

Their were several issues he brought up... in reguards to the bats going into the center of the A frame... behind the propane tanks...

one being the weight transfer from one location to the other..resulting in higher ball hitch weight..

second issue was the fact that the bats may not perform as good due to exposure...

third is the issue of road dirt etc contaminating the battery case top...

forth was of course.. theft...

The engineer I talked to has been their through 3 manufacture ownership... and was the senior structural.... saddly he is about to retire next month...

but he went on to say that the new trailers with the bats inside the A frame have a re-enforced frame to help keep the flexing down...

by placing the bats within the A frame will stiffen the frame in that area... things have to flex.. and now if placed their... will cause flex greater at a further location back within the front section of the trailer...
i.e it has to flex... and if you make one part of the beam (frame) more stiff... then the rest of the beam has more flexure...

I thought it interesting that by placing a weight in the center of the beam... dampens the vibration/flexing for the trailer frame on the forward section.

He laughed when he said.... we didn't put the bats under the couch just because it was a convient place... they actually serve two fold mechanical purpose .

The rest of the issues are common ... dirt on the top of the battery will cause faster self discarging... so also will cold weather effect the performance of them... (one can look at the manufactures TC chart to bear this out)

Theft is also a issue that can be addressed by postive locking.

The other issue that needs to be addressed is the total hitch weight... seems that the A frame is rated for about 1800 lbs bending moment.. thus they like for you to stay under the 10% trailer weight on the hitch... (the 15% value is the max.. safe no safety allowance)

So here is what we discussed... changing the weight forward .. adds about 140 lbs to the ball... flat dead weight... where as if you load the trailer its a percentage of the total load weight of the trailer... on the ball

Thus, by adding dead weight to the hitch... you can't load the trailer with as much .. where as if the bats weight is located further back it becomes a percentage of the bat weight that is added to the total load on the ball...

So if you take the 140 lbs of bats... you add it to the existing hitch weight... (650 + 140=790)
closer to the max weight of the hitch load... and you haven't even put anything in the trailer yet...

where as if you have the bat weight further back... (650 + (10% of 140)= 650+14=664... as the weight is now spread back to the trailer wheels instead of all of it being on the ball of the TV. (these are thumb figures... yours may vary)

No his suggestion was to retro fit the existing battery box under the couch... they recommend that you open up (cut) the top.. and use the AGM no maintenance GC bats which will fit into the box.. (has almost the same footprint as the type 24's.. just taller in dimension...)

thus you can installing them is under the couch... at the manufacture design point... and you will need to seal up the hull doors...to keep outside air from entering under the couch through the battery compartment.

as the issue here is the venting of the bats... AGM are sealed and so no hydrogen gas to deal with... ONLY PROBLEM IS THAT THEY ARE 2 TO 3 TIMES MORE EXPENSIVE THAN THE FLOODED GC BATS...

He gave me the recomended battery part no... and also the latest converter (4 Stage) and inverter all in one.

... and of course they don't support any modifications to the trailer as built...

So he strongly recommended that you keep the bats in the manufactured location instead of placing them within the A frame.

to which we are looking at the way to modify the current location to accept the flooded GC batteries... as they are the way to go... over the so called deep cycle automotive bats...

Will write more about the design and modification of the bat compartment...so others can see how one can install and service them.

let the critics begin... grin

[GM Airstream]

we have come up with a idea... for our friends '73

so as to place the flooded torjan t-105 GC bats back where the orginal group 24 deep cycle light weight bats org'ly went under the couch...and have them vent like factory...

We first considered modifying the orgin'al batt box.. but due to the type of material used.. gave up on that. It would become to labor intensive...

... changing to AGM bats of the same cap... is 3 times more expensive.. and the battery would be hanging out the top of the existing box with the top removed... tacky...

and... what about servicing the flooded batts... going under the couch is a idea.. but one would rather be able to service them from the outside.. to keep the spillage (acid damages) from being inside the trailer...

So with these guidelines we came up with ..
*the bats have to be acce'ble from the outside...
*we want to use the existing compartments...
*and we want the trojan 105 GC bats

I can't understand why this wheel' has not been invented yet... sure others have checked out the same before... wonder why someone hasn't... and why isn't AS putting out a modification kit too... seems simple... to accomadate the taller GC bats as they almost have the same footprint on the floor... just taller for these trailers

So the current thinking is ....

Not to modify the existing boxes... instead its less labor intensive to just build new ones out of fiberglass or other material...

... will require is that you remove the existing battery boxes on either side of the trailer... and possibly

*remove the existing door/lock etc... cut the lower section with the hinge and then moving the bracket up .

it is interesting that the door might be big enough to take the 11.3 inch height of the GC bats... but getting by the latch clip...presents a problem... the box area for the battery placement compartment behind...the door... is not high enough where the new bat will set...
(measures 10 inches high x 7.5 inches wide and 13 inches deep...on ours... )

although AS did put a header on the existing box... going through the forward trailer wall... which which measures 12-5/8 x 10... and may be high enough... to modify with the new bat box height...by going directly back for the 12 inches as new GC bats require... if this is so.. then the door and hinge may not need to be changed... but, we measured the one we are working on.. and it is a tight fit with the new GC trojans ...the word is others may vary... so that has to be taken into account.

