Options for charging DJI OSMO battery ?

[ovisopa]

I got an OSMO from a friend today while I made some videos for a client, it was very nice but the battery drained very fast, not even one hour

Did anyone dissasemble any battery, do you guys know if those are like the Inspire ones? "intelligent" and can be charged with normal charger at 12v ? I really need a portable charging solution for the OSMO as I also want to buy just the handle and use it with my Inspire X3 cam.

I measured the pins with a multimeter and the chargers outputs 12.56v on the exterior pins and nothing on the inside pins, I belive they are just for communication, but when I measured the battery I noticed that on there are 7.9v on either of the inside pins, this seems to be like normal lipo packs but not quite like the normal packs as the voltage doesn't drops to ~3.7v on the first pins pair, like in a normal lipo pack, on this one it's

• 7.9v on the first pair
• 7.9v on the second pair
• 12.5v on the third pair

If the battery itself handles the cell calibration than we can charge it with a normal 12v @ 1.2A charger, but if the charger needs to calibrate the cells than it's more complicated, as I think the used a standard 3S lipo wiring for the pins.

Any help or confirmation that can be charged with a normal charger is appreciated!

Thank you.

 

[FlyHighUSA]

I am not 100 percent sure but charging with a regular charger would in my opinion not be a good idea at all!!! DJI batteries are intelligent batteries and require a proper charger to get the best performance and life from it. The batteries are so inexpensive just buy 4 or 5 and you will be set for shooting all day. The life of the battery does need some improvement as like you said it doesn't last as long as say the Ronin M or other devices. I am looking for a better battery to be released at some point but who knows when. As far as making your Osmo charger portable, my solution is 2 fold, I use the A/C power supply in my Jeep Sahara Wrangler for power and it works just like at home and if that's not available I just use a power inverter and it seems to do very well, Hope this helps in some small way. I personally have not taken any Osmo batteries apart. Good luck with your Osmo

 

[ovisopa]

Well, they are called intelligent because if they are like Inspire's battery, the battery itself handles the cell balancing, not the charger, so the charger is not at all intelligent, just a basic 26v for the Inspire and 12v for the OSMO, but for the OSMO it confused me the presence of 7.9v on the other 2 pins. By looking at the original charger output voltage of 12.6v this doesn't looks to be intelligent charger, just a normal one, and the battery handles the cell balancing but I'm not 100% yet, I'll receive a new battery tomorrow and will give it to this friend of mine that gave me his OSMO, to test that battery with a normal 12.6v charger, I will tell him to use his battery in the original charger and mine battery in the standard 12v charger.

Any other opinions are welcome.

 

[FlyHighUSA]

Yes you are correct the are intelligent, thats exactly what I just said. I never said the charger is intelligent, I was only trying to help you. We are all learning together. Meant no disrespect to you.

 

[ovisopa]

All good

I just wanted to point out that in my opinion if the battery is intelligent than we don't need any special charger. I charger my inspire batteries when I'm away with a DC to DC boost converter to increase the 12v of my car to 26.3v

 

[FlyHighUSA]

Thats cool, I haven't tried that. I would like a faster better solution to the regular charger. Im just not sure how to safely do it. I have a Graupner charger and I bet it would do a nice job charging them. I may get the nerve to try it someday. Good luck, If you find a solution please let me know. Thanks .

 

[ovisopa]

I will certainly use a DC to DC converter for OSMO also, just to receive my own battery so I'm not busting my friend's battery in case something goes wrong

 

[FlyHighUSA]

I will certainly use a DC to DC converter for OSMO also, just to receive my own battery so I'm not busting my friend's battery in case something goes wrong

Great idea! Lol. He will appreciate that.

 

[ovisopa]

I made a holder for the OSMO battery and used a DC to DC convertor, the only issue is I didn't had one Step-Up converter , to increase from 5v power bank to 12.6v, but a step-down converter, I'll be using it for now from an old 4s lipo, the first tests are ok, I discharged the battery of the OSMO to 35% and than charged it with the DC convertor, you can see some photos with cells voltage before and after charging

 

[Kilrah]

Did you monitor the charging current at the start of the charging cycle?

