lipo battery safety

15 things every LiPo battery user should know

LiPo batteries are generally safer and more environmentally friendly than other R/C batteries like NiCd and NiMH. LiPo batteries have become the most common high performance R/C battery and are used in R/C cars, boats, planes, helis, multirotors and more. However, if charged, discharged, stored, maintained, or handled improperly, they can become extremely dangerous. This is a simple guide for safe LiPo battery ownership and use. This guide applies to all R/C LiPo batteries including all DJI Smart Batteries used in the Phantom 2 series and Inspire 1.

dji phantom 3 battery

1. Never charge, discharge, use, or store a damaged or puffy LiPo battery. Immediately follow proper disposal protocols.

2. Avoid purchasing used LiPo batteries. You never know what the previous owner did with them and they could already be badly damaged. “LiPo Battery Like New, Used Once” is usually a scam and should be avoided.

3. Always use a proper LiPo battery balance charger/discharger when charging and discharging your LiPos. It is crucial that all cells in a LiPo battery maintain the same voltage across all cells at all times. If the voltages across the cells deviate too much from each other (5mV ~ 10Mv), the battery can become unstable and dangerous. (Unless it’s a single cell LiPo, in which case you do not need to worry about cell balance).

4. Always use a fire proof LiPo safety bag, metal ammo box, or other fire proof container when you are charging, discharging, or storing your LiPo batteries. While LiPo fires are rare, they can happen incredibly quickly and can do a lot of damage. All it takes is an internal short circuit to set the battery off. There is no way to predict when it will happen. It does tend to happen more often when batteries are fully charged, being overcharged, or while being discharged, but it can happen to any LiPo at any time. Never fill the container to capacity with your batteries, always follow manufacturer recommendations on LiPo bags for how many mAh’s it can safely contain. It’s ALWAYS worth investing in an (under $10) explosion-proof LiPo bag or ammo can.




5. Do not use your flight case/travel case for long term LiPo storage. The foam and plastic in these cases can help spread a LiPo fire. Always use a fire proof container such as a metal ammo box or fire proof safe for storage.

6. Never leave your LiPo batteries charging while unattended. If a battery starts to become puffy, smoke, or catches fire you need to be able to immediately handle the situation. Walking away for even just 5 minutes can spell disaster.

7. A LiPo fire is a chemical fire. Always keep a Class D fire extinguisher nearby your battery charging/discharging and storage area. The battery charging/discharging and storage area should be free from any materials which can catch fire such as wood tables, carpet, or gasoline containers. The ideal surface for charging and storing LiPo batteries is concrete or ceramic.

8. Never overcharge a LiPo battery. Typically a full charge is 4.2v per cell. Never “trickle” charge a LiPo battery.

9. Never discharge a LiPo battery below 3.0v per cell. Ideally you never want to go below 3.2v per cell to maintain a healthy battery. 2.9v per cell and lower is causing permanent damage.

10. Never leave your LiPo batteries sitting around on a full charge for more than 2-3 days. If by the 3rd day you realize you are not going to use your battery today, you need to discharge your battery down to 3.6v-3.8v per cell for safe storage until you are ready to use the battery again.

11. Always store your LiPo batteries at room temperature. Do not store them in a hot garage, or in a cold refrigerator. Even though a cold battery has less chemical reaction taking place which can prolong its lifespan, taking a battery out from a cold fridge can cause condensation to occur on the inside of the battery, which can be very dangerous.

12. Always remember that heat is the number one enemy of LiPo batteries. The hotter your batteries get, the shorter their lifespan will be. Never charge a battery that is still warm from usage, and never use a battery that is still warm from charging.

13. Depending on how they are used, most LiPo batteries typically do not last longer than 300 charge cycles. Leaving them around on a full or depleted charge all the time, running them completely dead, or exposing them to high temperatures will shorten this lifespan dramatically.

lipo battery bag 14. LiPo batteries do not work well in cold weather. The colder it is, the shorter your run times will be due to the slowing down of the chemical activity within the battery. If it is below 14F (-10C), LiPo usage is not recommended at all. Your battery could cause your R/C vehicle to suddenly fail without warning in these temperatures.

