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Why Is My Traxxas LiPo Battery Swelling?

RC cars are amazing pieces of technology and Traxxas is far and away the most popular RC car manufacturer. Their RC cars are well known not just for being the fastest (the XO-1) but also for being the most durable as well. 

Almost all RC cars run on battery packs and LiPos are the most powerful of those so they are often used in the best quality RC vehicles. However, sometimes those batteries will begin to swell up and knowing why this is happening to your battery is very important. 

Traxxas LiPo batteries will swell up when they need to be replaced. If you have a LiPo battery that has started to swell you should immediately stop using it and replace it with a new one. 

There are a variety of reasons why your LiPo battery might begin to swell including: 

  • Overcharging
  • Running it down too much
  • Using the wrong charger
  • Old Age

Each of these can have an effect on your Traxxas battery. Sometimes batteries have simply been used a lot and there isn’t anything that you did wrong they are just ready to be replaced. No matter what caused the battery to swell you should NEVER use a swollen battery as it could explode! 

Once a battery has started to swell it is time to head to your local hobby shop or Amazon and get a new LiPo battery. There are a variety of LiPo batteries available on Amazon and you can compare them by clicking here

In the rest of this article we will discuss the reasons that LiPo batteries can swell up as well as try to answer some common questions that people often have. If before we get to that you want to see what could happen if you continue to use a LiPo battery once is has swollen up you can watch the video below. 

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Reasons why Traxxas LiPo batteries swell

There are many different reasons why your LiPo battery might swell up. We will cover the four top reasons that this happens below. 

1. Overcharging

This can happen to anyone but can happen a lot easier if you are not using the proper battery charger. You should always use a battery charger that is designed for LiPo batteries and not just assume that the one that you have will “be fine”.  

LiPo batteries require special chargers to prevent them from getting overcharged as well as to balance the cells properly. Most brands (Traxxas included) will have LiPo chargers that are designed specifically for charging LiPo batteries. Don’t ever use a charger that is not designed to work with LiPo! 

2. Running it down too much 

This is a similar issue to overcharging but in the opposite direction. Most RC cars will have a shut off when the battery is low to prevent you from depleting them too much but not all RC cars will. Be sure and check to see if your model does because if it doesn’t then you will need to manually keep track of it so you don’t run the batteries down too far. 

3. Using the wrong charger

As mentioned earlier you should only use a charger that is designed for LiPo batteries with LiPo batteries. Even a slow charger could damage your LiPo batteries if the cells get out of balance so the only charger that you should ever use is one specifically designed for LiPos. 

Traxxas makes a special battery charger (found here) that will work with both LiPo and NiMH batteries but most chargers will only work with one type so make sure that the one you are using is designed to work with LiPos. 

4. Old age

Over time your LiPo batteries will quite simply just wear out. This is true no matter if they are made by Traxxas or made by any other manufacturer. Traxxas makes great quality cars and batteries so their batteries will likely last longer than generic ones but they will also wear out eventually. 

When LiPo batteries wear out they will often not be able to handle charging or running properly. You will normally notice that the battery pack has begun to swell first and as long as you stop using and charging it you should be able to prevent a fire (like in the video above)!

Once a battery starts to swell even a little bit you should immediately stop using it, dispose of it properly, and get a new one. The last thing any of us want is for our RC vehicle to catch on fire or explode because we were too cheap to replace the battery. 

How do you fix a swollen LiPo battery?

If you find that your LiPo battery has begun to swell your first thought might be trying to fix it. Afterall, it seems like a problem that could be relatively easy to fix and if you just skimmed and didn’t read all of the article above you might not know any better. 

When a LiPo battery starts to swell there is no “fix” for it. You will want to immediately dispose of it to prevent a fire from happening or the battery from exploding! 

The LiPo battery swelling is telling you that it is time for it to be replaced. There is no fix for a swollen battery besides disposing and replacing it. 

Is a swollen LiPo battery dangerous?

There are all sorts of videos of batteries exploding on Youtube and almost every one of them is from a swollen LiPo. 

Swollen LiPo batteries can definitely be dangerous and could lead to a fire or explosion injuring you as well as possibly burning down your house! If that isn’t dangerous I don’t know what is!

You certainly don’t want to burn down your house while trying to charge or use your RC car (try explaining that one to your spouse)! Quite simply if the battery has started to swell get rid of it and get a new safe one. 


It should be abundantly clear by now that once you realize your LiPo battery has started to swell you should dispose of it and get a new one. You could likely get another use or two out of it if you are careful but by doing so you are risking your RC car catching on fire or the battery exploding while you are charging it. 

In my opinion the risk of a fire and destroying your RC car or even your home just isn’t worth getting a couple more uses out of the battery pack especially since you can get LiPo batteries for between $20-$30. 

Once your Traxxas LiPo battery begins swelling take it outside (removing the fire risk) and let it cool down. You will then need to dispose of it properly (which will vary based on your location) and get a new one.