Welcome Inspire Pilots!
Join our free DJI Inspire community today!
Sign up

Inspire 1 battery mod: never ending crusade ...

Joined
Jan 16, 2021
Messages
178
Reaction score
77
Age
51
Actually it was a lack of confidence by DJI in the TI chipset. Nothing more.

I have something of an "inside line" on things from an engineering perspective and I can tell you all this, that DJI will aggressively defend it's intellectual property and prevent others from producing Inspire 1 replacement batteries. There are details I will not go into detail here, but lets just say it is a legal issue for them as well.

They have no choice, but there will NEVER be a third party DJI battery for the Inspire 1. Even if you reverse engineer the command set for the comms between the aircraft and battery, to produce a commercial product using that communication will end up in a lawsuit. DJI has always been adamant about protecting their IP and that protocol is still used in many other drones they produce.

Now, back to the chipset, I can 100% confirm I can reprogram the BMS chipset to use a "NEW" battery pack, and I can confirm that unless you do it properly you run into what dobmatt has and that is reduced capacity and longevity. You need to "recalibrate" the BMS to the new pack. Due to the way DJI has implemented the TI chipset it is not a matter of just putting the chipset in calibration mode. I have spent many many many hours working on this, including using larger battery packs and even though it may seem somewhat selfish to keep some of this information to myself, it is because I have spent a lot of time/money/energy working out these details and coming up with solutions. I originally went into this looking to do it for commercial reasons (see a need, fill a need and make a profit), and in doing so have a lot more invested in this than most. Now that doesn't mean I won't EVER share what I know, but I need to make sure that the information I have isn't subverted and used to "pump peoples egos" which seems to be the modus-operandi for those that wants hits on youtube to make money for themselves, as well as making sure people don't half-hack a "TRUE" solution in place and lead a whole lot of others down the wrong path. There is also the very REAL probability that people would use this information to reset cycle counts and dates/timers and sell people "like-new" batteries that are total garbage. Sorry, just look at the scheming and scamming goin on with eBay in regards to these batteries. I can tell you, if I was unscrupulous I could EASILY make a battery that will last only 5 minutes look and report like a new 20 minute TB48. After 3-5 cycles it would only report 1400mAh, but that is after the fact.

The few things I can verify is:

1) I can totally reset a battery (TB47/TB48) to "as shipped" calibrated status. This is used to repack a battery with new cells. You must recalibrate and re-age the BMS. This is where almost everyone else messes up and why the Swiss guys that rebuild the DJI batteries state that they don't change the cycle count is because there is a LOT that goes into redoing things. It is NOT a matter of just "zeroing it all out". There are counters, timers and everything else that once they are started you WILL mess it all up by just setting them to zero. There is a "fused" set of counters that once started cannot be reset back to "factory" mode. Doing so messes up ALL of the calibration stuff and you will see a VERY quick reduction of capacity, along the lines of what dobmatt was seeing.

2) I can also redo the capacity, cycling and charging parameters, including the cycle count. This allows me to change the capacity, the charge/discharge rates, even the bias used to balance the cells. I have built a 9000mAh battery as well as a 11400mAh battery and had them both work just fine, for reference. Packaging is a nightmare. I will say the "best" solution I have seen so far is the previously mentioned 12000mAh battery that was offered for a while. The big concern there is that the cell used are not LipoHV cells and are not rated for the continuous use the original DJI cells were.

3) All of the errors that display as far as cell status are NOT power fail modes set via the TI chipset. They are translated via the CPU. Now, that does not mean that DJI didn't just map a status bit in the TI tables to represent the failure modes, I am still doing some mapping to compare a set of failed batteries vs a non-failed battery to verify, it is just that I have not had a lot of time to finish that work.

4) DJI does use very high-quality cells. Most Lipo suppliers have a hard time producing these cells. I can also verify that almost ALL Lipo producers in China will state that DJI owns the exact specs for their cells and they CANNOT produce exact cells as a result. Now, I also know that the Swiss company shopped the Lipo manufacturers and convinced "someone" to produce them "like" cells for their rebuilds, so it CAN be done. I wouldn't want to hazard a guess at the quantities they had to commit to so they could secure that production. I also HIGHLY question the quality and viability of that rebuilt product for long-term use, since I have first hand experience with 3 different Lipo producers and they ALL have huge issues producing consistent quality. And that includes one producer that couldn't produce proper cells for that Swiss company either (since they couldn't produce for me as well). So unless they found some magical producer that can get near 98-100% viable product out, I would have to imagine there is only about a 80-85% useable product coming in (which is generous form what I have experienced), which is a logistical nightmare to deal with the bad product. Now this is with totally "built" packs that are pre-soldered, but anything less (such as individual cells and PCBs) is a rebuilders nightmare unless you are charging 2x what DJI was charging for them, which they are not. Point being that getting matched, rated, scaled and calibrated 12-cell "packs" is a MASSIVE endeavor. DJI produces just that and they STILL had failed product at times. I have on hand 7 "built" packs and only 4 are viable and out of those 4 only 3 are matched and only 2 came calibrated (which means they were flukes, not intentional builds), so I know what I am talking about first-hand.

