MAAA Wingspan

22 Anybody who uses LiPo’s like me will eventually encounter a puffy or swollen battery. The first question that usually comes up is “What should I do?” This article is all about what causes that swelling, what to do when it happens to one of your LiPo’s and what I have learnt….. or tried to about the 3rd place getter on the periodic table… Are Swollen LiPo Batteries Dangerous? Yes. Next question. (they are in third place on the periodic table, this alone backs up this statement). Seriously though, there are so many examples of puffed batteries that started a fire that this shouldn’t even be a question now. That doesn’t mean that every battery that is puffed is going to explode as soon as you use it, but it does mean that a high enough percentage of them are going to be dangerous that it isn’t worth the risk. What Causes LiPo Batteries to Puff Up? Gas generation in lithium ion batteries is a normal thing and we have all had one that has looked like this. Even if you don’t work your battery hard, the normal everyday use of your battery will generate gas through a process called electrolyte decomposition. The electrolyte decomposition occurs even faster if you over-discharge a battery or overheat a battery. So, what is electrolyte decomposition? To put it simply, a battery is made of three things: the anode, the cathode and the electrolyte. The cathode and the anode are the positive and negative terminals on your battery, and the electrolyte is a chemical inside the battery that allows charged ions to flow from the anode to the cathode during discharge (and the reverse during charging). Electrolyte decomposition is what happens when that electrolyte chemically breaks down. So, in a LiPo’s battery, as the electrolyte breaks down you end up with lithium and oxygen. This forms lithium oxide on the anode and cathode (depending on whether you are charging or discharging). But what you also end up with is excess oxygen that doesn’t adhere to the anode or cathode. This excess oxygen is part of what causes a battery swell. And, oxygen likes to burn (like many historical events where there was a kaboom). Other JOE ‘WISE’ WANGID: EDUCATIONAL A HOT TIP FROM JOE: DISCARD DANGEROUS LIPO’S