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LiPo Batteries, How do you restrain them??

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Lowpuller

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I am using a LiPo Battery in my AV Bay. I am currently restraining it with nylon wire ties......but I have concerns.

It is difficult to remove and replace for charging.

If I charge it on the sled, as I have been, I risk losing all my electronics if it catches fire.

I am also concerned about damage to the "wrapper" from a hard or even mild landing.


What do you do???

ImageUploadedByRocketry Forum1480296938.711842.jpg

Just FYI, I am only using these 9Vs for ground testing. I only fly Duracells or Energizers.
 

timbucktoo

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I use tie wraps same as you. I remove them for charging. Tie wraps are cheap!
Haven't had any damaged but they're cheap enough that I have many spares.
 

OverTheTop

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I use Velcro between the LiPo and sled, and a cable tie or two to hold the battery to the Velcro. The velcro takes the majority of the force, with the cable ties just holding down the battery to the Velcro.

AltsCompleted.JPG
 

Thorfire

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Zip ties work. When I get time, I'd like to 3D print some sleds that would do a better job.

1480297387408.jpg
 

Lowpuller

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Overthetop

Please post more pics of that AV Bay, very sweet.
 

fyrwrxz

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I line them all up on the work bench and sternly tell them to behave while shaking my finger at them. It's important not to smile while you do this. Most of them get it if they have a charge.
 

MikeyDSlagle

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On one of my rockets I vacuum formed me a cover that attaches to my sled and holds the battery and wires. Had issues with other things on that sled and in the end used zip ties. The cover worked great, would've been better had I not tried to use it to manage the wires. Round 2 will be better.

I have also used mirror hangers, kaplow clips or a piece of DIY z bar.
 

dixontj93060

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+1 to the Velcro, or I more often use industrial strength two-sided foam tape. The majority of holding force comes from these solutions and then a bit of electrical tape (or a fairly loose zip-tie) is all you need.

If you've ever driven R/C cars or trucks, LiPo's can take quite a lot, just don't short or puncture. Yes, it could happen in a crash or CATO, but a normal profile flight or maintenance (charging) is really not problem.
 

Worsaer

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I line them all up on the work bench and sternly tell them to behave while shaking my finger at them. It's important not to smile while you do this. Most of them get it if they have a charge.

+1 !!! <huge grin>
 

Coop

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I framed out a battery holder out of square stock, once. Was fairly simple and worked well enough on my L3 flight.


Later!

--Coop
 

rharshberger

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I typically build a thrust shoulder/box around the battery using scraps of wood and then I can zip tie the battery in without cinching them too tight. In the two photos below the blocks are visible.

L3Build117.jpg AvBay1.jpg

Edit: notice that the JST connector on the Lipo is zip tied in such a way that it can't accidently come apart under acceleration.
 

mpitfield

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I use tie wraps same as you. I remove them for charging. Tie wraps are cheap!
Haven't had any damaged but they're cheap enough that I have many spares.
X2, they are so inexpensive to buy in bulk and easy enough to take off or install. You are wise to know to remove them for charging as it would be a shame to lose your AV-bay and electronics from a Li-Po fire. Even if it's unlikely, it's just not worth the risk when looking at it from a risk/reward perspective. That is at least with my AV-bay designs, which accessibility and serviceability are designed into them.
 

Reinhard

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Currently, I use a small 3D printed "cup" that fits the battery. I don't have a photo at hand, so there is only this rendering. It contains cutouts for the cables. On the backside, there are two stubs, that lock it into corresponding holes on the altimeter sled. Cable ties (I also consider them consumables) are used to hold everything together. The (admittedly small) advantage over a cable tie only solution is that it prevents shear loads on the cable ties. This methods is more valuable for components with less regular shapes. I've used it for an GPS module once, that would have been awkward to mount otherwise.

battery holder.png

Reinhard
 

TKnox

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I built battery boxes on the back of the sled out of square stock with covers that are screwed in with wide- head servo screws.ImageUploadedByRocketry Forum1480352519.814899.jpg

Epoxied on the sled with covers on.
ImageUploadedByRocketry Forum1480352597.915901.jpg
 

KenECoyote

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I'm using these (learned about releasable zip ties from years with RC cars):



Currently ~$7 on Amazon. I use two ties on each 9V in a cross pattern and haven't had issue yet. Always check after zipping that they lock.

BTW - you can actually release even those zip ties that aren't "releasable"...use a tiny screwdriver or the tip of a pen knife and pry up the locking mechanism. I've done this since I can remember and as long as you don't mangle up the locking mechanism and you're in a pinch, you can reuse it (again, check that it locks and if unsure at all, don't use it).
 
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scsager

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I am using a LiPo Battery in my AV Bay. I am currently restraining it with nylon wire ties......but I have concerns.
A crash DID damage the lipo INSIDE my Mobius camera. - So I completely understand your concern.

I am starting to think it might be risky to continue using any LIPO's that have crashed - no matter how they were restrained.

I am currently using Velcro "One Wrap Thin" cable ties. I use them exactly like regular zip ties - same idea.

The advantages are easier to release, and much more "surface-area" (1/2 inch wide) in contact with the battery.

These are NOT standard "fuzzy" velcro. This is a thinner more "plastic" style of velcro, and sticks to itself very strongly.

https://www.amazon.com/dp/B001E1Y5O6/?tag=skimlinks_replacement-20

velcro-one-wrap-thin.JPG
 
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Tonimus

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I bundle my batteries together with electrical tape, and secure that bundle to the board with a velcro strap.
 

Lowpuller

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I've had a similar idea, basically place padding under the nylon wire ties to increase the surface area, or make a 1/2" wide Velcro wrap but the wrap would be difficult to fit into my sled.
 

dixontj93060

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I bundle my batteries together with electrical tape, and secure that bundle to the board with a velcro strap.
What size battery is that?

If you use tiny batteries (which you should so you don't blow FET drivers), you won't need special padding for zip ties. The zip ties should be lose, not snug on the LiPo perimeter. They don't need to be tight as a 10 to 15 gram LiPo is so little mass it is mostly held in place by double-sided tape.
 

KenRico

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I usually use dbl sided tape and nylon ties. .

.. But I charge them on the sled , so i only take them off when i have to use them somewhere else.

Kenny
 

caveduck

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Small batteries, the most righteous 3M VHB double-sided tape (9xxx series, not the consumer stuff), and a cable tie for insurance on the 2S ones. I charge them in place with a smart charger and appropriate limit settings.
 

Tonimus

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What size battery is that?

If you use tiny batteries (which you should so you don't blow FET drivers), you won't need special padding for zip ties. The zip ties should be lose, not snug on the LiPo perimeter. They don't need to be tight as a 10 to 15 gram LiPo is so little mass it is mostly held in place by double-sided tape.
Those are four 2s 800mah batteries.

To the OP, I had those batteries come in at about 40 mph. The payload bay accordioned and the dissipation there saved the batteries. They'll be okay coming in a little hot.
 

Lowpuller

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Nmartin

Are you using the pallet straps as protection from the zip ties?
 

JoeG

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Like Overthetop and Dixontj I use Velcro for holding and cushioning. Zip ties only tight enough to keep battery from pulling away from velcro. I've used this system on everything from Mach 1.6 rockets to 40% scale R/C aircraft and large and small batteries. Never had a battery come loose or damaged from anything other than an all out crash. Snip zip ties and remove for charging. I do charge LiFe batteries without removing though.
 

nmartin

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Yes - the pallet strap protect from the zip ties. I use the pallet straps a lot for protection. I have had zip ties cause damage from being to tight
 
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