The combination of the drone and the LiPo battery provides longer flight times while significantly reducing the weight and flexibility of the drone. The LiPo’s battery characteristics and its chemical composition allow for greater capacity and higher discharge rates. This means that a LiPo battery pack in good condition, when properly maintained, can provide more “charm” to your drone and make it having longer flying time. So that’s why our batteries need maintenance.
Firstly, let’s see some following basic information of lithium battery for drones.
Structure of the Lithium Polymer Battery for Drone
Cathode: The active material is generally lithium cobaltate, lithium nickel cobalt manganate material.
Anode: The active material is graphite, or carbon with a near graphite structure.
Cathode tap：Use of aluminum (Al) material, made of a two-part composite of CPP adhesive and metal tape.
Anode tap：Use of nickel (Ni) material, or nickel-plated copper (Ni-Cu) material (good electrical conductivity), laminated from two parts, CPP adhesive and metal tape.
Electrolyte: a carbonate-based solvent with lithium hexafluorophosphate dissolved in it, or a gel electrolyte for polymers.
Separator: a specially molded polymer film, the film has a microporous structure that allows lithium ions to pass freely, while electrons cannot pass through, and the general thickness of the material is 12-20um.
Why to Keep Power Batteries in Good Condition？
The cathode material for lithium-ion batteries must have a location and diffusion path that can accept lithium ions. The cathode materials with better performance for current applications are transition metal oxides and lithium compounds with high insertion potential in a layered structure, such as LixCoO2, LixNiO2 and spinel structured LiMn2O4, etc. The insertion lithium potential of these cathode materials can reach more than 4V.
The negative electrode material is generally made of lithium-carbon interlayer compound LixC6, and its electrolyte is generally an organic solution with dissolved lithium salts LiPF6 and LiAsF6. A typical lithium-ion battery system consists of carbon negative electrode (coke, graphite), cathode lithium cobalt oxide (LixCoO2) and organic electrolyte.
Charge and discharge characteristics of lithium-ion batteries: As mentioned above, lithium-ion batteries have a nominal voltage of 3.7V and a full voltage of 4.2V, which are sensitive to overcharge and over-discharge. In order to minimize the vulnerability of lithium-ion batteries to overcharging, deep discharge and short circuit damage, the charging voltage of single lithium-ion batteries must be strictly limited.
Then, here are some tips. Please keep looking patiently.
How to Do?
Do Not Over Charge Lithium Polymer Batteries
Use a dedicated charger. This charger can be a Li-Ion or Li-Polymer dedicated charger, which are very close to each other. Some cell phone chargers can be used to charge lithium polymer batteries. This will not damage the battery.
Do not charge when left unattended. Use a safe location to place the battery and charger for charging. Generally no special instructions from the manufacturer, do not exceed 1C charging current.
Now, batteries support high current discharge also supports more than 1C current charging, but this will greatly shorten the life of the battery. So it’s more cost effective to buy 3 batteries and use them alternately than to buy one battery and have to fast charge it.
Do Not Over-Discharge Lithium Polymer Batteries
Low voltage over-discharge or self-discharge reactions can lead to the destruction of lithium ion active material decomposition, not necessarily reversible. And some serious damage to battery performance, or even explosion stem from any form of overcharge of lithium-ion batteries.
Do Not Store LiPo Batteries in Full Charge
A fully charged battery can not be kept fully charged for more than 3 days, if not discharged for more than a week, some batteries will bulge directly, some batteries may not bulge temporarily, but after several times of full charge storage, the battery may be directly scrapped.
Therefore, the correct way is to charge the battery after receiving a flight mission. If there is no flight mission within 3 days after the battery is used, please charge the single cell voltage to 3.80~3.90V to save it.
In addition, after a good charge for various reasons did not fly, but also to discharge the battery to 3.80 ~ 3.90V within three days after full preservation. If the battery is not used within three months, the battery will be charged and discharged once and continue to save, which can extend the life of the battery.
Battery preservation should be placed in a cool environment storage. If it’s long-term storage of batteries, batteries need to be placed in a sealed bag or sealed discharge box, the recommended ambient temperature of 10 ~ 25 ° C, and dry, non-corrosive gases.
Do Not Damage the Packaging
The outer packaging of the battery is an important structure to prevent the battery from exploding and leaking liquid from catching fire. A break in the aluminum plastic film of the lithium-poly battery will directly cause the battery to catch fire or explode.
Batteries should be carried lightly and tied tightly when fixing batteries in the aircraft. Because there is a possibility that when you do a big dynamic flight or fall, the battery will be thrown out because the tie is not tight, which is also easy to cause the battery skin broken.
This often happens during battery soldering wire maintenance and shipping. A short circuit can directly lead to battery fire or fire and explosion. When the battery is found to have a broken wire after a period of use and needs to be re-soldered, special attention should be paid to the soldering iron not to contact the positive and negative terminals of the battery at the same time.
What’s more, in the process of transporting the battery, the best way is to give each battery is a separate self-sealing bag and placed in the explosion-proof box, in order to prevent the transportation process due to bumps and collisions caused by a piece of the positive and negative electrodes of the battery at the same time encounter other conductive substances and cause a short circuit.
No Low Temperature
This is a principle which will be normally ignored by many flyers. At high altitudes there is often low temperature weather, when the battery is placed outside for a long time, its discharge performance will be greatly reduced, if you have to fly at room temperature when the flight time, it will certainly be a problem.
At this time, the alarm voltage should be increased (such as a single alarm voltage to 3.8V), because the voltage drop in the low-temperature environment will be very fast, the alarm immediately landed as soon as it rang. Then there is to do insulation treatment to the battery, before takeoff the battery should be kept in a warm environment, such as in the house, car, insulation box, etc.
To install the battery quickly when taking off and perform the flight task. To try to reduce the time to half of the room temperature condition when flying in low temperature to ensure safe flight.
How to Perform Maintenance on Batteries for Drone?
First, the battery body, handle, wire and power plug should be checked regularly to check if the appearance is damaged, deformed, corroded, discolored or broken, and if the plug is too loose from the aircraft.
After the flight, the battery temperature is high, you need to wait until the flight battery temperature drops to below 40℃ before charging it (the best temperature range for charging the flight battery is 5℃ to 40℃). After the operation, it is recommended to charge the battery slowly.
Then, when it comes to summer, it is better not to charge the battery immediately after discharging from outdoor high temperature or retrieving it under high temperature, and wait for the surface temperature of the battery to drop before charging it, which can greatly improve the life cycle of the battery. Summer temperature is relatively high, so the battery is best not exposed to the sun.
Last, in winter, after discharge the battery to take effective insulation measures (such as the use of insulation box preservation) to ensure that the battery temperature is maintained at 5 ℃ or more, low temperature environment battery life will be significantly shortened. When a low battery alarm sounds, you need to immediately return to landing.
So, i think now you might have the answer of “how to take care of your batteries for drone”.