Use kevlar tape to protect battery?

[cwah]

Hello there,

I've seen this kevlar protection video:
[youtube]4x8AJYDrFlU[/youtube]

It's puncture resistant and can protect from impact. So maybe I can do the same thing with my battery?

I could wrap my battery pack with kevlar tape:

http://www.ebay.co.uk/itm/50mm-Kevlar-Tape-3m-/170859777503?pt=UK_CarsParts_Vehicles_BoatEquipment_Accessories_SM&hash=item27c8094ddf#ht_761wt_789

And protect the battery from vibration with packing foam:
http://www.ebay.co.uk/itm/Multi-Pack-Foam-Packing-Foam-x-10-sheets-/110899902429?pt=UK_Packaging_Materials&hash=item19d22637dd#ht_1991wt_862


So the battery protection would be like this:

It would be much lighter than standard metal box. And easier to do than custom box as it's just tape you wrap around the battery.

Good idea?

 

[Punx0r]

Unfortunately, it won't offer any crush protection, which AFAIK is the main danger to pouch cells.

I suppose you could impregnate it with resin to address this, but glassfibre would be much cheaper and be plenty good enough.

I've handled those generic aramid cloths and their main characteristic is slash resistance. The weave is loose, so puncture resistance isn't greater. It'll also fall apart if cut and pulled in the "wrong" direction.

The fibre and (most significantly) weave in a ballistic/stab vest is very different (I've seen inside a few).

IMO I'd save your money

 

[kfong]

Use a mix of fiberglass and an outer layer of carbon fiber and epoxy for a light weight composite box that is also fireproof.

 

[cwah]

Would that be better if I use this carbon fiber sheet from HK?

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9781

I can then glue them together with epoxy:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=12584

 

[Ykick]

Cut to size/shape and attach to bricks with filament tape. I use thin 1/8" Masonite brand board to help protect my bricks from puncture and crash damage. Those Carbon sheets look even better...

 

[cwah]

So use carbon fiber from HK and wrap it with fiber tape?

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9375

 

[Drunkskunk]

Yes.

But even better would be to make your own. Other than special sissors (or extreamly sharp hair sissors) its no diffrent than working with fiberglas. Or if you've ever done paper mache as a kid, its the same idea, and just as easy.

I've got a carbon/Kevlar composit bashguard I made for one of my bikess. the new bike I'm planning Carbon/Kevlar covers for the battery. That tape is the wrong stuff to use, but some basic Kevlar cloth would work. Or Carbon fiber, or Fiberglass, or a combination of any 2 or all 3 depending on what features you want.



http://www.fibreglast.com

 

[dogman dan]

The sheets look good to me. They could be assembled with fiberglass and resin in the corners, or drilled and screwed much like you'd use my choice, 1/8 aluminum sheets. I just happend to find old road signs in my garage when I bought the house. So that was my choice, free stuff.

 

[cwah]

Drunkskunk, I've been to your website but there is so many different item I don't know which one to use?

What would be the best for lightweight protection on a 12kg battery pack? I thought the one from HK was great. And what tape should I use then?

Dogman, I prefer not to use metal because it's too heavy. Fiberglass or acrylyc are more lightweight. What fiberglass or resin can I use to stick that together? Is it some sort of resin glue?

 

[MadRhino]

Kevlar and fibergalss will be heavier than Alu, only carbon fiber makes sense to me as a replacement for my Alu protections

 

[cwah]

So fiber glass from HK. What product is the best to glue them together?

 

[dnmun]

how will you get access to the battery after you do this?

 

[cwah]

I'm planning to glue it enough in order to have an open bod. I wouldn't glue everything lol

 

[smudger1956]

So fiber glass from HK. What product is the best to glue them together?

Cyanoacrylate adhesive is good for 'joining' together Polyester Fibre Glass sheet/Epoxy Glass sheet/Carbon Fibre sheet, and even the..what looks like Carbon Fibre sheet that has one layer of CF and the rest Glass weave then pressed with Black resin to make it all look like Carbon Fibre sheet .....
But..Cyanoacrylate has no sheer strength, Micro Balloons and resin mixed to a 'filler' form is very good for reinforcing the joints, or use resin and Glass or CF tape.

 

[dogman dan]

A huge part of my choice to use wood and aluminum to build my boxes is easy dissasembly. Had a pack overdischarge and puff inside your battery box yet?

When you do, you sure as heck won't be sliding that thing out of the box. I just pull a dozen screws and the side cove comes off allowing very quick removal of that smoking reeking puffed up piece of junk.