 

[FlyHighUSA]

I made a holder for the OSMO battery and used a DC to DC convertor, the only issue is I didn't had one Step-Up converter , to increase from 5v power bank to 12.6v, but a step-down converter, I'll be using it for now from an old 4s lipo, the first tests are ok, I discharged the battery of the OSMO to 35% and than charged it with the DC convertor, you can see some photos with cells voltage before and after charging

View attachment 5700

Man I have to say great job. That's some true Frankenstein ingenuity. I would like to have one of those. When you start production let me know. I'm in. Great job.

 

[ovisopa]

Did you monitor the charging current at the start of the charging cycle?

I only monitored the input current in the DC to DC converter, and it didn't pass 1A, as the output current from it I couldn't monitor because I already soldered the pogo pins on the PCB and the PCB to the DC converter, I could maybe by cutting one trace of the pogo pins and place a multimeter on it.

My initial plan was to place an micro USB female connector on the input PCB, you can see 4 dots on the lower part of the picture, there should be the USB connector but when I realized that my DC converter wasn't a boost model, but a step down I didn't bother to place the traces as anyway I'll have to make another board.

View attachment 5703

I will try to find a DC converter with build-in LCD's and let you know how if the cells will still be balanced after 10 cycles.

FlyHighUSA, now I'm 100% convinced that the battery is indeed "inteligent" and it handles itself the balancing part.

 

[FlyHighUSA]

I only monitored the input current in the DC to DC converter, and it didn't pass 1A, as the output current from it I couldn't monitor because I already soldered the pogo pins on the PCB and the PCB to the DC converter, I could maybe by cutting one trace of the pogo pins and place a multimeter on it.

My initial plan was to place an micro USB female connector on the input PCB, you can see 4 dots on the lower part of the picture, there should be the USB connector but when I realized that my DC converter wasn't a boost model, but a step down I didn't bother to place the traces as anyway I'll have to make another board.

View attachment 5703

I will try to find a DC converter with build-in LCD's and let you know how if the cells will still be balanced after 10 cycles.

FlyHighUSA, now I'm 100% convinced that the battery is indeed "inteligent" and it handles itself the balancing part.

Agreed I'm on board

 

[Kilrah]

I only monitored the input current in the DC to DC converter, and it didn't pass 1A

1A on the input on 4s means about 1.4A to the battery, that's a bit much...

 

[ovisopa]

I will try to monitor the output also, I rotated the AMP potentiometer until the reading on the meter was about 0.92A but after a while I could see the maximum Amp was 1A.

The original charger is 12.6v @ 1.2A.

 

[ovisopa]

I discharged the OSMO battery again and made a time-lapse (WTF ... why the timelapse is 720p and not 4K ?? anyone tell me but I could'nt find any option for timelpase video resolution) with it while charging , offcorse the battery run out before the charging finished, it took about 1:09 minutes until the green led on the DC converter turned on

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So here are the voltages of the cells before and after charging

And here is the graph with the INPUT Amp used while charging, the curve looks similar on the output too but don;t know how much mAh ware used , the cells are not quite 4.2v, and the DJI Go app says the battery is 97% charged, next time I will let the battery even more in the charger, maybe it stills charging it slowly and the DC converter just turned the Blue led OFF / Greeen led ON as the current was very low, under 0.1A .. we will see exactly in the next charging cycles.




So far I'm very happy with this , I will try to find a DC Boost converter with build-in LCD and variable Current potentiometer as I have mine, 2 potentiometers, one for volts and one for current.

 

[FlyHighUSA]

From my understanding the time lapse will be in 720 not 4 k as set. I know mine did the same thing. I will investigate. Great progress on the charger.

 

[Mark harrison]

How about this:
Rapid Dual Charger USB OSMO Battery Charger for DJI OSMO Handheld 4K Gimbal