Keeping Batteries Ready to Go

[miturnbo]

I'm with a disaster response team and we are developing our drone program for rapid response. One thing we are finding is hard to manage is keeping the batteries charged up since it does tend to shorten the life of the battery to keep charging it to capacity. I'm wondering what other response agencies are doing to manage their batteries and keep them ready to go at a moment's notice.
We have an Inspire 1 and Phantom 4 and are looking to add an M200 at some point.

 

[TreeLineView]

I have multiple DJI products going back to Phantom 3. I have always left the default discharge time which is 10 or 14 days I think. Strict about rotating all my batteries. I top of all my batteries about every 21 days. May not be a best Practice but I have never had an issue with performance or longevity. Currently have about 30 batteries and counting

 

[miturnbo]

I have multiple DJI products going back to Phantom 3. I have always left the default discharge time which is 10 or 14 days I think. Strict about rotating all my batteries. I top of all my batteries about every 21 days. May not be a best Practice but I have never had an issue with performance or longevity. Currently have about 30 batteries and counting

Good to know. Someone along the line told our leadership that they should not keep the batteries topped off because it's bad for them. But it does present other problems.

 

[JustinR]

I am involved with the same type of work and I just look at it as an expense. You need the batteries ready to go. At the very least, maybe have half your batteries ready to go and have a car charger so that when you get the call, you charge on the trip out. I am probably going to go with two car chargers since they will charge two batteries faster than the charging dock made for four. It only charges one battery at a time and it seems to me like it takes longer on each batttery (might not actually be the case but it seems that way). I look at batteries as a disposable cost to using the drone. I currently use a mavic pro and have 5 total batteries. when operating, I can keep the drone in the sky pretty constant with five batteries.

 

[John Githens]

Good thread to see. I'm also looking at establishing a distributed, rapid-response capability that includes volunteers at homes across a large area, one of which might be able to reach a scene where visibility with a drone would be useful. Same concern about having batteries ready to go and use. At lowest overall cost over time. I have one small charger for a car/truck, however it does take time to increase the charge level on a battery(ies). I'm leaning toward advocating for using Parrot's Anafi for its light weight, ease of operation, and long flight duration. Lower cost batteries and chargers would help sell the project.

 

[IronManNDFW]

I belong to a couple different organizations who do SAR/DR/EM volunteer work. I am unsure if there is even a program in one of the orgs, and the other is attached to the STEM program, not being used for SAR work at this time.

I come from the Manned Fixed WIng Side of Aviation, and have been doing SAR work for 25 years, and been using the FEMA format for the past 10 years. I spent most of this year taking FEMA position Specific Courses while living in Florida. I got to meet a lot of the EOC managers, Trainers, FDEM personnel, Volunteers, USCG members, and EM personnel from across the state of Florida, and USCG District 7 IMT/SAR program. I have since relocated back to the Dallas the fist of November.

I have read all the docs on my new P4PV2. I charged 3/6 batteries, to see how long to charge, and then discharged them to 50% after 2 days. I have read that bringing them down to 20% is better.

@TreeLineView has what I have read to be the best rotation and program offered here.

LiPo batteries are different than any other..

For those interested NFPA 2400 is just released along with the FEMA UAS program. The FEMA UAS program has set courses to be completed before deployment. One issue that some may have a challenge on is the OSHA 29 CFR Pt.1910.120 HazMat awareness course. There is an optional FEMA Emergency Management Institute (EMI) online course to fill that requirement.

I would very much like to make contact with each of you here, and see how we can work together as a Unmanned Aircraft System Team - Type 1 for any disasters comes up where our skill set can be used.

Contact me at BobSides01@gmail.com or 214-998-1677.

 

[John Githens]

This website was slow to display your post. Did not see it until 9AM PT. See my email reply.

 

[BigAl07]

I'm currently working with our Incident Management Team (IMT) both locally (county) and on the state (NC) level. I also teach/train Emergency Services Depts on setting up and maintaining a sUAS program around the southeastern US. Below are some of our "Battery" procedures we use and teach to other agencies.

I've been "doing this" for many years and one thing I'm very particular about is our inventory of batteries. I currently have approx72 High Capacity (more than 2200Mah) LiPo in our inventory and probably that many and more again in mini (less than 500Mah) batteries we manage. Our inventory includes SMART batteries (DJI brand) as well as "NonSmart" batteries. I'll admit we treat our lower/min capacity packs with my less care and concern. They are for our "fun" aircraft and non-mission critical applications.

Smart batteries are all set to start (this is important to note that the START of the discharge and time of completing the discharge is a few days apart) AutoDischarge at 5 days. If we aren't using a battery the next day (usually we are) we leave it be and let it auto-discharge to "Storage Level".

Our Non-Smart Batteries we treat just like the SMART ones noted above except we manually discharge them to storage level either via flying (preferred method of course) or manually using a SMART Charger that allows us to discharge (just one touch of a button) to 50%. Most of these take about 3 hours to go from 100% to 50%.

We routinely go through each and every battery 1x a month and note charge/discharge cycles, battery health, and determine whether or not it's time to do a DEEP discharge cycle. (this is old school method so YMMV). This monthly inspection is part of our P&P's and noted/logged. This also allows us to "See" a pattern in a battery hopefully before we have a failure.

If we know we are going to fly the next day we top off all packs and Tx to 100% the night before or the morning of the flight session. Otherwise all batteries except the Flight READY set are at storage level and kept in a slightly cooler area.

Also we always have at least 1 flight of batteries (between 1 and 6 batteries depending on the aircraft) Flight READY 24/7 for any given aircraft sitting at 100% charge so we are always 100% mission ready. We also have multiple charges and the ability to charge en route and on scene so a single flight of batteries has proven sufficient to date.

If you decide to go this route you'll need to take very clear and detailed battery maintenance notes so you're not leaving the same flight packs at 100% over and over. LIPO do not appreciate being kept at 100% for extended periods of time over and over. You'll fool around and have a PUFFED pack which is useless and an accident waiting for a place to happen.

 

[Dave Pitman]

My $.02

The data suggests that a lithium polymer battery sitting fully charged or depleted for any length of time is the worst thing for them.

I pretty much agree with @BigAl07 's proven approach. With the exception of a couple of things.

We are not "on call" so we don't keep any batteries fully charged at all times. We do have some connected to a wi-fi controlled switch and we can turn the charger on at any time from anywhere. We also have in vehicle charging so we can finish or charge more enroute.

We only use the auto discharge feature as a backup. If batteries are charged and not going to be used within 24 hours, we manually discharge them to storage level.

We very rarely use the "deep discharge" strategy initially proposed by DJI. The practice is detrimental to the lipo itself and it is actually to re-calibrate the chip monitoring the state of charge. The latter is important though and we always compare the stated capacity with the capacity showing for the battery in the app. If it is greater than a 5 % difference, or if cell values are unreasonably unbalanced, then we discharge and recharge to normal levels in a controlled environment until the #s are good. The deep discharge to reset the chip is a last resort for us. DJI has lately not advocated using the Deep Discharge strategy on a regular basis like they used to. It is now more of a last resort for a pack that is having issues.

We don't consider our lipos "disposable", however we won't operate with one that shows signs of issues either. As Al said, it's good to keep a record to hopefully get a heads up that something is going down hill before it is the cause of a problem.