# [EVDL] Building a lithium battery box out of wood.



## EVDL List (Jul 27, 2007)

Lexan is really really nice!


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> Chris Zach <[email protected]> wrote:
> 
> > So I am working on the 20ah A123 cells and made a really nice battery
> > box out of 1/2 inch birch plywood. Very solid, snug, with padding inside
> ...


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## EVDL List (Jul 27, 2007)

Drill and tap holes for 4-40 screws.
Might need to get thicker stuff.
But u probably leave in an area where you can find a wholesale place.
You want lexan polycarb.
Do not get plexiglass!

Sent from my iPhone



> Chris Zach <[email protected]> wrote:
> 
> > On 6/25/2012 10:38 PM, Mike Golub wrote:
> >> Lexan is really really nice!
> ...


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## EVDL List (Jul 27, 2007)

> Chris Zach wrote:
> 
> > So I am working on the 20ah A123 cells and made a really nice battery
> > box out of 1/2 inch birch plywood. Very solid, snug, with padding inside
> ...


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## EVDL List (Jul 27, 2007)

> Christopher Zach <[email protected]> wrote:
> > ...
> > Given that lithium batteries carry their own oxygen much like magnesium
> > I wonder if there's anything one can do about a fire once it gets going.
> ...


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## EVDL List (Jul 27, 2007)

From: Mike Golub <[email protected]>
>Drill and tap holes for 4-40 screws.
>Might need to get thicker stuff.
>But u probably leave in an area where you can find a wholesale place.
>You want lexan polycarb.

Tapping polycarbonate is tough; it doesn't hold threads very well. When I make polycarbonate boxes, I use screws and nuts, or pop rivets.

>Do not get plexiglass!

Good advice. Plexiglass (acrylic) is glass-like, as the name implies. Crystal clear and brittle, it cracks and breaks very easily. And burns ferociously!

If you must use plastics for battery boxes, use polypropylene (which is what battery cases are normally made of). Very strong, and readily available in fire retardent sheets. Some electrical boxes are polypropylene.

Or polyethylene. It's not as strong, but has the best chemical resistance and is very easy to hot-air weld into boxes.

--
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

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## EVDL List (Jul 27, 2007)

From: Christopher Zach <[email protected]>
> Given that lithium batteries carry their own oxygen...

You're thinking of the Lithium-Cobalt cells. These are the ones that provide their own oxygen. They would probably keep burning underwater!

> I wonder if there's anything one can do about a fire once it gets going. 

A metal or other noncombustible box's job is to slow the fire, and keep it from spreading.

> Technically in a closed pack with thick aluminum around it like the 
> Prizm's any fire should self-snuff out

Aluminum has a fairly low melting point, so a fire may be able to melt its way out.

> A123 cells are supposed to not catch fire, but that's open for 
> discussion.

Lithium-Iron based cells are less combustible, but they still burn nicely. One cell in open air is pretty safe; but pack a bunch of them tightly in a box and they are still a fire hazard. I like to say LiCo cells are like a box of matches; while LiFe cells are like a box of kindling wood.

> I need something to act as a container for the cells 
> and I think even CALB cells have plastic in them somewhere.

Why not a plain old steel box?


--
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

_______________________________________________
| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
| 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
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## EVDL List (Jul 27, 2007)

I have had good luck with wooden boxes, just not plain wood. I built
the boxes using 5 layer quarter inch plywood and some oak pieces glued
and screwed together. I then painted them with a coating of fiberglass
resin. When that set I applied a couple of layers of fiberglass to the
outside. This strengthened the structure and protected the wood. There
was no exposed wood. I provided drain holes in the bottom for rinsing
and airflow. I also use a rubberized paint on the inside to provide a
little more protection from my NiCads electrolyte. These boxes have
been in my car for at least 5 years with absolutely no sign of
degradation. They are protected from sunlight but the bottoms are
exposed to the weather.

DAC



> Lee Hart <[email protected]> wrote:
> > From: Christopher Zach <[email protected]>
> >> Given that lithium batteries carry their own oxygen...
> >
> ...


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## EVDL List (Jul 27, 2007)

The steel box updated with perhaps aluminum angle as an exo-skeleton and
panels of galvalume sheet metal which is like galvanized but with aluminum
plating instead of zinc over the steel. a coating of truck bed spray
coating over a good primer will protect it
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> Lee Hart <[email protected]> wrote:
> 
> > From: Christopher Zach <[email protected]>
> > > Given that lithium batteries carry their own oxygen...
> ...


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## EVDL List (Jul 27, 2007)

> Christopher Zach wrote:
> 
> > On 6/26/2012 1:02 AM, Lee Hart wrote:
> >> But again, it is terrible stuff to make high voltage electrical boxes
> ...


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