Lastly, I can verify I have, on hand, 4 *NEW* TB48 batteries. I won't explain what/where and how I got them, but I might just share this source at some point here. All of these batteries have production dates of the cell packs of 10/2020 thru 11/2020 and serialized dates of the complete battery of 12/2020 for all. I will also state that I did not pay over $400 for any of them either. I won't state how much I paid, nor the sourcing (for now). Again, this is because I am more concerned of the source changing and limiting the availability and I know too many people "in the profession" that rely on these for "paying work" that are redoing their stocks as I type this that I would prefer to "get what they need" before I go public with this information.

As it stands, my personal stock includes 10 TB48 batteries, 4 brand new, another 4 with less than 20 cycles and the remaining 2 with less than 30 cycles. All are either 100% capacity or at or above 91% capacity (most are 94-97%), so I "personally" am set. I can verify that I flew for over 24 minutes with one of the new TB48 batteries and it NEVER did a serious voltage drop on hard acceleration the way the oldest batteries (TB47 with more than 74% capacity) of mine do.

Sorry to be so cryptic and evasive, but I would hope I explained exactly why I am doing such for now.
 
Joined
May 29, 2021
Messages
37
Reaction score
4
Age
51
They have no choice, but there will NEVER be a third party DJI battery for the Inspire 1. Even if you reverse engineer the command set for the comms between the aircraft and battery, to produce a commercial product using that communication will end up in a lawsuit. DJI has always been adamant about protecting their IP and that protocol is still used in many other drones they produce.

First things first, i have no intention to commericalise it. I just want to be able to continute to use my inspire1 drone.

I originally went into this looking to do it for commercial reasons (see a need, fill a need and make a profit), and in doing so have a lot more invested in this than most.

I can understand that. I do similar things.. In fact its largely what i do. But not on this one. This ones very much strictly a hobby affair!


Now that doesn't mean I won't EVER share what I know, but I need to make sure that the information I have isn't subverted and used to "pump peoples egos" which seems to be the modus-operandi for those that wants hits on youtube to make money for themselves, as well as making sure people don't half-hack a "TRUE" solution in place and lead a whole lot of others down the wrong path.

You've summarised nicely what i felt when reading and watching videos.. A lot of half baked info, an lot of 'you dont' know what your doing, but i do, and i'm the greatest'... Its a bit unusual.. I guess theres a bunch of folks who have snippets of info, and sniff the opportunity to make a buck out of it. Your responses definately have passed the 'sniff' test a bit better than most. Measured and not making outrageous claims.

There is also the very REAL probability that people would use this information to reset cycle counts and dates/timers and sell people "like-new" batteries that are total garbage. Sorry, just look at the scheming and scamming goin on with eBay in regards to these batteries. I can tell you, if I was unscrupulous I could EASILY make a battery that will last only 5 minutes look and report like a new 20 minute TB48. After 3-5 cycles it would only report 1400mAh, but that is after the fact.

Yes. It will happen. Its a sad fact of how people behave. If i was buying batterys. ( trying to buy some 2nd hand ones right now, i'm assuming that the battery itself, is pretty much done,, i'm only buying them to get a few more BMS boards to see what i can figure out myself. I dont' really want to pull apart my only working one, and risk frying it. then i dont' have a fishing drone at all....

The few things I can verify is:

There is a "fused" set of counters that once started cannot be reset back to "factory" mode.

Thats not an uncommon thing. Coming from the other side of this, i udnerstand why Dji does this, it is really helpful for being able to check actual run times, when someone makes a warranty claim.. ( i only used it twice ).. verus the reality of 'I used it for 200 hours'...

I can also redo the capacity, cycling and charging parameters, including the cycle count. This allows me to change the capacity, the charge/discharge rates, even the bias used to balance the cells. I have built a 9000mAh battery as well as a 11400mAh battery and had them both work just fine, for reference. Packaging is a nightmare. I will say the "best" solution I have seen so far is the previously mentioned 12000mAh battery that was offered for a while. The big concern there is that the cell used are not LipoHV cells and are not rated for the continuous use the original DJI cells were.

For my particular use case i dont' need to up the capacity.. My flights are short.. 2-3minutes tops. more often than not less than 60seconds. But if we are running 4 or 6 lines, over a day, that might mean 40-60 flights.. Way more than a single battery has today. Being able to replicate the capacity of a 48 is more than suffiecnt for me.

