PRW
100 kW
what are ideas for the best way to protect a battery from rattling round and movement within a battery enclosure (like with Stealth Bomber, Phasor, etc)? Chunks of polystyrene, bubble wrap, ?
thanks
thanks
Best material for battery impact shock absorption?
- Thread starter PRW
- Start date
BatteryMan
10 mW
- Joined
- Oct 10, 2016
- Messages
- 23
How about a giant mouse pad that you can cut and custom to your enclosure?
https://www.amazon.com/Perixx-DX-1000XXL-Gaming-Mouse-Pad/dp/B00EG7WB8C/ref=sr_1_1?ie=UTF8&qid=1482086218&sr=8-1&keywords=giant+mouse+pad
https://www.amazon.com/Perixx-DX-1000XXL-Gaming-Mouse-Pad/dp/B00EG7WB8C/ref=sr_1_1?ie=UTF8&qid=1482086218&sr=8-1&keywords=giant+mouse+pad
PRW
100 kW
good idea - got me thinking about a latex mold, which would be expensive - so what about a memory foam or latex pillow, cut to suit?BatteryMan said:
beast775
100 kW
Memory foam is sold in alot of stores, its easy to cut imprints if you take your time and have a sharp blade.ive found the most important part is the fit of the outer surface [compression] snug, but same all the way around.no movement is key.
DAND214
10 MW
I use a yoga pad. Got mine a Aldi, but there here and there, not all the time.
Dan
Dan
Any foam you use must be dense closed-cell type. Anything with open cells will not hold it's shape and just crushes under the weight of whatever is on it, and the pack can bounce around after that.
I use old mousepads, and thick blue closed-cell foam, in my 50cal ammocan packs; no issues with wire damage or cell problems so far (EIG pouch cells in one, EM3EV pouch A123 split pack in the other). I just make sure to pack it tight enough that I have to force the packs down into the cases.
I use old mousepads, and thick blue closed-cell foam, in my 50cal ammocan packs; no issues with wire damage or cell problems so far (EIG pouch cells in one, EM3EV pouch A123 split pack in the other). I just make sure to pack it tight enough that I have to force the packs down into the cases.
dogman dan
1 PW
Some movement is more or less inevitable, so I like to start with a very tightly fitted box of coroplast, usually old political signs.
The idea whatever material you choose, is to tape it up so tight in the box that the battery cannot move in the box. This provides a bit of crush zone around the corners, and enough space so a screw head, random chunk of gravel, or whatever cannot abrade the batteries shrink wrap. I do this with both lipos, and 18650 shrink wrap packs.
Then once you pack the box in the container, just about anything can be used to take up the extra space. Even a tightly stuffed old rag can do the trick. The coroplast scraps can also be used as flat shims.
One thing I have not tried, the spray foam in a can. Used for packing lots of things, you've seen it,, foam sprayed in a bag, inside the box.
Scraps of Styrofoam can also cut and fit to custom shapes.
Closed cell foam works great too. This is the stuff used in anti fatigue pads you stand on, mouse pads, wet suits. etc. This is what I use the most generally, the pads you stand on. They make great soft rear fenders too.
Open cell foam will crush,, but if you pack it in so tight it's already crushed, it can work a lot like a rag or other material you can stuff in tight.
The idea whatever material you choose, is to tape it up so tight in the box that the battery cannot move in the box. This provides a bit of crush zone around the corners, and enough space so a screw head, random chunk of gravel, or whatever cannot abrade the batteries shrink wrap. I do this with both lipos, and 18650 shrink wrap packs.
Then once you pack the box in the container, just about anything can be used to take up the extra space. Even a tightly stuffed old rag can do the trick. The coroplast scraps can also be used as flat shims.
One thing I have not tried, the spray foam in a can. Used for packing lots of things, you've seen it,, foam sprayed in a bag, inside the box.
Scraps of Styrofoam can also cut and fit to custom shapes.
Closed cell foam works great too. This is the stuff used in anti fatigue pads you stand on, mouse pads, wet suits. etc. This is what I use the most generally, the pads you stand on. They make great soft rear fenders too.
Open cell foam will crush,, but if you pack it in so tight it's already crushed, it can work a lot like a rag or other material you can stuff in tight.
craneplaneguy
10 kW
Every time I get a package, when I open it up I am always eager to see what type of packing material my shipper has used. I now have a wide selection of various foams....used for various purposes, including battery padding. Those damn foam peanuts are useless though! So, keeps your eyes open, I didn't have to go out of my way to get good padding, it came to me, free!
FWIW: according to a friend who has been in the poly urethane spray foam business for 35 years, the product was first developed by the Germans during WW2, initially the thought was to use it for raising sunken ships. It worked, displacing the water and providing flotation, but it was such a PITA to clean out it was deemed impractical for that purpose. I love the stuff, it's keeping me warm right now as a matter of fact, but I don't think I'd use it in a battery pack. Too good of insulation for one thing, and once compressed it pretty much stays compressed, I want a closed cell that recovers.
