Re: [EVDL] Fw: Re: best battery racks
From: Dave Hymers <[email protected]>
> I'm new to battery box building... I was tentatively planning on
> using 2" angle iron... and a product called Omega bond used for
> making cheap aluminum signs (it's 2 sheets of aluminum and a
> composite rubber center) to line the inside of the boxes, probably
> sealing with some sort of caulking (and venting with PVC pipe/fans)
What quality level are you seeking, and how long do you want it to last? That has a LOT to do with the approach taken.
The classic cheap way is to bolt or weld together a frame made of angle iron (old bed rails etc.), with a plywood box. Quick and easy, but if you put flooded batteries in it, it will decompose into junk in a few years. The acid mist attacks the steel and rots the wood. Paint only delays it a bit.
It's not much more work to do a better job.
- Batteries are heavy, and dangerous if they get loose in a crash!
Build the box to secure them solidly enough so they will stay in
place even in a roll-over.
- They are also a shock hazard! You might not touch them, but kids,
pets, mice, and curious bystanders will. Fully enclose them,
just as you would your home's fusebox or electrical panel.
- Don't use bed rails. It is junk steel; weak and hard to drill
and weld. Mild steel is easier to work with, but rusts easily.
Stainless steel is better, but expensive and hard to work with.
- Don't expect any paint or coating to stop the acid. There will
always be pinholes or cracks. The acid will get underneath, and
rust the steel underneath it. You do not want major structural
members rotting away where you can't see them!
- Instead, build a battery box to sit in your steel rack. Its job is
to absolutely stop the acid from reaching the steel, electrically
insulate the batteries from ground (so you don't get shocks or
ground faults), and thermally insulate them (so your range doesn't
change in hot or cold weather).
- Thus, the box can't be metal, or at least must have a nonmetallic
liner. Plastic, fiberglass, or phenolic insulating board are good
choices. For flooded batteries, it should be water-tight, like a
bathtub, with a drain located so the runoff won't go on anything
important. Here are some options (best first in my opinion).
Method #1: Make the box out of styrafoam. Fiberglass it inside
and out with glass cloth and epoxy resin.
Method #2: Same, but polyethylene or polyurethane foam, fiberglass
cloth, and polyester resin (polyester disolves styrafoam).
Method #3: Make a box out of sheet plastic (polyethylene,
polypropylene, ABS, etc. Solvent-weld or hot-air-weld corners
as appropriate for each type of plastic. If thick and strong
enough, use as-is. If thin and weak (for example, made with
flexible plastic sheets), use it as a liner inside a box made
of metal or some other strong material.
- Flooded batteries must be vented to the outside. If they vent
inside the car, the fumes will stink and slowly destroy your
interior.
Whew! Sorry it's so long-winded. Hope this helps
--
Those who say it cannot be done should not interrupt the one who is
doing it. -- Chinese proverb
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net
_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
From: Dave Hymers <[email protected]>
> I'm new to battery box building... I was tentatively planning on
> using 2" angle iron... and a product called Omega bond used for
> making cheap aluminum signs (it's 2 sheets of aluminum and a
> composite rubber center) to line the inside of the boxes, probably
> sealing with some sort of caulking (and venting with PVC pipe/fans)
What quality level are you seeking, and how long do you want it to last? That has a LOT to do with the approach taken.
The classic cheap way is to bolt or weld together a frame made of angle iron (old bed rails etc.), with a plywood box. Quick and easy, but if you put flooded batteries in it, it will decompose into junk in a few years. The acid mist attacks the steel and rots the wood. Paint only delays it a bit.
It's not much more work to do a better job.
- Batteries are heavy, and dangerous if they get loose in a crash!
Build the box to secure them solidly enough so they will stay in
place even in a roll-over.
- They are also a shock hazard! You might not touch them, but kids,
pets, mice, and curious bystanders will. Fully enclose them,
just as you would your home's fusebox or electrical panel.
- Don't use bed rails. It is junk steel; weak and hard to drill
and weld. Mild steel is easier to work with, but rusts easily.
Stainless steel is better, but expensive and hard to work with.
- Don't expect any paint or coating to stop the acid. There will
always be pinholes or cracks. The acid will get underneath, and
rust the steel underneath it. You do not want major structural
members rotting away where you can't see them!
- Instead, build a battery box to sit in your steel rack. Its job is
to absolutely stop the acid from reaching the steel, electrically
insulate the batteries from ground (so you don't get shocks or
ground faults), and thermally insulate them (so your range doesn't
change in hot or cold weather).
- Thus, the box can't be metal, or at least must have a nonmetallic
liner. Plastic, fiberglass, or phenolic insulating board are good
choices. For flooded batteries, it should be water-tight, like a
bathtub, with a drain located so the runoff won't go on anything
important. Here are some options (best first in my opinion).
Method #1: Make the box out of styrafoam. Fiberglass it inside
and out with glass cloth and epoxy resin.
Method #2: Same, but polyethylene or polyurethane foam, fiberglass
cloth, and polyester resin (polyester disolves styrafoam).
Method #3: Make a box out of sheet plastic (polyethylene,
polypropylene, ABS, etc. Solvent-weld or hot-air-weld corners
as appropriate for each type of plastic. If thick and strong
enough, use as-is. If thin and weak (for example, made with
flexible plastic sheets), use it as a liner inside a box made
of metal or some other strong material.
- Flooded batteries must be vented to the outside. If they vent
inside the car, the fumes will stink and slowly destroy your
interior.
Whew! Sorry it's so long-winded. Hope this helps
--
Those who say it cannot be done should not interrupt the one who is
doing it. -- Chinese proverb
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart-at-earthlink.net
_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
