Plastic vs Metal . Battery boxes

Plastic Or Metal ???

  • Plastic

    Votes: 0 0.0%

  • Metal

    Votes: 0 0.0%

  • Wood

    Votes: 0 0.0%

  • Other.. please explain below !

    Votes: 0 0.0%
  • Total voters
    0
  • Poll closed .
Ypedal

Ypedal

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Ok.... Here goes.

I have a nice new piece of Makrolon Polycarbonate and was going to build up a Battery box for one 36v 8AH pack configured into 2 rows of 15 D cells.

Tonight, walking the dog with the neighbors, talking about how this was taking shape.. we decided to try a metal box instead.

Metal :

- Acts as a heat-sink and allows the pack to cool
- Conductive, in the unlikely even i wipe out.. :twisted: It could crush and somehow short the pack out.. - bad things..
- Nice and shiny.. light-weight.. won't crack..
- etc

Plastic :

- Retains heat as an insulator
- Transparent, I would need to paint the inside or something.
- NON conductive, safe...
- Difficult to work with.. i have access to the tools however.
- etc
 

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Wood rules :D :

-light
-cheap
-many options
-easy to find, cut, drill, shape, join, glue, sand and paint
-good insulator
-nice for bonfires
 

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but the thickness needed to support the pack, will not fit between the cranks the way i need it to.
Click to expand...

Must be a heavy pack! The 1/8th inch oak plywood I use easily supported 40lbs of lithium cells, packing, solder, etc. It was my aluminum back rack that cracked under the weight.

Same stuff I used in this pic (some of the small wood braces were thicker, but I don't think they needed to be):
 

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I voted metal as it's meant to go on the bike, but...

cardboard + duct tape + backpack = rules
Bike feels so much lighter/handles way better.
 
Other.
Plastic AND Metal.
You know those plastic things in pizza boxes that keep the box from collapsing onto the pizza? Imaging something like that(made of metal) with the prongs inserted into the batterypack through the empty spaces between the batteries in order to conduct hot/cold. The Solid part the prongs attach to is outside the plastic case exposed to the wind for cooling if heat while riding is an issue or imagine that it goes into a compartment of it's own into which you can insert hot pockets to conduct heat to the batteries if driving in cold weather and you need to keep your batteries warm. This second compartment can have a slider to open or close airholes. You could even insert COLD packs to cool the batteries while charging.

Call it the LIETR Leblanc Internal External Temperature Regulator (lighter).

This way you have the insuating properties of being totally enclosed by plastic
 
Wood is for termites.


I like the plastic in metal approach. A metal box on the outside with a thin but puncture resistant plastic on the inside just to prevent shorts. I used 1/16" polycarbonate for safety insulators on a one of my scooters. The vibration from bumps in the road really beats the inside of a battery compartment.
 
Wood is for termites.
Click to expand...

:lol:
That explains why my battery boxes seem to be shrinking!

I'm a genuine hick from the Ory-gon sticks, not some plastic Californian. Wood works good for me. :)
 
http://video.google.ca/videoplay?docid=-4749862029616241264

I shot this video last year, you may have seen it already.

I'm mounting knobies to the Norco this season with a 4012/408 instead of the 409/406 that's on it now..

The batteries need to be mounted very securely as i plan to try and jump this thing, soft bags or fragile mounting is not an option.

For a comfort bike it would be fine.... but this application is a bit more demanding. :p
 
i like Lesss's idea.
except
i'd use aluminum for 2 round sides and plastic/wood for the 2 terminal sides. that way it cools, and insulats the wiring
 
I think even a small fan will help with the battery heat issue.
That's what Honda and Toyota use in their hybrids.

It would be nice if it was somehow thermostatically controlled so the batteries can warm up when the outside air is really cold.
 
The thermal transfer but electrical insulating stuff they use for the fet fitting kits
what is it :?:
does it come in sheet form :?:
That would be ideal for a metal batt case as a heat sink to the pack.
AT the moment i use nylon batt bag but thinking about metal case for security + heat sink.
 
Hmm... Good idea.

The stuff is some kind of silicone rubber with a fabric embedded in the rubber. The fabric increases the strength. Silicone is a good heat conductor.
 
Could also do a metal case then cover the metal on the inside with plastic. spray on or paint on liquid plastic that solidifies ( something like locktight).
 
Mine is a combination of HDPE plastic, nylon, reinforced cloth, metal, velcro, balsa wood, and glue :) hehe

Hey, how come we cain't vote? Wots with that? :?
~KF
 
I use a metal kid's lunch box. It holds my 15s3p 9ah pack with room for wires. I lined it with 1/4" packing foam (from some package I received). Stuff that into the e-bike kit battery bag. Works very well, but I'm not sure what I'll do if/when I get more lipo. I'll need a custom fabricated metal container. I don't weld.
 
Well..since its been bumped my votes for Fiberglass, can form any shape is very light resins can be colored so painting isn't even required...

KiM
 
Aluminum test equipment box lined with styrofoam for DayGlo Avenger. Box is a side-pannier for cargo, too.

Insulated (thin flexible styro sheet) lunchbag for The Velcro Eclipse, wiht velcro straps pinned under aluminum medical equipment faceplates for the mounting plate to the water-bottle mounts. Bag is in triangle; straps are inside bag to secure battery to plate. Bag itself is just there to keep the battery from being exposed to direct sunlight to heat it up, and also to kinda keep the bike from being quite as ugly as some of mine. Also to keep down the number of huge unnecessary contraptions on it. ;)

No battery boxes on CrazyBike2--they're just hose-clamped into the central triangle. :)
 
Ypedal said:
This goes back to 2007 !!!... yikes !
Click to expand...

Sometimes ES feels like some kind of time machine. It's weird.

marty said:
Plastic is the future.
Click to expand...

Well it's the future now. Not sure how many plastic battery boxes there are on ebikes, but there would have to be quite a lot, I'd imagine.

Personally, I prefer metal, specificaly 6.5 mm alum checkerplate used as the bikes structure. Here's one I prepared earlier :D
 

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Lipo REQUIRE METAL BOX !!

They not just insulate against explosion or fire but also have the strengh to keep the lipo cells compressed and avoid them to inflate!!.. and as well keep internal resistance low!

Lipo cells tend to inflat when they are charged and to deflate when they goes low or empty.

I observed that in my aluminum box ( 12 lipo 6s 5000mAh) for total of 1.3kWh little box.

When i knock on the box when they are full charged, the box sound like ROCK or concrete!.. and when the cells are low or discharged, the box sound alot less stiff.

it's like knock on your box for gauge level!.. lol

1/8 thick aluminum is perfect.


Also to avoid risk of short circuit or fire that travel from one cell to the next.. i added FR4 ( pcb) material between each cell row and around the inside of each box panel


Doc
 
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