3) All of the errors that display as far as cell status are NOT power fail modes set via the TI chipset. They are translated via the CPU. Now, that does not mean that DJI didn't just map a status bit in the TI tables to represent the failure modes, I am still doing some mapping to compare a set of failed batteries vs a non-failed battery to verify, it is just that I have not had a lot of time to finish that work.

4) DJI does use very high-quality cells. Most Lipo suppliers have a hard time producing these cells. I can also verify that almost ALL Lipo producers in China will state that DJI owns the exact specs for their cells and they CANNOT produce exact cells as a result. Now, I also know that the Swiss company shopped the Lipo manufacturers and convinced "someone" to produce them "like" cells for their rebuilds, so it CAN be done. I wouldn't want to hazard a guess at the quantities they had to commit to so they could secure that production. I also HIGHLY question the quality and viability of that rebuilt product for long-term use, since I have first hand experience with 3 different Lipo producers and they ALL have huge issues producing consistent quality.

This matches my experience with LiPo cells in general. You Think you have got a great supply and then the next batch is a bit differnet. :-( All that being said, its not an impossible problem to resovle, its just one that requries legwork to find the right ones... And i dont' have to find lots of them. If i cna get 10 battery packs it will keep me going for a long time.

which is a logistical nightmare to deal with the bad product.

A VERY GOOD REASON NOT TO DO IT COMMERICALLY!!

Now this is with totally "built" packs that are pre-soldered, but anything less (such as individual cells and PCBs) is a rebuilders nightmare unless you are charging 2x what DJI was charging for them, which they are not.


My opinion for what its work, is that the rebuild approach is fundementally flawed and its not an option that will last much longer.. theres not an endless supply of BMS boards!

Lastly, I can verify I have, on hand, 4 *NEW* TB48 batteries. I won't explain what/where and how I got them, but I might just share this source at some point here. All of these batteries have production dates of the cell packs of 10/2020 thru 11/2020 and serialized dates of the complete battery of 12/2020 for all. I will also state that I did not pay over $400 for any of them either. I won't state how much I paid, nor the sourcing (for now). Again, this is because I am more concerned of the source changing and limiting the availability and I know too many people "in the profession" that rely on these for "paying work" that are redoing their stocks as I type this that I would prefer to "get what they need" before I go public with this information.

II can understand staying mum about your sources.. Its a limited resource, and if the demand gets too high your in a world of pain! Many folks will of course just say, prove it, out of selfish ambition! IT woudl be the easiest option for me just to buy some.. Time is valuable.. But its probably only a stop gap measure as that supply will dry up as well....

The inspire1 is a great machine though, and as batterys become less avaiable more of the machiens will become avaialble for sale cheap. and if you have a way to keep up with batterys, you have a way to fly good drones dirt cheap. ( thats almost a song! )...



But Based on what i know so far, the only really vialble approach to my problem will be to make my own board.. figure out the coms between the battery and the rest of the machine, and find some suitable batterys.. I do recognise that is quite a complex set of problems to solve!
 
Joined
Dec 13, 2015
Messages
931
Reaction score
497
Age
74
... Sorry to be so cryptic and evasive, but I would hope I explained exactly why I am doing such for now ...
Actually, just the opposite, Brian ... Undoubtedly you know much more about all this stuff than most of us, but your intentions are unclear. Are you working on some commercially available solution, which will not collide with DJI's intellectual property? This may explain hesitation to share details of your work, naturally. Are you planning to sell your knowledge in future? In what form? So many questions ...
 
Joined
May 29, 2021
Messages
37
Reaction score
4
Age
51
Actually, just the opposite, Brian ... Undoubtedly you know much more about all this stuff than most of us, but your intentions are unclear. Are you working on some commercially available solution, which will not collide with DJI's intellectual property? This may explain hesitation to share details of your work, naturally. Are you planning to sell your knowledge in future? In what form? So many questions ...
Can only take him at face value... Life on the internet.. So far hes provided me a few interesting titbits of information for which i'm thankful.
 
Joined
May 29, 2021
Messages
37
Reaction score
4
Age
51
I just parted with US$349.00 for a 'Original DJI Inspire 1 TB48" From a vendor in China, who is a legitimate DJI Dealer there. For 10+ units they want $299 for them. Its a bit of a punt i know, but we'll see how it pan out.

Heres a link.

825081718/Original_DJI_Inspire_1_TB48_Intelligent_Flight_Battery_5700mAh_6S.html?spm=a2700.shop_index.82.7.20ca1afcyCYSHV
 
Joined
Jan 16, 2021
Messages
178
Reaction score
77
Age
51
I just parted with US$349.00 for a 'Original DJI Inspire 1 TB48" From a vendor in China, who is a legitimate DJI Dealer there. For 10+ units they want $299 for them. Its a bit of a punt i know, but we'll see how it pan out.

Heres a link.

