Took the new (to me) Mavic Mini out this evening for the second flying session. The first had had to be curtailed after about 30 minutes flying because of a low RC battery, despite my having charged the RC fully beforehand. Today, the RC had been on charge for over 24 hours continously and was showing 4 leds.
I made certain that I inserted the smartphone cable into the micro usb properly (it was a little loose last time), and took off. The drone behaved immaculately, but I had a ‘Low RC Battery, Land Immediately’ warning after about 5 minutes, and hit the RTH. The drone was about 50m away and the RC was more or less drained when it landed.
I tried again about 20 minutes later, as the RC had recovered to 3 leds, and kept low and close. The warning came up after about two minutes this time. The manual says the RC has a run time of 4.5 hours with an iPhone (I’m using an 11, which is working perfectly).
I’ve got a problem, either:-
.I’m not charging the RC properly. I’m using the charger that came as part of the ‘Fly More’ combo from MPB, with the usb-micro usb cable supplied.
.The RC micro-usb socket looks a bit out of shape and may not be connecting properly. It will only go in one way, so I know I’m not putting it in wrong.
.The RC battery is fucked.
.The RC is fucked.
.Any combination of the above
Any suggestions?
I’m going to do some hovering tests indoors at home, which will annoy the tits off The Squeeze, and will try a different phone (though I can’t see why that would make a difference). If I can’t sort it out it’ll have to go back to MPB for a refund. I’ve lost a bit of faith in their product testing…
Just reading on a DJI forum, some say if your phone has very little charge in it ( usually android tho ) it will drain the rc very quick, maybe worth trying it with a fully charged phone apple or android ( with the rc fully charged ) & go from there if you haven’t already would be my first go to …
The remote only actually charges the phone battery if the phone’s battery has less charge than the remote. Both are at about 3.7v.
The power required to power the serial port is very small, but Djl has allowed the drain to be larger as indicated in the specs. That is very rarely needed. The deal is that not much power drains from the remote in normal use. But if the phone is dying due to low battery, the remote can support it temporarily.
Ok, I’ll try that first. The iPhone 11 which I use as a flying drone works fine, and was 100% charged at the start of the session; it is now at 84%. The RC was not charging it during the session and I turned it off when the session was over, but a loss of 16% for a total of less than 15minutes use seems heavy. OTOH the phone is transmitting to the drone, which must represent a significant drain.
First thing to do, tomorrow now, will be to charge the iPhone 11 and the RC both as fully as I can manage, and hover in the bedroom until the RC battery drains and the drone lands, noting the time the RC drains and how much %age phone battery is used. Next thing will be to repeat the experiment with my other iPhone, a 15, which seems to be be pretty robust as regards battery.
This will possibly not tell me anything, but will prove that the problem is with the RC and not the phones. I will now put the RC on charge overnight and keep my fingers, legs, eyes, testicles, and anything else I can think of crossed.
The drone batteries seem to be in good condition, which suggests that the previous owner looked after them, but this is of course by no means a given and he/she may well not have been as careful with the RC. It does state in the manual that the RC can charge a phone, but the green charging icon did not show on the phone screen, presumably because the phone was more charged than the RC.
The 2-way hub can also charge a phone, and the RC. I think the RC is fully charging but is unable to hold the charge, meaning it is discharging somewhere despite the current not being used for anything.
Another useful test is just to fly the drone at low height, within close visual range, and without a phone connected to the RC.
You will not have any views from the drone camera normally provided by the phone.
This will eliminate the possibility that the RC is draining via the usb socket, whilst transmitting to the active drone and maximising signal output (which is where you want your power to be going).
You could just leave the drone and RC powered and connected on a table, but this is likely to overheat the drone.
Testing indoors, and the RC wouldn’t hold charge (after being charged overnight) long enough to establish much except that it seems most probable that the RC is fucked. Fucked is a precise engineering term, ‘knackered’ means it might just get you home, ‘buggered’ means it needs a complete overhaul before it will run again, and ‘fucked’ means it’s fucked.
Switching the RC on, I’m getting the 4 leds on the first press of the button, then 3 leds and the little noise on the second press. This goes down to two leds within a few seconds, and off with the little noise after two more seconds. It will recover enough after a few minutes to repeat this performance, but will not stay ‘lit’ beyond that. It does not last long enough now to intitiate Go Fly on the phone, and has therefore deteriorated since yesterday. It behaves the same way irrespective of whether the phone is connected or not.
One of the early RCs has 2 usb ports - one on the left-hand side, and one between the grips.
You can only charge the RC using the micro-usb socket on the left-hand side, and despite the casing of the RC looking like the usb connector can go in either way up, it should only fit one-way round. There is scope for the port to have accidentally been damaged in the past. I suspect that your RC is not actually getting a good charge - but I could be wrong!
My RC only has the one port, on the side. I think you may well be onto something with your damaged port theory; it’s an odd peice of design to say the least, especially from a company that are normally pretty reliably on top of this sort of thing, and the outer shielding (which I think is the earth connection) looks a bit misshapen. As you say, the plug can only be inserted in one orientation, with the symbol on the casing to the front, but a user not fully aware of this could easily have attempted to force it in backwards and caused damage.
With nothing to lose by trying, I forced the sheilding back straight and attempted to charge it one last time; no dice! This suggests that even if the socket is not as it should be, there is something else wrong with the RC and it clearly has to go back. The charger that came with the combo charges batteries in the 2-way charging hub and in the drone without any problem, so I doubt that there is any issue with the chargeer, the cables, the hub, the batteries, or the drone, which leaves the RC. I think that the rechargable bettery in the RC is at fault, and appears to take the charge, but discharges almost immediately afterwards. The combo is unusable in this condition.
PMB replied promptly enough yesterday, asking for more information, so things are in hand.
