Battery mini 1 to mini 2?

[WithTheBirds]

It doesn't directly work that way. The ESC and corresponding circuitry will be controlling the voltage to the necessary level by boosting / DC conversion at the expense of current drain and efficiency. Both battery packs could easily be drained at very high currents at lower than nominal voltages to keep up with the motor demand, ie 7.4V can be converted to 8 or 9V to keep up with demand / ESC control.

Depending on how efficient the conversion is, one would consume more current than the other. In the overall scheme of things, weight does matter while the nominal energy stored difference looks negligible.

You missed the simple fact that the mini 2 battery has slightly more wh (lower mah with higher nominal voltage) and is lighter so longer flight time is guaranteed. There is no buck converter to increase voltage.

 

[martin63]

looks like an original battery but used. from what I gather they do not sell after-market MM batteries yet, they can't get around the BMS chipset yet. You can make your own board, but with some heavy limitations like no auto RTH etc. Mavic Mini : B0B DIY battery parts by aeropic

Do you know if BOB work in MM2? For use in MM you have to downgrade firmware.

 

[scro]

@lee82gx How ESCs work doesn't affect the amount of energy (Wh or joules) contained within a battery. The point of my post was to highlight that comparing mAh figures for batteries of different nominal voltages gives a misleading picture of the battery's energy storage capacity (see post #18).

ESCs don't dictate the voltage the battery supplies to them, the battery chemistry and physical construction does.

 

[lee82gx]

@lee82gx How ESCs work doesn't affect the amount of energy (Wh or joules) contained within a battery. The point of my post was to highlight that comparing mAh figures for batteries of different nominal voltages gives a misleading picture of the battery's energy storage capacity (see post #18).

ESCs don't dictate the voltage the battery supplies to them, the battery chemistry and physical construction does.

I hAve indeed misread your post. It is likely true that higher "mah" capacity with the mm1 will not end up keeping the mm2 in air longer. Energy storage is almost equal in WHr, as well as being higher voltage usually is a better option than lower voltage discharge curve as the aircraft will suffer less conversion loss due to efficiency. I'm almost certain that there is some form of DC conversion in the mini if not, it will gradually slow down with the battery discharge curve. This does not occur, right?

 

[WithTheBirds]

I hAve indeed misread your post. It is likely true that higher "mah" capacity with the mm1 will not end up keeping the mm2 in air longer. Energy storage is almost equal in WHr, as well as being higher voltage usually is a better option than lower voltage discharge curve as the aircraft will suffer less conversion loss due to efficiency. I'm almost certain that there is some form of DC conversion in the mini if not, it will gradually slow down with the battery discharge curve. This does not occur, right?

The motor speed is determined by line frequency, not voltage. The motor drive inverter FETs are connected directly to B+ with no boost converters or pre regulators being employed (or necessary).

The slight differences you seem concerned with in nominal voltage of HV LiPO vs LiION are irrelevant, particularly when you consider the discharge curves and especially the lower cut off performance close to depletion. All the HV liPO provides is a capacity advantage.

 

[scro]

Thanks for the clarification @WithTheBirds I was fairly sure BLDC motor speed was dictated by the drive frequency rather than voltage or current. Might I be right in thinking current determines torque?

 

[lee82gx]

The motor speed is determined by line frequency, not voltage. The motor drive inverter FETs are connected directly to B+ with no boost converters or pre regulators being employed (or necessary).

The slight differences you seem concerned with in nominal voltage of HV LiPO vs LiION are irrelevant, particularly when you consider the discharge curves and especially the lower cut off performance close to depletion. All the HV liPO provides is a capacity advantage.

Thanks for educating me. But it still nags my mind a bit if you say that the drive frequency completely independent of b+ voltage is enough to control speed. If scro below is right, at least at some point you won’t be able to supply enough current to torque it up to speed, right? I must say I’m almost zero in BLDC motors of course.

and also, why would the mini 2 be able to withstand more wind, if the voltage is not a factor? I mean somehow mini 1 can’t drive at higher pwm frequency?

edit-ok, I am going to learn up more, YouTube seems to be a great teacher. Thanks.

 

[scro]

Thanks for educating me. But it still nags my mind a bit if you say that the drive frequency completely independent of b+ voltage is enough to control speed. If scro below is right, at least at some point you won’t be able to supply enough current to torque it up to speed, right? I must say I’m almost zero in BLDC motors of course.

and also, why would the mini 2 be able to withstand more wind, if the voltage is not a factor? I mean somehow mini 1 can’t drive at higher pwm frequency?

edit-ok, I am going to learn up more, YouTube seems to be a great teacher. Thanks.

The big difference between the Mini1 and Mini2 is the maximum tilt the standard firmware allows. The mini1 is limited to 20deg in P mode and 30deg in S mode. The Mini2 increases this to 40deg in both modes. More tilt means more horizontal component of thrust, and hence better ability to push against wind. Other DJI drones typically have 35deg or 40deg maximum tilt so the Mini1 has one of the least aggressive max pitch settings of the range.

 

[lee82gx]

The big difference between the Mini1 and Mini2 is the maximum tilt the standard firmware allows. The mini1 is limited to 20deg in P mode and 30deg in S mode. The Mini2 increases this to 40deg in both modes. More tilt means more horizontal component of thrust, and hence better ability to push against wind. Other DJI drones typically have 35deg or 40deg maximum tilt so the Mini1 has one of the least aggressive max pitch settings of the range.

