TAKING CARE OF DRONE BATTERIES - BEING MISSION READY
Hard-earned, must-have info for public safety adopting a drone program.
It stands to reason, if drones are unique…so are the batteries, and they certainly are! Drones, more specifically multirotor drones, demand massive amounts of burst power from battery sources that must also be light and small as possible for maximum flight time. To meet this demand, the industries long-held answer for flight batteries is lithium-polymer, a.k.a LiPo. In many cases, these LiPo batteries are capable of delivering car battery levels of amperage, but at a mere fraction of the size. As you might imagine, with such power comes danger and special methods for care.
The chief and general rule for almost all LiPo flight batteries is that they must be stored on a fifty-percent charge. This is especially true if the batteries will not be used longer than a few days. Not doing this, storing batteries on a full charge or very little charge will in fact result in irreversible damage to the batteries. Damage will become increasingly evident as the batteries will offer less flight time and produce visible swelling. Eventually, batteries that have been left on something than a fifty-percent charge will offer no useable flight time at all.
Obviously having to store drone batteries on a fifty-percent charge is not ideal for public safety missions, as we’re all taught from day-one to be ready at a moments notice. However, having your flight batteries crap-out in the middle of life saving mission is not ideal as well. Fortunately, there are excellent ways to meet both the technical and public safety needs. Here are the best practices:
Charge En Route
LiPo batteries left on a 50-percent charge can be stored for literally months when kept in climate controlled conditions. Then in a matter of 15 to 30 minutes depending upon the specific battery and charger, be brought to a full charge. Factoring these things in, an ideal and proven practice is to charge the batteries while en route using 12-volt rate drone battery chargers, or a power invertor with a true sine wave. Ideally, when arriving on scene at least one flight battery will be ready with a full charge. In the case that a battery is not fully charged, it is perfectly ok to still use it.
Special Note – Power Inverters used for charging flight batteries must provide a true-sine wave. The inexpensive inverters typically found at local hardware and discount stores do not have a true-sine wave and will damage chargers and batteries. True-sine wave inverters generally start in price from $200 to $300 and will fully replicate alternating-current (AC) found at home or in your office.
Another tactic for being ready at a moment’s notice and maintaining batteries, is to cycle batteries. This measure is ideal for officers that have a very active drone program as it does require extra day-to-day work, but the benefit is that you always have at least one battery full charged. After three days, the charged battery is discharged to the golden fifty-percent level and then a different battery is brought up to a full charge.
Have Enough Batteries
Whether your agency chooses to charge drone batteries en route and/or cycle batteries, it’s important to have enough batteries. Having one or two batteries might be ok if you’re a photographer, but performing public safety missions requires at least five flight batteries. Five flight batteries will give you the capability to perform a battery cycle program, and when deployed…keep the drone in the air almost perpetually.
Tag and Log Batteries
Along with keeping a maintenance log of your drone, you should do the same for your flight batteries. Each time a given battery is charged, discharged, stored, or discarded…it needs to be logged.
Each battery manufacturer will provide guidance on how long their batteries will last. As a general rule though, LiPo batteries can last up to 300 cycles if maintained properly.
Budget For New Batteries
Even though LiPo drone batteries are indeed rechargeable, they also need to be viewed as a consumable. Varying from manufacturer to manufacturer, drone batteries typically will last 200 to 300 charge cycles when maintained properly. So, depending on how much you use the batteries, they may need to be replaced annually.
Let Batteries Cool
Immediately after use, drone flight batteries will be hot and should not be charged. It’s recommended that after flight, batteries should be cooled for at least ten minutes prior to being re-charged.
Handle, Store and Charge With Care
When it comes to care of batteries, LiPo batteries differ little from other technologies. Just like any other battery, you should protect them from any kind of shock (g-force) and, physical contact with other batteries or metallic objects that may create a short. When in transit, it’s highly recommended to place LiPo’s in a hard-sided case and thankfully most drone cases have allowances for battery storage.
When the batteries are being charged, it’s highly recommended that the batteries are attended to. If for whatever reason the LiPo batteries must be charged in an un-attended fashion, they should be stored in fire bags and/or charged in an area free of combustible material.
If you’re planning a trip on a commercial air-line, please double check TSA regulations before flight. Generally speaking, TSA requires LiPo batteries to be hand-carried so that they remain pressurized during flight. Putting drone batteries in your check-in luggage is illegal, and simply not safe.
I hope these practices for drone battery care has helped to educate you immediately, and most important of all…I hope that it assists you in your mission. If you have additional questions, please feel free to email me directly or post a comment below (requires public safety login). Also, sound-off with any comments or suggestions for future topics.