Mavic 3T for always-powered-on operation?

[Disloyal Customer]

I'm considering getting the Mavic 3T for use on a 50 acre off grid property in Alaska. The goal is to make a permanent launch pad outside our cabin where the drone will sit inside a plexiglass enclosure that can be opened via WiFi, with the drone connected to power through the USB port using a magnetic cable like this one so that it keeps a full charge, receives satellites and is always ready to go. I'll have a cooling fan installed to keep the drone cool inside the enclosure. In the cabin we'll have the RC Pro Enterprise wall mounted on a bracket, plugged in and powered on, with an HDMI output to a large flat panel.

The goal is to, based on sensor alerts we get throughout the property, hit a button located next to the RC Pro to remotely open the enclosure over the launch pad, and then tap on an autonomous mission on the controller and quickly launch the drone on its way to do some surveillance for us (looking for bears, moose, wolves and such that may have triggered our sensors on the property).

Does this seem viable with this drone? Some specific questions I have:

1. Does anybody know if the drone motors will start, or the drone attempt to fly, if a USB power cable is connected to the drone and charging it? If the answer is no, would it start/fly if power was shut off to the cable while still attached to the drone? I'm hoping to rig it up with the magnetic cable to keep the cable out of the way of props coming up from the floor of the launch pad, so that when the drone launches it simply disconnects the magnetic cable.

2. While it seems iffy that the RC Pro Enterprise will run Litchi from what I've gathered (or at least at this point in time), my understanding is that I can create several waypoint missions and save them in the DJI Pilot 2 app and at least quickly send the drone to various pre-programmed spots with the cameras looking straight down. From what I understand, the drone doesn't support point of interest so I won't be able to have the drone focus on various points while flying a waypoint mission and will have to settle for a fixed gimbal setting like looking straight down. I haven't used waypoint missions in the DJI Pilot app, and have two specific questions about that app. A) would it allow setting a waypoint mission to start recording video upon launch, or is that something that has to be done manually? and B) would it allow me to pause the drone position during the waypoint mission and manually look around before hitting resume on the waypoint mission? From what I've seen I should be able to pause/resume using the remote pause button or the on screen pause button.

Many thanks in advance for anybody who can offer feedback before we fork over the 6K for this drone!

 

[Yorkshire_Pud]

Have you tested whether or not the drone will charge whilst switched on. With my minis you can not do both simultaneously.
Besides I would suspect that keeping a battery at full charge is probably detrimental to its rather expensive health.

 

[Disloyal Customer]

Have you tested whether or not the drone will charge whilst switched on. With my minis you can not do both simultaneously.
Besides I would suspect that keeping a battery at full charge is probably detrimental to its rather expensive health.

That's a great point. I don't have a drone that can be charged directly like that so I haven't tested it. But that's definitely something to find out for sure.

For battery health, I could have a controller running the power to the charger so that after X minutes it shuts off the power.

 

[Disloyal Customer]

I contacted a large online seller of DJI drones and asked them whether the drone will power on, and launch, while being charged through the USB-C port. They said it would. But they may have been just telling me anything in the hope of making a sale. The conversation wasn't super confidence inspiring.

 

[Yorkshire_Pud]

I contacted a large online seller of DJI drones and asked them whether the drone will power on, and launch, while being charged through the USB-C port. They said it would. But they may have been just telling me anything in the hope of making a sale. The conversation wasn't super confidence inspiring.

.......... I would wait for confirmation from an owner.

 

[Disloyal Customer]

.......... I would wait for confirmation from an owner.

Definitely will do that!

I used the DJI support chat and this was the result:

Hello, I am thinking of upgrading to the Mavic 3 Thermal drone. I have a question I need answered to see if it will fit my application. Will the M3T power on while being charged through its USB-C port? Thank you very much for any help!

Matt from DJI: "Yes, the drone could be powered on while you charging it"

That's excellent. Will it also launch flight while it is being powered through the USB-C port? I would use a magnetic cable so that the cable would disconnect from the drone automatically during flight launch.

Matt from DJI: "I'm afraid that will not be possible."

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Matt offered to elevate my question to an expert and says they will get back to me in a couple of days so perhaps I'll have some better info to share. But I will definitely wait for somebody with the machine to confirm for sure.

 

[Yorkshire_Pud]

Definitely will do that!

I used the DJI support chat and this was the result:

Hello, I am thinking of upgrading to the Mavic 3 Thermal drone. I have a question I need answered to see if it will fit my application. Will the M3T power on while being charged through its USB-C port? Thank you very much for any help!

Matt from DJI: "Yes, the drone could be powered on while you charging it"

That's excellent. Will it also launch flight while it is being powered through the USB-C port? I would use a magnetic cable so that the cable would disconnect from the drone automatically during flight launch.

Matt from DJI: "I'm afraid that will not be possible."

----------------

Matt offered to elevate my question to an expert and says they will get back to me in a couple of days so perhaps I'll have some better info to share. But I will definitely wait for somebody with the machine to confirm for sure.

let's just say I would still wait for confirmation from an owner lol

 

[Disloyal Customer]

Thank you for contacting DJI Technical Support.