15. Always pack your LiPo batteries in your carry-on bag and never in your checked baggage when traveling on an airplane. It’s the law.

-Written by Jessika Farrar

Jessika Farrar is the founder of ASG Aerial and specializes in aerial photography for personal and business use. Visit www.ASGaerial.com to learn more, or to book an appointment.

Jessika Farrar is also the Network Administrator for the S.W.A.R.M. Network where thousands of pilots from around the world volunteer their skills to help connect life saving drone technology with missing people. Go to www.SARdrones.org to learn more about how you can help.

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42 thoughts on “15 things every LiPo battery user should know”

  1. Hey Drone Girl, great article and especially important for guys who are not used to dealing with and caring for RC LiPos.

    Regarding tip #10 – very true…
    I found the lack of a decent way to discharge quickly to storage level quite a problem so I created a little gadget to do just that. I call it the Phantom Angel (because it protects your Phantom 🙂 ) More info at http://phantomangel.rocks

  2. Check your milivolts and megavolts. Capitals do play a role just as significant as temperature tolerances.

    And… when you fly on a cold day with a cold battery… doen’s the battery have a momentary increase in internal resistance?
    And what does, the increased internal resistance, cuase?
    Ain’t it… heat? Which, in turn, causes the internal resistance to increase?

    Worrie less, fly safer. Lipos catch fire only when poked, smashed, hammered, brutally overcharged or overdischarged.

  3. Great article, question is it ok to charge up a battery if it’s only at 65%. Or should I run it down to the 30 % then recharge after it cools?

  4. Lipo should not be stored in an air tight metal box, chem fire will not stop burning and can cause internal pressure until it’s released. Metal air tight ammo box in other words becomes a bomb. Maybe videos on YouTube about it.

    1. Unless you have a hole drilled into the ammo box for a pad lock already, if not you drill through the latch part on the sides straight threw the width of the box. Then you should be fine. I use one to store my rc car batteries..

    2. You can if you drill a hole threw the width of box on the sides into the latch. I had one from military school & it already had hole for pad lock. I use it to store my rc car batteries. =) I like it better than a lipo bag it had character. Hope that helps someone with one.

    1. pre used lipo battery would have lost its eligability to accept heavy wolt of power so that it will get heat inside while charging and it may chances to blast

  5. There are many things about Lipo battery that I don’t know. I had intention to buy an used Lipo battery last month. Luckily, I changed my mind and bought a new one.
    Thanks for sharing!

  6. Avoid purchasing used LiPo batteries. You never know what the previous owner did with them and they could already be badly damaged. “LiPo Battery

  7. If i chargey phantom 4 battery until lights go off, then attach charger again, how come it acts like the battery is low and starts charging agsin?

    1. The LED lights shouldn’t light up again after it’s charged. There’s something wrong with that P4 battery. P4 batteries won’t even let you “top off” the battery like the P3. Normally when a P4 battery is charged it won’t let you charge it any more, the LED lights will not light up again. It’s considered to be a “smart battery”. Visit phantompilots.com, you can learn a lot there.

  8. Jessica, I think your statement of 5 to 10mv is incorrect, by one decimal place. Usually the cell deviation between cells of .07 to .1 volts is when you should be concerned about the battery’s health. That’s 70mv to 100mv.

  9. LiPo batteries offer a wide array of benefits. But each user must decide if the benefits outweigh the drawbacks. For more and more people, they do. In my personal opinion, there is nothing to fear from LiPo batteries, so long as you follow the rules and treat the batteries with the respect they deserve.

  10. #13:

    ” Leaving them around on a full or depleted charge all the time”

    This is somewhat confusing. While in between runs chances are the battery will be depleted, thus lying around after the run.

    Then if preparing for a run, you’ll be charging the battery, then it’ll be lying around until the run.

    Any clarification?

    1. That’s how it is: do not store discharged nor fully charged (for days). It does make things more complicated. After use the battery should be charged/discharged to storage voltage. That means, only fully charge the battery when you know you’ll be using it (that day).

      Phantom 1 charger didn’t even have such charging option, so I’m using specialized multi purpose LiPo charger now. I don’t have smart batteries.

