We are always getting questions about charging LiPo batteries so we decided to list our top 10 dos and don’ts for charging your battery packs. Now because almost all e-power flyers are using LiPo, LiFe or Li-Ion battery packs, we are only dealing with those battery packs in this article. The first thing is to make sure that you are using the correct charger for your pack; for example, LiPo is not the same charging as LiFe or Li-Ion. Be sure you’re charging on the right battery chemistry and the correct cell count and then follow these tips.
DO CHARGE ANY LIPO, LIFE OR LI-ION AT 1C
All packs of this chemistry can be charged at 1C and should be charged at that rate. A 1C charge does take a bit of time but this charging rate is the easiest on your packs and will not cause undue heat, which is your battery’s enemy. This charge rate will give your battery its longest life and let the balancing port do its job. For example, a 3400mAh battery charging at 1C would have the charger set at 3.4 amps charging rate.
DO ENCLOSE YOUR BATTERY PACK IN A BATTERY BUNKER OR A LIPO SACK DURING CHARGING
Having everything contained only makes sense and I cannot see any reason not to have your charging pack in one of these products. If your charger comes with a temp probe, be sure to have it inside the sack. If your battery should need rapid removal from the shop, you can easily do that if everything is in a fireproof sack.
DON’T LET YOUR BATTERY GET BELOW THE MINIMUM VOLTAGE
This is more of a flying issue than a charging problem, but it needed to be addressed, so here it is. When flying, try not to let the battery drain until the speed control starts shutting off, because in most cases unless you changed it, the battery is near its minimum voltage. Then you have extra time on the pack and more draining until you land the aircraft. You can set the minimum speed control cut-off above the pack’s minimum voltage so as to have some extra time to set up for landing. I like to time my first flight until the speed control cut-off and then set my timer on the transmitter to a minute before that. On all flights after that, I land right after my transmitter timer goes off.
DON’T CHARGE YOUR BATTERY AT MORE THAN 1C, UNLESS THE MANUFACTURER APPROVESNewer batteries are advertising a higher charging rate and this can save a lot of time when needed. I try not to charge even these batteries at the higher ratings if I don’t need to, although I do this at the field or at an event, when I need the faster rate to get in the air sooner. But other than that, I always use the slower rate at home because this will extend the battery life.
DON’T EVER LEAVE THE ROOM WHEN YOUR BATTERY PACK IS ON THE CHARGER
This is the number-one safety issue when charging that almost everyone violates. But it is also the number-one thing that will prevent any minor mishap from becoming a major incident. Every fire that you read about that happens from charging packs started when the person was not in the room. You need to be there to monitor your pack while it is charging. If you have to leave the room, stop the charger and disconnect the battery from the charging wires. Then when you are back in the room start up the charging process again, it will not just take a shorter time to complete than it would have.
DO CHARGE YOUR PACKS WITH A STORAGE CHARGE WHEN THEY ARE NOT BEING USED FOR MORE THAN A WEEK
This will keep them balanced and stable. When battery packs are shipped new they have a storage charge on them, and there is a reason for that. A storage charge keeps the individual cells from drifting and going out of balance. A full charge has a better chance for the cells to drift further from each other than a storage charge does. I almost always give my packs a storage charge and then the night before, top them off with a full charge.
DO CHARGE YOUR BATTERY PACK ON A FIREPROOF SURFACE
If something bad should happen and a pack starts to vent, having it on a surface that will not burn keeps it from spreading. Be sure to also have some airspace around the battery pack to prevent anything else from becoming involved.
DON’T EVER CHARGE WITHOUT A BALANCING PLUG CONNECTED
There is no reason to charge without balancing a pack. This keeps all the cells even, allowing them to work together with less stress on each. A balanced pack will always outlast a pack that has never been balanced. Keep this in mind-almost every new charger has balancing ports for keeping the packs balanced.
DO INVEST IN A SMOKE DETECTOR ABOVE YOUR CHARGING BENCH
This is really a cheap investment for your shop and it covers more than just the charging table. Long before any battery vents, it will smoke, and it will smoke a lot. This will alert you and give an early warning to any impending issue, thus allowing for an easy fix.
DO KEEP BATTERY PACKS IN A COOL PLACE FOR STORAGE
Batteries hate heat and having them in the hot car or trailer all the time will shorten their life. The same can be said for leaving them in a place where they can freeze. Store the packs in a controlled environment that has a cool dry place. I like to keep them in a small refrigerator set to the lowest setting so they stay cool without freezing.