We are grateful to assist you with your concern and really want to help further.

The drone can be turned on while charging.

As for the second question, because we don’t have this kind of magnetic charging cable officially, so I’m sorry that we haven’t tested the situation you mentioned, and our use is to fly without plugging in the cable. The flight of the plane needs to search for satellites, so the tests are all carried out outdoors, and the situation of taking off while plugging in and charging is not considered. Our official advice is not to use it in this way. It is recommended to fly with a full charge. In case the cable used is not disconnected during take-off, after all, it is a third-party product and we cannot guarantee the use effect, and there will be certain safety risks and hidden dangers.

Should you have any further questions or concerns, don't hesitate to contact us back.

Take care and stay safe!

Best regards,
Krystal
DJI Technical Support

 

[Ralph thompson]

Interesting idea which I expect folks that do search & rescue have thought about. However the batteries are not designed to be fully charged continuously. The recommendations are to discharge to 50% when not I use. Leaving the batteries fully charged can cause swelling & cracking.
Are you going to be living in the house? In which case setting up and launching the drone with the RC Pro only takes a minute & you can do a quick checklist to ensure it’s safe to fly. If yr not going to be in the property then how does the drone reconnect to power when it returns? Also RTH arrives at the home point and comes straight down. Home Point not accurate enough to have the drone fly back into a small cubicle.

 

[MavicAir2Marc]

IIRC there is someone that makes a security drone with that type of operation but I'm sure it's not cheap. If I can find where I saw it, I will post it here later.

 

[MavicAir2Marc]

Like I said, probably not cheap but it will do what you are asking...

 

[Disloyal Customer]

However the batteries are not designed to be fully charged continuously. The recommendations are to discharge to 50% when not I use. Leaving the batteries fully charged can cause swelling & cracking.
Are you going to be living in the house?

It's a good point about battery care. Six months ago I may have dismissed your point about battery health, but that was before we had an electric chainsaw lithium battery burst into flames in our cabin. Like a dummy, I had left the chainsaw outside and it got rained on. I put the battery on the window sill to dry off. The wife and I went up into the loft for bedtime and we saw a huge burst of light, I scrambled down the stairs immediately. From burst to me throwing the lithium onto the wood floor was no more than two seconds I estimate. We put the fire out quickly, but it still managed to crack the window. Had we not been in the cabin when this happened, we would have lost our cabin and much more given we're in a heavily forested area way off grid with no town or fire department.

We bought a container made to store lithium batteries after that and we keep our batteries in that when not in use. And if any have any cracks or swelling or don't operate normally, we dispose of them.

All considerations when it comes time (if it comes time) to make a launch pad enclosure for the drone outside. I'll have to try to figure out materials that will contain a fire without messing with the drone's navigation equipment.

As for the battery state of charge, I can have the charging power supplied through a microcontroller that turns power off and on so I can keep it from being power always on when not needed but I'll have to figure out how much power it uses perched without motors running over time and such.

We will be at the cabin but I'd like to make the process as easy and quick as possible. I'll check out that security company Marc recommended but I suspect he's right about the cost being prohibitive.

 

[Disloyal Customer]

One of the uses for the drone will be scanning trails for Brown Bears before we go on walks. Another will be spotting them on the property and perhaps using the loudspeaker to try to convince them to go elsewhere.

This one we've dubbed "Freddy" brought her large cubs with her a couple years ago and destroyed our yurt for us along with a nearby shed while we were away one weekend. One of the many mistakes I made since the five years or so we've been living off grid, was thinking when it was freezing outside the bears would be asleep. So the electric fence around the yurt, powered by solar and a lithium battery, would not be powered since the lithium doesn't take a charge below freezing. I figured the electric fence not being on wouldn't be a problem, but I was wrong. So we built a cabin with bears in mind and it's pretty fortified.

Freddy came back almost a year later exactly to check out the cabin. She tried to eat one of our cameras we had lodged inside a birdhouse on the deck.





Where we live, we have a ton of bears and moose (even more dangerous) and it's so heavily forested that we have encounters frequently. This moose came charging up in front of our cabin (our cabin is on a ten foot high deck, so this image is me looking down on him over the rail). He was in a huff probably chasing a cow and the image doesn't do it justice, he sounded like a tank running underneath me. We've only run into a bull once on the trail and he didn't see us and turned up ahead of us, but during rut they're terrifying.




Walking around with my wife, I'd like to have some good situational awareness and hopefully train the bears to stay off the property eventually. Just a few months ago walking on a trail a small black bear cub darted across a crossing path maybe thirty feet in front of me. Then mom came out standing up and grunting and agitated while she very clearly was sizing me up and deciding whether or not to charge. It's only a matter of time before our encounters get more exciting, so I am frequently flying the drone out trying to get a sense of the property before we walk to the garden and various places on the property. Anything I can do to make the process easier and more efficient is worth doing for me in the hope of preventing a more exciting or tragic story.