  11. I have a Yuneec Q500 4K. I don’t recall seeing in the manual exactly how you “discharge” the battery if you are not going to use it for a few days/weeks or longer.

    1. I don’t think you can since it’s a smart battery you have less control of it basically. I’m not sure Yuneec cared to design that as a feature into their product.

  12. I almost caught my house on fire tonight. Was charging 4 5000 22v lipos on the counter top. I knew that one of them had an issue with the balance port. I was getting a Vol Err but was getting other errors too. I decided not to charge with balance port but to just do a regular charge. An hour later my wife comes into my office to tell me one of the batteries is smoking. I ran to the kitchen, turned off the power supply, disconnected the battery and ran to the front door. It burst into flames while in the air after chucking it about 6 feet. 5 foot flame was coming out of both ends of the battery. Hose water did absolutely nothing. Lesson learned. All batteries outside now. If my wife had not seen the battery smoking, it would have been ugly.

    1. Very useful article. Should be compulsory reading for everyone using LiPos. What concerns me is there are now millions of drones out the all using LiPos, many in the hands of kids whose parents bought them for Christmas (guilty) and who have no idea at all of the potential for problems. Serious review of my own charging and storage regimes. Ammo boxes and lipo bags for storage and charging also a second CO2 fire extinguisher, won’t stop the battery but may be enough to suppress anything nearby that manages to catch. Disposal of bloated batteries not discussed here which is an oversight IMHO. I dishcharge with a balance charger down to storage levels, then am currently using a car light bulb to run absolutely flat. All done outside under metal bucket weighted down with bricks. I currently do this as soon as any sign of gas build up in a battery which is annoyingly frequent. Possibly my storage regime has been lax, leaving batteries charged too long.

  13. good info on LiPo batteries. A couple things I’d like add. BTW, I am an engineer and have worked a industrial/medical custom battery pack and charger design/manufacturing firm for several years. I have seen a Li-ion fire first hand in the lab and have designed dozens and dozens of battery packs and chargers for customers.

    1) Good tip on the vent in an ammo box. Had not thought about that. I get my drill out and vent mine. I did not stop to think they are water/air tight. When they burn, LiPos generate a tremendous amount of gas and flame. The electrolyte and other internal materials contain fuel AND oxidizer. Inside a latch ammo can, it’s a potential bomb that would make some nasty shrapnel.

    2) NEVER put water on a Lipo fire. You will create an explosion. The fire is so hot it will make steam which will then (potentially) disassociate into H2 and 02 and BOOM really big. “Smother the mother” – sand, dirt, etc. and get it the hell out of your house/shop/garage. Very likely it will set something else on fire.

    3) Good thing to have on hand: metal garbage can with a tight lid and fill it with sand or vermiculate (gardening section at Home Depot). Throw the pack in the can and slam the lid on. And use a hole saw to make a nice vent “chimney” in the lid.

    4) While you are at home depot getting that can, pick up several cheap 12″ ceramic floor tiles. They are what you want to put the pack on when charging or storing. Don’t have the pack on a combustible table/floor/shelf.

    5) Fundamentally, LiPos have a small margin when fully charged between max voltage/temp and over voltage/over temp. They have far LESS safety margin and have far MORE electrical energy when fully charged. Pretty much the same level of chemical energy when at low voltage but far, far less electrical energy to make a big spark from an internal short.

    Hope this helps everyone stay safe!

  14. 2. Avoid purchasing used LiPo batteries. You never know what the previous owner did with them and they could already be badly damaged. “LiPo Battery Like New, Used Once” is usually a scam and should be avoided.

    Such blanket statements do not serve the community well. You’re letting your paranoia off the few bad apples in society affect the many and by the comments, I see you’ve already affected some. There are plenty of reason a good seller can be selling a good used battery and as always, should be up to due diligence and not blanket statements.

    The rest of it is well done and useful info. Maybe a rephrase of #2 would be in order.

  15. Very nice tips! Also, if you plan on storing your LiPo batteries for extended periods of time then it s advised to discharge your battery to less then 50% charge and store in cool place.

  16. #12 you got wrong.

    It’s better to use warm lipos and it’s better to storage charge them when they’re warm too.

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