Wrapping Multisport 16000 in a carbon welding blanket

Does this sound like a sane idea? I ordered 2 18" square carbon welding blankets, one for each battery. I will run a split battery, one on each side of my seat on the trike, just like my A123 packs. The wrappings should retard the heat for a minute or 2 if fire occurs while riding. Otherwise the trike is charged on the brick porch outside the main house, possibly in a barbecue if I can make the batteries easily removable. Comments? Yep, I'm going to the dark side.
otherDoc

That carbon wrapping will be the wall between the batteries and the world? No aluminum case or other rigid case?

Thanks nobuo for the reply. No the fireproof wrapping will be surrounded by a Lexan shell. This provides some compression and resistance to puncture.
otherDoc

if you wrap the pack in an insulated blanket you only increase the chance of it reaching the critical temperature where it goes into thermal runaway when it is overcharged. if you are using a BMS or balancing charger it should not overcharge unless the JST plug makes poor contact and you are using a balancing charger like the BC 168 which can push high current into each cell.

Actually I am close to buying a BMS for 12S. I do use a good 12 S balance charger and Cellogs for alarms for riding. My voltage settings will be 4.15 high and 3.6 low. I think that if a cell is going to blow, the small amount of insulation compared to the large amount of fire protection is worth it. The carbon welding blanket is only 3/16 inch thick and is carbon weave impregnated with rock wool and a silicone adhesive. My batteries of any type never run over 1.5C for my 20 ah A123 or the new Multisport LiPo. I always respect your opinion, dnmun, but I think most battery encasements could raise the operating temp a bit, even masonite and tape. Those are certainly not fireproof. The carbon fiber can withstand a gas torch flame and melt solder on it with no damage. It may give me an extra 2-3 minutes if fire occurs while I am riding. Like all of us using LiPo, I hope I never have to use this extra protection. For home charging they will be outside in an alloy barbecue.
otherDoc

but they don't just blow up like you have been led to believe. you have to overcharge them enuff to raise the temperature to a critical level at which thermal runaway is initiated. none of this matters.

what matters is getting the pouches into orthogonal compression and keeping them cool and at low voltage until you need them. charging at high rates also shortens cycle life.

but none of this is relevant to safety. you have to protect against shorts on the output. that is what causes fires. not these imaginary explosions.

Well I hope you are right. I charge at about 1/4C and that's pretty conservative. I d/c at no more than 1.5C. And I have used Lipo for years when I could see well enough to fly electric glider models. None of this makes me feel safe, but I do want to take as much precaution as possible. I do know of at least 1 "spontaneous combustion" situation and that was John in CR. I am sure there were others.Jeeez if I keep writing like this I'll never get to use them. Thanks for the help and information, dnmun.
otherDoc

I did decide to put a hardshell (kind of) around the batteries and I used coroplast 2 layers cause I had a bunch of it around. Not quite as stiff as masonite, but surprisingly strong when held on with filament tape double wrapped. Now the batts will go into a blanket of carbon and then in their Lexan holders. First test hopefully Sunday. I am interested in the acceleration difference between 44 nominal volts and 36 volts from the A123 and, of course, not catching fire!
otherDoc.
otherDoc

Best approach, IMO, is always having the battery fairly easy to remove from the bike. Once flaming, forget it. But if it's just all hot and bothered, you can still remove it from the bike.

For example, you might have an accidental over discharge, and be looking at a pack that is puffing, hot, and might even be melting the shrink. This is when the compression material you used helps. Assuming you ride with gloves, you can still yank that sucker off the bike in case it does actually go off.

The compression boards, or even just coroplast battery covers can help protect the naked packs from the other problem that can cause a fire, chafing and puncture of the cells. I just cringe every time I see a picture of naked packs tossed into a bag or box, or worse, taped to a frame.

This easy off method also allows you to charge them away from the bike, in as always, a place you'd build a fire.

Thanks DM Dan. I am putting handles in both batteries and will charge them outdoors off the bike. There are 3 connections to the charge, the main Powerwerks connectors and the 2 balance connectors. they will be charged with a Thunder 1220 at about 4-5 amps. All connectors are polarized so they can't be hooked up wrong . (I hope) Pictures when the assembly is done.
otherDoc

Figured you'd be smart about it. I've never seen you post up a dumb idea. Lots of the time I post stuff, not talking to the thread creator so much as the noob also reading it.

My concern is that there is always a first time for dumb Ideas. DMD. I do try to run new ideas past you guys first, just in case!
otherDoc

I have had "spontaneous combustion" with used Makita packs as soon as I took the lid off. And had other fire problems with them. Yes before taking out of case ect. But with over 500 used recalled cells it's bound to happen.
So Doc just make it easily removable just in case. Remember Green Machine and he's S.F. pack fire. I would still put a alarm on them as they are so cheap as insurance. Good luck and how about those bosch packs has the boat landed ?

Thanks for the suggestions, Zip. Slow Boat is still in the water somewhere with my batteries. The new Multisports will have "grab handles" to yank and throw if I need to.
otherDoc