That does not completely explain it, I mean why would mini1 be unable to hold a higher pitch? We have discussed that the battery power is not the cause, don’t tell me firmware, because something like this can be rectified by programming.....?

 

[scro]

That does not completely explain it, I mean why would mini1 be unable to hold a higher pitch? We have discussed that the battery power is not the cause, don’t tell me firmware, because something like this can be rectified by programming.....?

The mini IS able to hold a higher pitch, as a result of programming. I know, because I have done exactly this and seen the results.

Mini Getting Mini 2 Features?

I seem to remember, but cannot find it now....that someone posted the Mini would be getting some or all of the Mini 2 features via a software or firmware upgrade. I believe they suggested within a couple weeks. Does anyone else remember this or have info? I'm not unhappy with my Mini, but...

mavicpilots.com

 

[lee82gx]

The mini IS able to hold a higher pitch, as a result of programming. I know, because I have done exactly this and seen the results.

Mini Getting Mini 2 Features?

I seem to remember, but cannot find it now....that someone posted the Mini would be getting some or all of the Mini 2 features via a software or firmware upgrade. I believe they suggested within a couple weeks. Does anyone else remember this or have info? I'm not unhappy with my Mini, but...

mavicpilots.com

So, this would mean that if the Mavic mini 2 propellers do not stay in shape, it will be still prone to uncommanded descent....

ive been debating about getting a mini 2 due to its size...I was thinking maybe DJI fixed that by providing more power or speed or even pitch. Sorry this is out of topic.

 

[scro]

So, this would mean that if the Mavic mini 2 propellers do not stay in shape, it will be still prone to uncommanded descent....

ive been debating about getting a mini 2 due to its size...I was thinking maybe DJI fixed that by providing more power or speed or even pitch. Sorry this is out of topic.

DJI mostly fixed the problem on the mini1 by putting some additional code into the firmware that detects the early signs of a potential uncommanded descent, ie one or more motors reaching their max speed regularly. This code caused a warning to flash up on the app advising you to change the deformed props, and "beeping" the relevant motor(s). Ignoring this warning will likely lead to an uncommanded descent sooner or later.

On the mini2 the props have been made much stiffer and hence much less likely to get permanently deformed due to storage. They also provide you with a prop holder/guard for storage that reduces the chances of the props getting bent out of shape. More power/speed wouldn't have solved the issue as it was related to props thst were no longer suitably shaped to provide adequate lift.

 

[DHAirbus]

Hi, baterry from mini 1 is compatibile with mini 2?
And bag from MA2 is this same as mini 2

Combo bags- Mini2 bag slightly smaller

 

[DHAirbus]

Hi, baterry from mini 1 is compatibile with mini 2?
And bag from MA2 is this same as mini 2

Mini2 Combo bag is slightly smaller (same style)

 

[MATUBA]

thinking about ordering dji mini2 body from ebay to test the battery on the mavic mini

 

[lookout]

Just looked on the website the radius and dimensions are the same but the weight is 0.4 grams heavier on the mini 2 model.

Apparently DJI had stated that the mini 1 version only good on that or the Japan version of the mini 2.
Hey it has something to do with the motors being different?

Well I guess I can get refund when it arrives but worried my shipping costs might be same as the cost of the prop guards...

The batteries on the jp mini 1 were lighter, so maybe it's just a weight function.

And continued into the mini 2. So why does just any mini 1 battery work in the jp mini 2? Something needs a little more explaining.

So there's not a problem with switcheroo between lipo and lion batteries, just that the square peg on the mini 2 battery won't fit in the mini 1 hole?

 

[karlblessing]

The batteries on the jp mini 1 were lighter, so maybe it's just a weight function.

And continued into the mini 2. So why does just any mini 1 battery work in the jp mini 2? Something needs a little more explaining.

So there's not a problem with switcheroo between lipo and lion batteries, just that the square peg on the mini 2 battery won't fit in the mini 1 hole?

The Japanese version of the mini was due to getting around the registration requirements of drones weighing 199g or more.

But June of 2022 Japan changed it to 100g, so the Japanese version of the mini is now a moot point.

The Japanese version had a battery that had a single cell, weighed less but could only fly for about 15 minutes at most.

 

[Elthree]

So why does just any mini 1 battery work in the jp mini 2? Something needs a little more explaining.

So there's not a problem with switcheroo between lipo and lion batteries, just that the square peg on the mini 2 battery won't fit in the mini 1 hole?

The physical "doesn't fit" is a big reason why it doesn't work, but that may be partly to protect you.

The cells in the Mini 1 battery are cylindrical and this obviously guided the design of the casing. The larger size and more rectangular shape of the Mini 2 battery would have enabled them to pack more power in with the LiPos.

The battery has a microcontroller in there for management, and the host "talks" to the battery (doesn't just "suck electrons"). The Mini 2 host obviously knows how to talk to the Mini 1 battery, but I expect the Mini 1 firmware assumed that all batteries were Mini 1 batteries, and could do "the wrong thing" with the LiPos.
But given the shape of the batteries, it's a moot point.

Mini 2 chargers can also handle Mini 1 batteries, which is convenient. I have 2x Mini2 batteries and 2 of the slightly-heavier Mini1 batteries in my Mini2 kit and mostly treat them the same (although the Mini1 batteries usually get used last).