Follow these 10 tips and you’ll increase the life expectancy of your battery packs and your investment. By charging correctly, your packs will always stay fresh and perform like new. This is something we all want out of our equipment, because this allows us to fly longer and more often-what’s not to like there? Enjoy!
Add this to the list: Get an battery voltage checker and check the battery before and after each flight. The checkers don’t cost much and this process will help you learn the discharge characteristics of the battery/plane combo, and will insure you start with a full, or at least known charge each flight.
Good tips! Thanks for sharing your experience.
Define “storage charge” please. Can’t give my packs a storage charge if I don’t know what it is.
most lipo chargers have a selection of charge mode ballance, fast & storage. Set to storage and your cgarger will do the rest. Proper storage voltage for a LiPo is 3.85V per cell.
Question, how do you do a “storage charge”?
All packs have a voltage listed on the face of them, so for a 2 cell lipo battery you will see 7.4 as the voltage.. That is the nominal voltage or “storage” voltage you want to charge to. A fully charged pack will actually be above the voltage it is said to have.
To be simplified for a123 😉
All Good advise!
How do you achieve a storage charge?
All the LiPo chargers I’ve seen for sale within the last five to ten years have a storage charge program to select, (along with a balanced charge, fast charge, discharge, etc.).
Charging outdoors is the safest option.
How much of a charge is considered to be a storage charge?
You don,t say how LOW to store a lipo battery. Is it 40%–30%- 20% ????
How can I determine the storage charge?
For John Left – typical storage charge is 3.8V per cell.
sorry, that should be John Lett, not left!
As someone who deals with automotive Li batteries since their infancy, I too cannot stress enough the importance of the author’s tips. Also be mindful of the other Li batteries being sold for general houshold use that dont carry these warnings, nor tell you they are giving you a litium pack. My daughter bought a cheap phone recharger pack that is not clearly marked as Lithium and there is no battery managment system (BMS) with it. I Heavily suggest going to your nearest granit counter supplier and get some scraps to construct a simple stone trough and attach a $20 smoke detector to a bracket immediately to the offset side of it (dont put it directly over it as the ensueing flames will shut it off prematurely).
6 of 10 actually pertain to “extending battery life”, unless you count “charging safely so your other batteries don’t catch fire” as extending their life. 🙂 And isn’t “Charge at 1C” and “Don’t charge at more than 1C” the same thing??
How do you determine your battery’s minimum voltage rating?
It’s 3.0 Volts per cell or 9.0 Volts for a three cell (3S) LiPo, though it is not recommended to ever do this since your battery may become degraded at this voltage and permanently damaged if you go below it.
Great info. Thank you!
One more question: how many cycles should a well kept lipo pack do on its lifetime?
I guess NOBODY knows what a STORAGE charge is ??
Jeb answered above but it’s usually about 3.85v. Most modern chargers have a storage charge feature. Connect the battery and set the charger for storage charge. This assumes that you have used your batteries of course:). I think it turns out to be about 40% when at storage charge.
General guideline is don’t run them below 3.7v per cell or below 20%. Tom made mention about using a battery checker. This is the best thing. I prefer the Hyperion one. Gives you %’s and all the info you need.
Jen mentions above that it is usually 3.8 volts per cell.
Most modern computerized chargers have a LiPo Storage function that will discharge the battery to a voltage level around 3.8 – 3.9v volts, which is considered to be the “Storage Charge” voltage.
My tip: don’t use a Triton 2 EQ charger. They don’t have the “storage charge” feature. I have one; it’s extremely over-priced and lacks basic features of a modern LiPo/LiFe/Li-Ion charger. Pretty lousy if you ask me.
i agree with all comment’. but i don’t see anything about getting disposing of them, i am just getting into electric planes. give some ideas so i don’t have to worry about them.
Be careful taking the battery out of your electric plane by pulling or using the battery leads or balance leads because after awhile they will come unconnected… you can solder them back on to the battery… but it’s a pain in the butt.
Not leaving batteries at full charge over night is also important! I fly from small 3s setups up to 12s 8000 setups and by charging the morning of and not the night before makes a huge difference in the life of the packs! I am just retiring some 6s 5800’s and they lasted about 3 years and were heavily used! The key is not to let them sit at full capacity for any long length of time, if I don’t fly a pack I immediately do a storage charge! I also charge at 1c, never take them below 3.7 per cell and never pull more amps than the packs can handle based on their C rating with 10-20% headroom. Ie: 25c 5000 mah can handle 100amps so max with headroom would be 80amps!
Take it easy on the exclamation marks, you’re gonna give yourself a heart attack.
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