thick & durable wide diameter heatshrink, any suggestions?

[voicecoils]

I'm interested in providing more protection for my 36v10Ah Headway packs by heatshrinking them in a thicker and less brittle heatshrink.

Any heatshrink experts out there?

What materials should I look for that will provide some impact/vibration protection for the cells, electrically insulate and be durable? The more 'clamping' force it provides once shrunk is a benefit too.

Cheers!

 

[liveforphysics]

Pick the largest size you can find that will still shrink down onto your cells. It only gets thicker the more it shrinks down, so this gives you the thickest layer you can get for a given type.

Shrink wrap is extruded and naturally at it's shrunk diameter. They expand it over a long mandrel to enlarge it into the size it is when you buy it. When you hit the natural size, it won't shrink any smaller, but it is able to be worked by hand to a degree and held in a position until it cools, and then tends to keep that position.

Multiple layers of the thickest, largest diameter you can find that will has a natural diameter smaller than the cells. That would give a coating optimal for physical protection. This will be much like putting a little jacket on each cell, so you should de-rate the C-rate of your jacketed cells.

Best Wishes,
-Luke

 

[voicecoils]

Ah, that's all very good info, thanks Luke! Any specific material types you can suggest for a non-brittle end result?

I'll be shrink wrapping around the whole pack (12 cells + bms), not around individual cells but will keep the thermal concerns in mind.

I'm almost tempted to shrink wrap the cells individually since the jacket is thin and the cans are 'live' but I don't want to go overkill on thermally insulating them for the sake of over electrically insulating them...

 

[rkosiorek]

heat shrink of any dimension may help to keep your pack tied together and provide electrical insulation. but it does not provide any protection at all from impact.

for impact protection you still need some kind of solid hard plastic/metal/wood container. for vibration you need some kind of good quality open cell foam or rubber padding.

for padding i like to use neoprene. the same kind of stuff they use to make divers wet suits. actualy, i buy it from a local dive shop that makes custom wet suits. at one time i had the dive shop make up a neoprene tube with closed ends that i could slide the pack into. after a couple of accidents i decided that an additional hardshell is still needed to help prevent dinging and denting the cells.

rick

 

[gogo]

A sectioned tire inner tube? It would have the advantage of being reusable if you needed to take it off.

 

[chet]

There is heat shrink used to winter wrap boats down at the marina.
There is heat shrink wrap used to package goods down at the cannery.
There is heat shrink tape available at the electric supply.
There are a lot of large sizes of heat shrink tube available someplace.

 

[ZapPat]

There are a lot of large sizes of heat shrink tube available someplace.

The *only* place I've managed to find very large heatshrink tubing is at ebikes.ca, but I would like some to find some other sources and different kinds. Do you mind sharing about where's the "someplace" you mention for big heatshrink?

 

[voicecoils]

There are a lot of large sizes of heat shrink tube available someplace.

The *only* place I've managed to find very large heatshrink tubing is at ebikes.ca, but I would like some to find some other sources and different kinds. Do you mind sharing about where's the "someplace" you mention for big heatshrink?

I'm in the same boat as you, ZapPat. I have a meter of the ebike.ca stuff, but like the Headway wrap, it's fairly thin and brittle.

I'm keen to find something more pliable/rubber-y like the narrow diameter stuff easily found & bought for cabling.

 

[ambroseliao]

Hey Voicecoils,

Exactly what size is your pack? Length, width and height would be useful info...

Ambrose

 

[317537]

Do two layers.

Start with one just big enough to fit over your wire. Then use a larger one as sugested above. "The more it shrinks the thixker it gets". Obvious really, the things you learn along the way. cheers!

You could use insulation tape underneath. Ive even apoxy glued ac cable insualation over wire joins.

 

[dontsendbubbamail]

Bubba uses Lexan and duck tape from HD. It seem that any time I heat shrink something all pretty, a reason comes up to undo it. If I ever get to the day that I have the final, last final, final final design, then maybe I will heat shrink it.

Bubba

 

[dnmun]

even the final last fix, last final sealed for life, never going back, shrink wrap will cause the inverse murphie's law to occur. kinda like the quantum mechanics thing about how no matter what, there is that zero phonon allowed by quantum mechanics in response to recoil energy hitting the atom with the gamma ray emission, the sound that makes no noise.

murphie's inverse law: seal it up and it will die, the one loose solder weakened sense wire contact will break and pull off the cell pole,

even when you double check, triple check ad infinitum, there is always another inverse murphie's law consequence. usually caused by an excessive over abundance of caution.

 

[northernmike]

3M makes nice stuff, in a wide variety of sizes. I've seen it at many an electrical trade supplier's counter.

 

[GGoodrum]

Batteryspace used to sell the rubber-like 3M stuff, in 9"/230mm widths, which was great. I loved using it on my packs because it did provide a bit of shock protection. Here's what it looked like:








For whatever reason, they stopped selling the stuff, and wouldn't give me their source. I looked high and low for another supplier, but couldn't find one. I ended up finding a source for the regular black PVC shrink, in ta 9-3/4"/248mm width, but I had to buy a 500' roll in order to get it. I have enough now to pretty much last me forever. If any body needs any, PM me.

Anyway, it works well, and looks good. I usually double up on it, to make it a bit thicker. Here's what my latest LiPo packs look like:

View attachment 2

View attachment 1




The larger one is Turnigy 20C 12s3p 44V/15Ah and is in series with the smaller one, which is 6s3p.

-- Gary

 

[chet]

There are a lot of large sizes of heat shrink tube available someplace.

The *only* place I've managed to find very large heatshrink tubing is at ebikes.ca, but I would like some to find some other sources and different kinds. Do you mind sharing about where's the "someplace" you mention for big heatshrink?

I said someplace because I can only find 2" diameter. But i have larger sizes shipped with battery from China.