FWIW: according to a friend who has been in the poly urethane spray foam business for 35 years, the product was first developed by the Germans during WW2, initially the thought was to use it for raising sunken ships. It worked, displacing the water and providing flotation, but it was such a PITA to clean out it was deemed impractical for that purpose. I love the stuff, it's keeping me warm right now as a matter of fact, but I don't think I'd use it in a battery pack. Too good of insulation for one thing, and once compressed it pretty much stays compressed, I want a closed cell that recovers.
PRW
100 kW
great, thanks for all the ideas
MadRhino
100 GW
The best impact protection is self destructive. I mean, for equal space and shock to absorb, nothing beats layered destruction. For this reason, open cell foam does better than closed cell, but it does work only once. :wink:
Yeah, but two problems with it:
It collapses on the first vibrations/bumps (depending on weight/surface area/etc),
and
it doesn't keep the pack from moving around inside the box once any of it has crushed, which means further impacts will be even worse as the pack bounces around inside, and further crushes the "impact protection", etc.
That's why the closed cell stuff works better for this purpose.
It collapses on the first vibrations/bumps (depending on weight/surface area/etc),
and
it doesn't keep the pack from moving around inside the box once any of it has crushed, which means further impacts will be even worse as the pack bounces around inside, and further crushes the "impact protection", etc.
That's why the closed cell stuff works better for this purpose.
dogman dan
1 PW
Layered 8)
That's why it starts with the coroplast for me. 3mm or so of very stiff protection first, that can crush if needed, like you drop the pack on a corner. ( I also put a nylon strap handle on the box btw) Its like the crush zone that protects you in a car. stiff, but if you need it, it crushes and absorbs impact. Or it can sit on a screw head sticking up 1mm, and never wear though to the pack. A bolt head can be layered with another sheet of coroplast, with a hole cut for the bolt head. Then if the box is harsh metal, more protection between the box and the coroplast.
I have often used some cushy stuff on the bottom of the box as well, like a mouse pad or some yoga mat inside the bottom of the box. This is done when the battery will always ride in the bike oriented that way.
That's why it starts with the coroplast for me. 3mm or so of very stiff protection first, that can crush if needed, like you drop the pack on a corner. ( I also put a nylon strap handle on the box btw) Its like the crush zone that protects you in a car. stiff, but if you need it, it crushes and absorbs impact. Or it can sit on a screw head sticking up 1mm, and never wear though to the pack. A bolt head can be layered with another sheet of coroplast, with a hole cut for the bolt head. Then if the box is harsh metal, more protection between the box and the coroplast.
I have often used some cushy stuff on the bottom of the box as well, like a mouse pad or some yoga mat inside the bottom of the box. This is done when the battery will always ride in the bike oriented that way.
spinningmagnets
100 TW
I agree with DanD214 above...YOGA PAD...available very cheap in volume at any large sporting-goods athletic-supplies store. Various thicknesses.
Ykick
1 GW
Yoga mat's good idea/improvisation. Combining Coroplast is good stuff too.
I’ve been very pleased with scraps of foam tile flooring -
http://www.foamtiles.com/tiles/12-eco-soft-tiles.html?utm_source=google&utm_term=&utm_campaign=&utm_medium=cpc&utm_content=s_pcrid_50436501581_pkw__pmt__pdv_c_&gclid=CKi__JD4gtECFU5MDQodxKsG7w
I’ve been very pleased with scraps of foam tile flooring -
http://www.foamtiles.com/tiles/12-eco-soft-tiles.html?utm_source=google&utm_term=&utm_campaign=&utm_medium=cpc&utm_content=s_pcrid_50436501581_pkw__pmt__pdv_c_&gclid=CKi__JD4gtECFU5MDQodxKsG7w
MadRhino
100 GW
Yep, open cell foam is very good to protect batteries in a crash, but it does need to be replaced often because it doesn't need a hard impact to start degrading.amberwolf said:Yeah, but two problems with it:
It collapses on the first vibrations/bumps (depending on weight/surface area/etc),
and
it doesn't keep the pack from moving around inside the box once any of it has crushed, which means further impacts will be even worse as the pack bounces around inside, and further crushes the "impact protection", etc.
That's why the closed cell stuff works better for this purpose.
Now I am not using any foam, for I have built the battery bag alu box mounts to bend and destroy in a crash. The Lipo bricks are tight in the bag stiffen with CF sheet inserts, that is tight in the alu box with quick release pressure lock, and the box is mounted on the bike with self destroying brackets that can absorb a hard crash with 1" self destructive compression.
As a result, I have better crash protection for the Lipo bricks, and no more shaking noise like I had when using foam.