 

[Ralph thompson]

Envious, I'd love to be amongst all that nature. Living in urban Montreal, the best we get is occasional snowy owl, coyote or the neighbours pesky cat.

 

[Disloyal Customer]

Envious, I'd love to be amongst all that nature. Living in urban Montreal, the best we get is occasional snowy owl, coyote or the neighbours pesky cat.

It's a great way to live, but it has its drawbacks for sure. I wish we would have embarked on this life decades ago when we were younger. No running water, no grid, and for us the nearest dirt road is a mile and a half away and a thousand feet below us. It took us a few years to acquire a small undeveloped property on the dirt road so we have a place to park the truck. Then we made an ATV trail up to the homestead and we have to use a tracked vehicle from there because wheeled ATVs get stuck much of the time. So hauling stuff up to build is expensive, and we've done at least a half dozen helicopter sling loads to get building materials and other things up there.

Pros and cons.

The wife and I were just watching a documentary on snowy owls last night. Amazing creatures. Specialized microscopic feather endings that allow them to fly silently unlike other birds. Super stealth. I saw one from the yurt a few years ago in a tree on a moonlight night. I walked out on the small deck to take a better look and he flew right by my head and I never heard a thing.

We have lots of coyotes (and some wolves) here too. This is one from a couple weeks ago.



And here are a couple of lynx from two days ago hunting snowshoe hares more than likely.



We have generations of "tamed" squirrels now. They come by to get eats and let me pull ticks off of them every spring. I've probably removed more than a hundred ticks by now. They come inside the cabin and hang out on the couch, sit in our laps. Moms bring their babies up with them in the early spring. Cutest little Red Squirrels, but they're territorial and fight with each other constantly.



The nuthatches land on our fingers and fly into the cabin to get fed as well.



While we have tons of Canada jays, Stellar jays, and a few Magpies who come by regularly to get fed and eat out of our hands, we have not yet been able to convince Ravens or Crows to come by. Outside of this sweet Raven that I found on the trail and thought was having some issues flying. Turns out he had the Avian Flu which is a real problem here. The wife was gone so he stayed with me for about four days until he passed. It was sad. Amazing creature. Very intelligent. I gave him tons of food and water hoping he'd be able to pull through, but all he wanted to eat was blueberries and just a tiny bit of meat. Poor guy. He was perched out on the rail and I had the front glass doors open when it began to rain. I had made a series of logs so he had a way to get up and down from the perch to the cabin. Once it started raining he plopped down, log by log, and came into the cabin and went over to the wood stove to warm up. Really tore me up when he passed even after just a few days of interacting with him.

 

[mobilehomer]

I would check the hunting laws first. I know, you are not "hunting" for sport, but you are "hunting" just the same. Some states strictly forbid using drones for tracking ANY type of wild life.

 

[Disloyal Customer]

I would check the hunting laws first. I know, you are not "hunting" for sport, but you are "hunting" just the same. Some states strictly forbid using drones for tracking ANY type of wild life.

I don't think it's "hunting." No more than bird watching is hunting or nature videography is hunting. But you're right it's important to keep on top of the laws and Alaska is very serious about hunting laws. This wouldn't count as hunting though. You can even use a helicopter to track a wounded animal that you've already shot, I'm pretty sure. There was a court case not too long ago along those lines. But at any rate, we're not hunting with drones.

 

[MAvic_South_Oz]

snowy owls last night. Amazing creatures. Specialized microscopic feather endings that allow them to fly silently unlike other birds. Super stealth.

Wow, some drone manufacturer / military will lock onto this little gem, soon to be real stealth drone tech

Welcome to the forum too, and sounds like a perfect place to be located in this day and age.

 

[Disloyal Customer]

Thanks to a forum member for taking this through the paces. Turns out this solution won't work. This is what a pilot here told me:

OK, this is what I've found out. The M3T would not power on when plugged into the charging cable. It would simply be in battery charging mode. I proceeded to power the drone on without the power cable plugged in. After the aircraft booted up, I plugged the power cable in. It connected to GPS. However, the Pilot 2 app states "Aircraft connected to USB device", unable to take off". I let it run like this for several minutes. The battery % was going down with the drone powered on and the charging cable plugged in. It did not appear to be charging it at all or perhaps the power consumption was greater than the USB power input. I was a little disappointed with the results. I hope this helps.

 

[Horsefly]

The info provided above is correct. The battery will not charge and the AC will not take off with the USB in. It will "turn on" because that is how you download the info from the disk but the DJI rep implying that it will operate is very disingenuous.

For your application you might consider tethered flight. I searched and got several hits but have no first hand info so I won't recommend. Getting a launch from internet may be possible with these solutions.

Here is a list of docking stations, some of which have remote operations. 10 Best DJI-Compatible Drone Docking Stations To Consider for Autonomy

Large animals will show up for kilometers in the open on thermal but like most thermal you are really only good for about 3 or 4x zoom. Using the visible high zoom in daylight with thermal low zoom can find very small camouflaged animals that you would never find with visible only.