Thus it will require one to make new battery boxes... and heighting the door if required... making a new door out of 6061 3/16 plate... and get rid of the casting.

We are checking to see if a local fiberglass shop can fabracate a larger interior battery box for us... as we finished the cad cam design today... and sent the plans over to them... the major interior dimensions for the battery compartment went from 10 inches to 12 high and the width from 7.5 inches to 7.75 so the cables will fit the battery position with the entry points the same fittings... We spec'ed out a 10 layer G20 type fabric with epoxy res'n. It should be strong enough and also impervious to the acid if any.

If all works out.. then the new GC bats will fit under the couch in the same place that the factory Group 24s did... and it would be a less expensive mod to place the GC bats into the trailer which will supplement the factory position... keeping them cleaner, warmer and less exposure behind a locked door as factory designed.

Once the bats are in place .. then its a simple matter to rewire under the couch for the new T-105s that should last longer and provide more power... cheaper too...

I may go back and modify my '85 if all this works.. and take the bats out of the A frame box... and use it for storage instead... love the idea of having the bats more out of the way and back where the factory placed them...

[GM Airstream]

UPDATE:
After looking, measur'n and building a lot of little cardboard boxes to simulate the different batteries... the conclusion came...

Airstream does sell the battery box that goes in the A frame... its a new design so as to handle the deeper trojan battery (GC2) which are the perfered ones... it cost $123.46 from the factory... (p/n 916044 tool box) lid not included... that cost another 112.62 if you want that too.. but the existing lid should still work... just drill the rivets and remove.. replace on the new box...
The new box can handle just bout any GC2, 24,27,65 series batteries... your choice... however you will need to remove the front lip and replace with a piece of angle drilled and bolted for the 27/65 group bats...
And if your rich... you can go with the new trojan 12 volt bats...but, they are short amperage compaired to the GC-2's

As to going out and having a AirCond or sheet metal shop build you one... the cost estimating of that exceeds what you can get a replacement box from A/S for... so best to just buy it directly through the dealer from airstream as the most econ method of getting one... Of course you are going to have to take it down to a welder to have it installed... so the price doesn't include that...

Those of you who thing that a air cond shop would be better.. please stay away from the galv metal that they use for ducting. It is most difficult to get welded and of course the paint has a hard time through the years to stay on it too... and it actually does little to keep the acid spillage from eating the metal.

(I would post the engineering drawings for the new one here but, due to the blog memory space... can't)

The outside dim is 15.15 x 15.15 x 12.07 deep... so they did modify their existing 'tool box' to handle the GC2 bats...

It was interesting that they are welded boxes... which airstream doesn't make...instead buys from the frame manufacture. (oh you didn't know that AS doesn't make the frame for your trailer.. hmmm)

The new box extends down below the frame rails... instead of the 2 inches up above it as well...
AS now places almost all the RV bats in the A frame area.. according to the engineering group... and they seem not to have any problems...

Indeed you can retro fit AS back to the '70's with the new battery box... by fitting and welding it into the A frame... Some of the 80's had smaller boxes already their but were refered to as 'tool storage boxes'

A/s did not answer the question as to how much weight the new battery box can handle... we noted on the engineering drawings that they have gone to 14 ga sheet metal instead of the older 12ga. For the battery I don't thin the extra thickness or weight carry ability is much of a gain for going with the 12 ga.. like I did when I built mine.

... and what to do with the old battery compartment that goes under the front couch... well two options here...
One is to disable the battery cables... and use them for storage... I am sure you can come up with all kinds of things to put into them from hitch grease and setup tools to wheel chocks and Misc other things that can live outside in the elements.. as the boxes are vented to the outside...
One word of caution.. they bottoms and sides are plastic.. and if you crack/break it you now have a air leak from outside to the under side of the interior of the trailer.. so be careful not to place something in the old box that would break up the plastic....

We have looked a placing the converter into one of the empty boxes... but where its mounted already is good enough.

Option 2 is to go ahead and remove the existing old battery box... drill out the framework.. remove the plastic boxes.. and then use a piece of 2024 or 6061 sheet alu go ahead and blank out the hole... which access is through the inside of the trailer... one can use cherry max blind rivets to make it look factory again... and make sure you run a bead of sealant around the outside of the alu blank to seal against moisture... Cut a piece of fiberglass insulation... and another piece of sheet alu over the interior area.. no sealant required... completes the removal and replacement. Most of the group we know has gone this way with the transformation to GC-2 batteries...

In one case a owner who is a ham radio operator had us make a recessed box area... behind the existing door... so that he could open it.. and attach his radio coax to the exterior ham antennas' once set up... worked out great...although they do make through the wall coaxal fittings... this was just one way to use the area...
this then allows you to use the area under the front couch, etc... for interior dry storage leaving only the converter to rest at the factory location.

So their are several options to changing from the old type 24 bats to the new T-105's

Hope this helps...
the adventure contenues
G.M> WA6CDE