Hummina Shadeeba
10 MW
have a pic? Do you use any "fill" between cells?
do any of you add a lot of compression to lipo cells?
someone mentioned silicone but wrote it off as expensive and i think you should rethink it. i think it's a great cheap fill that will/can last forever. smooth-on.com or similar stuff can be gotten, a pint for 23$. won't stick to the cells. a solid container with the cells suspended inside and then rubber poured in I wonder if it would get better range years later with less vibrations. Or similar with the tightly compressed cells encased in the carbon box as above?
and compression and holding the gas from expanding is good?! I think I've read compression is fine but maybe they mean just adding pressure on the sides and allowing gas can collect at the ends. entombed lipo, how will it fare?
this is a surprise to me, it is super hard silicone and cheap:
https://www.smooth-on.com/products/mold-max-60/
maybe too hard to fully entomb.
do any of you add a lot of compression to lipo cells?
someone mentioned silicone but wrote it off as expensive and i think you should rethink it. i think it's a great cheap fill that will/can last forever. smooth-on.com or similar stuff can be gotten, a pint for 23$. won't stick to the cells. a solid container with the cells suspended inside and then rubber poured in I wonder if it would get better range years later with less vibrations. Or similar with the tightly compressed cells encased in the carbon box as above?
and compression and holding the gas from expanding is good?! I think I've read compression is fine but maybe they mean just adding pressure on the sides and allowing gas can collect at the ends. entombed lipo, how will it fare?
this is a surprise to me, it is super hard silicone and cheap:
https://www.smooth-on.com/products/mold-max-60/
maybe too hard to fully entomb.
PRW
100 kW
just came home to this...
2 yoga mats, one kids flooring, and 2 pieces of Coroplast! One of the dangers of mentioning to my wife that I need some stuff - but she got it mostly at Good Sammy's, so all good.
2 yoga mats, one kids flooring, and 2 pieces of Coroplast! One of the dangers of mentioning to my wife that I need some stuff - but she got it mostly at Good Sammy's, so all good.
Ykick
1 GW
LMAO....
MadRhino
100 GW
I set them lipo bricks tight but not compressed. They spec to expand 10 to 15% normally, and I believe compression would increase the risk of leaking gas. I guess that when you are building a very large battery, it could be compressed because the total C rate would be high enough to prevent expansion. Mine are beaten close to their max discharge rate everyday, and most do finish their utility life pretty swollen.
Adamlivi
10 mW
I'm building an aluminum/carbon fiber battery box. Planning on trying inflatable padding via a 700c thornproof tube with presta valve protruding for inflation/deflation. I'll post pics if successful.
tomjasz
1 GW
PRW said:just came home to this...
2 yoga mats, one kids flooring, and 2 pieces of Coroplast! One of the dangers of mentioning to my wife that I need some stuff - but she got it mostly at Good Sammy's, so all good.
Great woman! She's a keeper!
PRW
100 kW
tomjasz said:PRW said:just came home to this...
2 yoga mats, one kids flooring, and 2 pieces of Coroplast! One of the dangers of mentioning to my wife that I need some stuff - but she got it mostly at Good Sammy's, so all good.
Great woman! She's a keeper!
haha - the cost is, every time I build or buy myself a bike, I have to get her one too! At least I always have someone to ride with...
Lurkin
100 kW
PRW said:
And it gets expensive too!
Interesting has anyone done any testing with these materials to see how flammable they are/ whether they react with the battery chemistry when it fails (not a chemist, but I've been thinking about this for a while)?
The mousepad stuff doesn't appear to react to leaking RC LiPo, if that's what you mean. I have an ammocan pack of that stuff, padded with the high-density blue closed-cell foam as well as mousepads, and neither one has changed in any noticeable way from some leaking cells in at least one of the puffy packs. (other than the smell of whatever electrolyte it has absorbed). The shrinkwrap and wires haven't reacted with the foam either, AFAICS.
Similiarly, an EIG pack that's also padded with such foam has not shown any problems with foam or cell casings or wires reacting with each other, though none are leaking so couldn't say about that part.
Both packs are a few years old; I'd guess it's been around a year that some of the cells have been leaking in the RC LiPo pack (been puffy longer than that). (no, I am not using it at present :lol
As for flammability, I knwo the blue foam is highly flammable, and the mousepad stuff probably is, too but have never tested that.
Similiarly, an EIG pack that's also padded with such foam has not shown any problems with foam or cell casings or wires reacting with each other, though none are leaking so couldn't say about that part.
Both packs are a few years old; I'd guess it's been around a year that some of the cells have been leaking in the RC LiPo pack (been puffy longer than that). (no, I am not using it at present :lol
As for flammability, I knwo the blue foam is highly flammable, and the mousepad stuff probably is, too but have never tested that.
tomjasz
1 GW
yes, mine just took over my last build.PRW said:
