Whats Really inside your Mavic Battery

[Dragonfly]

Ever wonderd whats inside your Mavic Battery and why its so expensive, well here are some inside pics ive taken of one just so you can see the 3 cells connected to the Ballance Board and the smart charge Board and circuit chips on top that take care of everything from charging to discharge to number of cycles and health state of each cell.

 

[Z953]

Do you think that you can replace the cells?

 

[Dragonfly]

This pack has one dead cell and being litium ion polymer may be hard to get exact same cell.

 

[Z953]

I know just about nothing about battery cells but this site looks like they have a LARGE selection of cells.

http://www.genstattu .com/

 

[GerdS]

What you can clearly see here, this batteries cannot get assembled automatically by robots or special machines, this is still done by hand, what has direct influence on the price. Would be interesting to know how many minutes a trained worker will need for assembling one.

 

[user888]

Also, don't try to replace only one cell as that one will have a different charge cycle count.

 

[Ping^Spike]

That's one hell of a logic board, for a battery

Thanks for sharing

 

[Reed]

It would be very interesting to know which chips are assembled there. Do they have Ram, Rom, Cpu? Is the Firmware update also reflected on this board?

 

[Ping^Spike]

That's one **** of a logic board, for a battery

Wait... even the word hel is censored here?! Lol

 

[bonzo]

hell no?... wow.

kinda reminds me of dji go.

 

[Dragonfly]

It would be very interesting to know which chips are assembled there. Do they have Ram, Rom, Cpu? Is the Firmware update also reflected on this board?

It does contain a Rom chip as the battery has its own firmware and you can and do upgrade this firmware for the battery. It is also the complete smart charge circuit and monitor for each cell as well as calculations for power usage and remaing power for duration of flight. Also for maintenance and discharging afterso many days to protect battery.
You can even see the large discharge resisitors on the bottom left.

 

[allenface]

Ever wonderd whats inside your Mavic Battery and why its so expensive, well here are some inside pics ive taken of one just so you can see the 3 cells connected to the Ballance Board and the smart charge Board and circuit chips on top that take care of everything from charging to discharge to number of cycles and health state of each cell.

Well there you have it. I took the end off my bogus dead but new battery and low and behold, they are basically gel paks, not the AA's or AAA's I had asserted several posts ago. I didn't go as deep as DragonFly did but replacing a gel pak may not be the smartest thing. These guys resemble old cell phone batteries that were encased in a plastic covering. At least I and we know what's inside these suckers. Is this disassemble battery a DJI OEM or a 3rd party? Betting the DJI and 3rd party batts look the same and are probably the same brand cell. I got two bad bathes I reckon.
BTW...reached out to the company but radio silence so I will stick with original statement of staying away from 3rd part batteries, especially ones from Powerextra.

 

[DanMan32]

Today's laptops and cellphones also use LiPos, what you called "gelpacks".
Many RCs do too. Ever notice what Symas use?
Reason being that they use up space efficiently and also less weight without the metal can. Downside is they expand with any release of gas from the chemistry while a can type will contain a moderate amount without expanding.

 

[WithTheBirds]

It would be very interesting to know which chips are assembled there. Do they have Ram, Rom, Cpu? Is the Firmware update also reflected on this board?

Yes to all. From memory the brains is a member of the Texas Instruments BQ30Z55 SOC battery management SOC family.

 

[WithTheBirds]

Today's laptops and cellphones also use LiPos, what you called "gelpacks".
Many RCs do too. Ever notice what Symas use?
Reason being that they use up space efficiently and also less weight without the metal can. Downside is they expand with any release of gas from the chemistry while a can type will contain a moderate amount without expanding.

The can types vent- a highly preferable scenario to exploding. There is no evidence that pouch cells have a safety disadvantage .The outcome from thermal runaway is substantially similar- rapid release of flammable gases.

 

[DanMan32]

I didn't say lipos have a safety disadvantage, just that they are more prone to showing swelling due to trapped gasses. Whether a moderate swelling is a danger when no electrical performance change has occurred is up for debate.
If can type li-ions are allowed to vent, seems strange they don't allow it with lipos.

 

[Flake7811]

Well there you have it. I took the end off my bogus dead but new battery and low and behold, they are basically gel paks, not the AA's or AAA's I had asserted several posts ago. I didn't go as deep as DragonFly did but replacing a gel pak may not be the smartest thing. These guys resemble old cell phone batteries that were encased in a plastic covering. At least I and we know what's inside these suckers. Is this disassemble battery a DJI OEM or a 3rd party? Betting the DJI and 3rd party batts look the same and are probably the same brand cell. I got two bad bathes I reckon.
BTW...reached out to the company but radio silence so I will stick with original statement of staying away from 3rd part batteries, View attachment 87895especially ones from Powerextra.

I bought a Mavic with that exact 3rd part battery and one original. I have to say that they are exactly the same in my opinion. The only difference expect the different lighting system and design in the front, that I can make out, it the clicking sound. You have almost certainly just been unlucky and got two bad batches.

 

[AnzacJack]

I have bought many 3rd party batteries for my P3's and everyone of them have died over the years while the originals are still flying. I have had 3rd party batteries die in flight, on about 3 occasions before I realised the connection between 3rd party and failures. Lucky the P3 is a tank and can survive some big drops.
From this experience, I would never fly with a 3rd party battery in any of my other drones. Lesson learned before it cost me big $$

 

[DanMan32]

I have bought many 3rd party batteries for my P3's and everyone of them have died over the years while the originals are still flying. I have had 3rd party batteries die in flight, on about 3 occasions before I realised the connection between 3rd party and failures. Lucky the P3 is a tank and can survive some big drops.
From this experience, I would never fly with a 3rd party battery in any of my other drones. Lesson learned before it cost me big $$

But who's 3rd party battery? There had been garbage out there, but PowerExtra had been OK.

 

[AnzacJack]

I really can’t remember to be honest. Probably some knockoff. When I bought them back in the day I didn’t even know they were not DJI until I got them and the lights where a slightly different design