Project: Create a cheap but safe battery box

[cwah]

Hello all,

I'd like to create a battery box for my 74V12AH Zippy compact battery pack.

I've already created a box for my A123 20AH battery. It's all wood made, quite strong but a bit bulky and not very safe:

As you can see, I used 3 custom steel tie to compress the cells. Apparently pouch cell needs a high level of compression to allow good working order.

I'm planning to do the same thing with my current battery pack:

 

[cwah]

Battery pack is 130x150x150mm:

I'm thinking to maybe use aluminium to have to less bulky and safer in event of fire? What about 3 mm aluminium sheet I would weld?

 

[averhamdave]

I'm just about to build another battery enclose to take 6 lipos but I'm planning on using a "plastic enclosure" (see eBay) and laying the 6 packs in a line inside the enclosure. It will sit on the rack within the top bag of a new Raleigh pannier set I have just bought from Argos.

What's puzzling me about your picture is I know its 70v and so that means 20 lipo cells in series, presumably doubled up to give 10ah? Are the 3 black objects on top of the Zippy packs single cells? - thereby making up 39 cells?

Just curious

 

[cwah]

It's a 2*9s + 2s zippy compact. I had a dead cell in one of my zippy compact, so I extracted the cell and divided the pack. They are all 4AH cells with 3 in parallel.

I end up with a 74V12AH pack, which should be enough to do 20km on my 1000W continuous Brompton bike

 

[cwah]

I had a start on my wood box:

Added plastic protection on the corner and have an area to fit a compression strap.

Next is to get a carbon fiber vinyl:
1.27X0.3Meter 3D carbon fiber vinyl film/ carbon fibre sticker (50X11.8"/127X30cm) 13 color option FREESHIPPING car sticker-in Stickers from Automobiles & Motorcycles on Aliexpress.com

And get some heavy duty cable tie to create a compression strap:
24.0 Inch 4.6mm x 600mm Best 304 Stainless Steel Cable Ties-in Cable Ties from Electrical Equipment & Supplies on Aliexpress.com

 

[banbury frank]

Hi Looks Great you need Kindling wood to start a good fire ????????

Frank

 

[cwah]

Ideally I'd like to use epoxy glass sheet and aluminium, but it's too expensive. I've seen 4mm aluminium sheet with epoxy glass sheet shipped to france over 50gbp.

Wood is free lol

 

[Biker44]

I end up with a 74V12AH pack, which should be enough to do 20km on my 1000W continuous Brompton bike

How many batteries can you pack together before you get over-heating problems?

 

[cwah]

Not sure to understand.. Overheating from battery, motor or controller?

Anyway my mac motor and 12 fet controller should handle it. With such a big pack battery would barely get get warm at 1000W which is about 1C