I crashed my drone and the battery was ejected, causing some noticeable scratches. I wonder how I can better protect LiPo battery from crashes and did some research. Here’s what I’ve found.

To protect LiPo battery from crashes, always mount your battery onto an anti slip pad. You can also wrap the batteries with a polyolefin heat shrink tube, PET bottle, or bicycle tube. If you have extra budget, mount a TPU battery landing protector underneath your LiPo. Those steps will reduce the likelihood of battery ejecting in crashes, at the same time protecting your battery from impact and damages.

Let’s dive in on how to protect your LiPo battery from crashes so that you can get the most out of your battery.

Why Should I Protect the LiPo Battery?

A crashed quadcopter with ejected LiPo.
LiPo batteries can be easily damaged from impact in crashes. Photo by dan lundmark / CC BY 2.0

Undoubtly, LiPo batteries are dangerous, and need to be well-taken care of. A damaged LiPo pack becomes even more dangerous. I am sure you don’t want to burn your house charging a damaged LiPo pack.

LiPo batteries are expensive investments, you would want to make sure that they are well protected. If it is seriously damaged from a crash, you will need to change a new battery for safety reasons.

If you don’t want to burn your money with each crash (which is unavoidable), make some effort to protect your LiPo battery.

How to Protect LiPo Batteries

LiPo batteries are usually damaged when it is ejected after a crash. Hence, the ideas on protecting the battery revolve around preventing ejection and reducing impact if the battery pack is ejected. Below are some of the best LiPo battery protection methods that you can use to protect your crashed LiPo.

Anti Slip Pad

The surfaces of our LiPo battery and the drone are smooth. Upon impact, the LiPo batteries can easily get ejected from your drone. 

There are 2 potential outcomes that can be caused by ejection of the battery. For one, it might fly out and hit a hard object or the spinning props. That can cause direct damage to the LiPo battery itself. Or, you will need to spend hours searching for the LiPo, and might still not be able to find it. 

When the battery is ejected, there is also a slight chance of your props cutting the battery cables too.

To prevent that from happening, it is best to lay an anti slip battery pad onto your drone, and tie your LiPo battery onto the pad. With the help of Velcro strap, the anti slip pad grips the battery firmly and prevents your battery from ejecting.

You can get the anti slip pad and battery strap from the link below:

Strap : GetFPV | Banggood

Anti slip pad : GetFPV | Banggood

Wrapping the Battery

Heat Shrink Tube

If you want to protect your LiPo battery from crashes, why not give it armor? One thing that you can do is heat shrink your LiPo pack with a shrink tube. You can either use polyolefin or PVC shrink tubes

Polyolefin tubes are thicker and give more protection to your LiPo. It can help to absorb some impact from crashes. You will have to expect some extra weight though. In addition, polyolefin shrink tube grip better on the anti slip battery pad than its PVC counterparts.

In case you aren’t aware, polyolefin is a group of chemicals that includes polyethylene. So, if you see heat shrink tubes labeled as polyethylene, they are polyolefin.

Meanwhile, PVC shrink tubes are thinner and lighter in weight. But it offers less protection to the LiPo battery. You might need to add additional layers to strengthen the protection.

When you are selecting a shrink tube, make sure its flat width is slightly bigger than the sum of height and width of your LiPo. Depending on the materials used, the shrink tube can shrink to half or 1 third of its original size. Hence, it is OK to get a slightly bigger shrink tube. That makes it easier for you to insert the LiPo into the tube.

For instance, if your LiPo’s size is 78 mm x 39 mm x 41 mm (L x W x H), the flat width of the required shrink tube should be at least 80 mm (39 + 41). If your shrink tube has a 2:1 shrink ratio, you can use up to 160 mm width tube (but you shouldn’t, since bigger shrink tubes are more expensive and take longer to shrink to the right size).

To wrap your battery with a heat shrink tube, you will need a hot air gun (GetFPV | Banggood). You can also use a hair dryer but the whole process will be slower since the amount of heat generated is rather limited. Never use fire because that may damage your LiPo, or ignite it!

It is a good idea to remove the battery label before heat shrinking and paste it back on the new heat shrink tube. Otherwise you will need to manually label your LiPo.

You can also put some rubber bumpers underneath the 4 corners of your LiPo before heat shrinks. The rubber bumpers can help to absorb some impact upon crash/landing, while also helping to hold on to the Velcro strap when the LiPo slips. That will reduce the chances of LiPo from ejecting. 

Bicycle Inner Tube

Bicycle inner tubes are a good alternative to heat shrink tubes. It is cheaper and can be free if you can get a used inner tube from a bicycle shop. The inner tube is also thicker, which provides better protection to your LiPo. But of course, it will be heavier than shrink tubes.

The main challenge here is to get an inner tube with a flat diameter slightly smaller than the sum of the width and height of your LiPo. Once you have it, cut it into the length slightly longer than your LiPo. Then, stretch the opening of the tube and slot in the LiPo (the end with the cable first). Put your LiPo on the desk, standing, and slowly push the tube downwards.  

Before putting in the battery, you can apply some heat onto the inner tube using a hot air gun so that you can stretch the tube easier.

Remember to relabel your batteries so that you can identify them.

PET Plastics

If you can’t find a right-size shrink tube, you can use a PET bottle instead. 

Prepare a PET bottle and cut it to the length slightly longer than your LiPo. Cut some cardboard into the size of your LiPo battery. 

Place the cardboard into the PET bottle as a mold and start to heat up the PET bottle using a hot air gun. The PET bottle will start shrinking to the size of your cardboard mold. You can use the stove fire but a hair dryer will not work.

Once the PET shrinks to the right size, remove the cardboard and put in the battery. Trim the opening of the PET to prevent the LiPo cable from being cut by sharp edges. Then, carefully heat the opening so that it folds inward

Lastly, wrap a few rounds of tape around the front and back of the PET. That will serve as the footing which helps to absorb some impact.

You can refer to the original post of this guide here.

Learn FPV at FPV Unlocked.

TPU LiPo Landing Protector

There is this TPU (thermoplastic polyurethane) LiPo landing protector designed to protect LiPo mounted underneath the drone. You can buy it or print it if you have access to a 3D printer.

Depending on the design, you can either mount it underneath the frame of your drone and put your LiPo in between, or simply tie the landing protector under the LiPo using a Velcro strap.

There are a few benefits of using the LiPo landing protector. First, it is hassle-free. You just need to tie it underneath the battery without modifying the battery itself. Second, you only need 1 of this, if your batteries are of similar sizes. There is also a place on the LiPo landing protector for you to secure your balance cable so that it doesn’t get cut by the props mid-flight.

The design of the landing protector reduces the likelihood of your LiPo from ejecting upon crash. It also gives you some advantage in taking off because your drone can lean forward to produce more forward thrust. 

The landing protector also protects your LiPo from normal landing. The obvious downside though, is the additional weight.

Last Words

I hope the methods shared above are useful in helping you to protect your LiPo batteries from crashes. Don’t forget to check out my guide on how to take care of your LiPo batteries to get the most out of them. Happy flying!