Makes sense to a dumbshit like me, who will end up making a lipo mistake.

 

[cwah]

Thanks Smudger. I've seen you're from UK too? Any link to ship any of these at good price in the UK?

Dogman, I'm planning to use foam all around my battery. So if it ever puff I should be able to remove the foam at the same time as the battery. What's the weight of your aluminium box? I think a battery box of more than 1 kg is too much for a bike.

 

[smudger1956]

Thanks Smudger. I've seen you're from UK too? Any link to ship any of these at good price in the UK?

Dogman, I'm planning to use foam all around my battery. So if it ever puff I should be able to remove the foam at the same time as the battery. What's the weight of your aluminium box? I think a battery box of more than 1 kg is too much for a bike.

Sorry cwah,Never imported HK CF, have a look on Google uk / eBay, loads of CF around.

 

[cwah]

I mean the glue to be used. I think I'm going to get the CF from HK. However I'm not sure what to buy as glue? If you can point me to any product reference I'd do the remaining search. Just a bit lost for now as I've never created a box before.

 

[smudger1956]

I mean the glue to be used. I think I'm going to get the CF from HK. However I'm not sure what to buy as glue? If you can point me to any product reference I'd do the remaining search. Just a bit lost for now as I've never created a box before.

Ah..right....search for Zap Thin/Med Cyanoacrylate, VitalBond Thin/Med Cyanoacrylate to name a couple, and Cyanoacrylate activator, and have a gen up on using Cyanoacrylates.
It is really good for fast fabrication, but you only get one go,it bonds virtually instantly, so fitment and alignment of parts must be spot on.

 

[docnjoj]

Also CA is quite brittle when used as the only bonding agent with CF. In our F5E gliders a ways back we had to bond a sheet of balsa above the core where the carbon was with epoxy. Much more flexable and shock resistant. The CA may be better today as this was my hobby 20 years ago. Those wings really flexed but never cracked.
otherDoc

 

[cwah]

So if I buy this:
http://www.ebay.co.uk/itm/Vital-Bond-MEDIUM-Cyanoacrylate-Industrial-Super-Glue-/370540642958?pt=UK_Crafts_Cardmaking_Scrapbooking_Glue_Tape_EH&hash=item5645f1828e#ht_2896wt_922

I can safely bond the HK carbon fibre sheet? Should be strong enough for a 12kg battery?

 

[atom1025]

Tack it with CA then use shoe goo aka GOOP to rienforce the corners. Shoe goo is crazy strong when cured.

Gorilla glue(no water) can be worked into weaves and gives a firm yet flexible shell. Just keep squeeging the surface for an hour till glue is no longer tacky. Allow to cure then sand smooth.

 

[cwah]

So I get:
- HK 1mm carbon fiber sheet: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9781
- Vital Bond MEDIUM Cyanoacrylate : http://www.ebay.co.uk/itm/Vital-Bond-MEDIUM-Cyanoacrylate-Industrial-Super-Glue-/370540642958?pt=UK_Crafts_Cardmaking_Scrapbooking_Glue_Tape_EH&hash=item5645f1828e#ht_3032wt_1021
- And protect the corner with shoe glue: http://www.ebay.co.uk/itm/Triple-Pack-Mini-Shoe-Goo-Clear-3-x-Tubes-5-32ml-0-18oz-Shoe-Glue-Adhesive-/251048861917?pt=UK_Crafts_Cardmaking_Scrapbooking_Glue_Tape_EH&hash=item3a73ada0dd#ht_500wt_798

And I should have a strong and light box that is shock proof for my 12 kg A123 pack?

ps: Not sure if I need to add gorilla glue to all of that.

 

[cwah]

I've found this seller able to cut polycarbonate sheet to the exact dimension I need:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=400147307924&ssPageName=ADME:X:RTQ:GB:1123#ht_1752wt_905

It's going to be way simpler than carbon fiber. And also cheaper.

Do you think 2 mm thick polycarbonate box is enough for a 12 kg A123 battery?

 

[smudger1956]

I've found this seller able to cut polycarbonate sheet to the exact dimension I need:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=400147307924&ssPageName=ADME:X:RTQ:GB:1123#ht_1752wt_905

It's going to be way simpler than carbon fiber. And also cheaper.

Do you think 2 mm thick polycarbonate box is enough for a 12 kg A123 battery?

Hi cwah, all depends on how big the box is, 2mm polycarbonate is a bit 'floppy' do you plan to reinforce, or support the box ?
Gluing, or rather bonding polycarbonate is a bit fraught,it's all solvent based stuff.

Cheers
Smudger