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o-gs / dji-firmware-tools

Tools for handling firmwares of DJI products, with focus on quadcopters.
GNU General Public License v3.0
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Mini 3 batteries won't unlock. #407

Open and-sh opened 1 month ago

and-sh commented 1 month ago

Hi gangsters Can not unlock mini3 batteries. Two pieces. One original, one not original. Was something changed recently? dji dji1

and-sh commented 1 month ago

Besides Is there some logger and decoder for dji messages? I have all wires accessibly in my setup, so I can peek a little. m2p

KTM1551 commented 1 month ago

Besides Is there some logger and decoder for dji messages? I have all wires accessibly in my setup, so I can peek a little. m2p

Thats awesome! So youre running 2x18650/21700 Liion cells with the stock BMS or did you find one to use in its place? Does it still behave like a stock battery in the App and on the Drone for RTH and all that? Cool work! I love my Mini 3 Pro!!

How is the run time with this setup vs the stock battery?

and-sh commented 1 month ago

Thanks 2x 21700 6000mAh vapcell, total weight about 150g BMS from not original battery plus. It behave like stock battery. Drone weight was slightly reduced. With these batteries it is roughly the same as a standard drone with a plus battery. Flight time is not satisfactory, it is about 40 minutes to 3V per cell. Due to large sag I can use only about 4.6Ah from battery. And power capacity (Wh) is lower than with LiPo battery. Typical discharge curves [here](https://budgetlightforum.com/t/bench-test-results-vapcell-f60-12-5a-6000mah-21700/222498

Looking for alternative batteries.

vapcell6 )

mililanigal commented 1 week ago

Did you recently run a firmware update? I did, and the drone now detects the batteries as non DJI batteries. Also, I was planning on doing a custom battery like you with high discharge (25A) samsung cells -- around same capacity. But, I'm really surprised your flight time is still about the same as the flight plus battery, with almost half the battery capacity and even more weight. It makes me wonder if the advertised battery capacities are not accurate.

and-sh commented 1 week ago

Yep, dji began to actively fight with clients. Recently I downgrade firmware to .600. It seemed to me that video transmission works better on it. Battery plus seems to be very well balanced, you can win only if you use very good batteries. Molicel p50b is in my opinion, more promising. To resolder the BMS I drove it into Shutdown mode with the help of dji battery killer. Disolder plus terminal first, solder back last. To start bms short positive terminal with output. But I do nor recommend to modify drone if you've played with it enough, it's easier to sell it and get an prebuild drone with inav. If you want hi quality video use gopro and gimbal. HD fpv - Caddx has some good solutions. They have no problems switching to FCC. With avatar hd vrx you can use any monitor or hdmi headset. For Long range - use 1.3Ghz analog VTX and 433 tx like myflydream. Yoy can go up to 50+km this way. Very promissing project is openhdfpv. If they get popular, China will make inexpensive kits for them like FC for Betaflight. Progress does not stand still, with such an attitude towards clients, they will forget about DJI.

mililanigal commented 1 week ago

Much thanks for the response. I'm guessing you're on a Mini 3 Pro? I'm on the Mini 4 Pro, and I don't think anyone has a way to crack it. I unfortunately can't downgrade the firmware. So, you're right, it would be better off to sell it and build my own. I'm still a big fan of DJI's air system, and their microOLED goggles. They are release the standalone O4 air unit, so I might just get that and build my own.

One final thing, have you thought about running another dji battery in parallel with the internal battery? That is, solder another DJI battery to some connectors and connect them in parallel. That should work with identical batteries, and effectively double the capacity. You will have the second battery extend underneath the drone, but for you, since you cut out the bottom already, should be fine. You can just velcro it to the undercarriage. I'm thinking of doing something like that.