825081718/Original_DJI_Inspire_1_TB48_Intelligent_Flight_Battery_5700mAh_6S.html?spm=a2700.shop_index.82.7.20ca1afcyCYSHV
Actually, those are "old stock" batteries. Already been down that path as well. You will find dates to be in the 2017/2018 range for those. Honestly $349 isn't a bad price for a brand new one, but being older stock, just be aware it is probably only going to offer 85-90% capacity.

As far as my intentions, again, I will most likely "share" what I know when it is the proper time. To do so now would cause a flood of purchases and issues that would end up causing problems for some and could result in unavailability for others. I do know that people would start taking advantage of others. As I said already, look at how much people are charging for used Inspire 1 batteries. That kind of gouging would only get worse as people change existing battery parameters and try to pawn off garbage as useable "newer" batteries. I am trying to prevent that as much as possible.

As far as "profiting" for myself, as it stands anything I would want to get involved in would have to be something with serious volumes. Making small money here and there is not worth the hassles involved. I would need to secure orders in the hundreds to make purchases viable in volume.
 
Joined
May 29, 2021
Messages
37
Reaction score
4
Age
51
Well, if they are 'old stock' so be it. The are the best avaialble option to me. Its what it is. You might have a better source ( i will take you at your word, but its not possible for me to get to this source you may have. .

Its not the end of the world, to have spent a few dollars. It does however give me some batterys i can start investigating with. And who knows might be able to do something interesting with, and learn what I need to power my drone up, to take it fishing for a lot longer. This is an interetting problem and one that just intriges me.

It does intrigue me that nearly every battery modder thread i've read almost follows the same format.. Theres someone trying (or was trying) to commericalise a solution. And thats fine if folks want to.. And good luck to them. I just cant' see how they hope to make any coins out of it.
 
Joined
Dec 13, 2015
Messages
931
Reaction score
497
Age
74
This is an interetting problem and one that just intriges me.
And there's nothing wrong with such approach. You'll go follow exactly the same path I've made, starting some 2 years ago ... Until I reached a conclusion that the issue is just too complex and the resources are not really available in this part of the world. The whole project requires top notch DIY skills and code hacking/writing knowledge way above and beyond feasible level ...
It does intrigue me that nearly every battery modder thread i've read almost follows the same format.. Theres someone trying (or was trying) to commericalise a solution. And thats fine if folks want to.. And good luck to them. I just cant' see how they hope to make any coins out of it.
The most popular and obvious (one may think) solution, employed in endless incarnations since early days of Inspire 1, is a parallel auxiliary battery (or two). This approach may work when a particular type of auxiliary batteries is used and the original battery is in good shape. In every case I know, however, the drone was transformed into a clumsy, heavy fuel tank, capable to stay airborne for perhaps 10 minutes more, but the payload was reduced to a pack of cigarettes ...

This scenario, however, faded away with ageing original batteries. At some point the auxiliary batteries are providing power to charge weak TB's during flight, rather than providing power for flight. Therefore you always need a healthy main battery and "smart" circuitry to monitor the whole system. You may attempt to expand the capacity of battery pack, but the board must be programmed to accept different parameters. By far no one was able to reverse engineer (counterfeit) this board or design/manufacture an equivalent which can be sold as a kit. How would you program a particular assembly remains the problem within "mission impossible" category ...
 
Joined
Jan 16, 2021
Messages
178
Reaction score
77
Age
51
Well, I can tell you all the problem with adding "extra" parallel batteries is simply an electrical engineering problem with the way people went about it.

I have run a parallel battery without the possibility of putting the original battery into "charge mode". The issue is that even if that is done, it is not proper and runs the risk of bricking the main battery since you need to modify the battery to make it work, which would involve a small circuit.

I can explain how to make it work, but that would end up with people bricking their batteries, thus my hesitation in doing just that.

Actually, there is two ways to accomplish this. The other way doesn't require a circuit to make it work, but still needs some sort of "safety" in case there is a battery failure. Basically that means a small circuit needed to electronically disconnect it. I have done this method as well and it has worked just as good as the other way.,

The big issue I see is that too many "RC geeks" want to plug a battery in the way they did with their heli project. Drones are at the point that any sort of hacking like that basically makes it unsafe and it would be irresponsible to tell people how to do something that could result in even a single "fall from the sky" event which could result in property damage or personal injury. The Inspire 1 is NOT a small bird where you can muck around with power sources and a crash is the loss of the aircraft. An Inspire 1 WILL do some serious damage.

I have ZERO doubt that if certain popular drones become unsafe they have the will and means to literally BAN them from the skies. To date only Mavic drones have had run ins and they are much smaller, but if you notice DJI is leaning towards getting away from the Mavic name, and I am certain it has to do with all the issues people have caused with models of that moniker.
 
Joined
Dec 13, 2015
Messages
931
Reaction score
497
Age
74
I have run a parallel battery without the possibility of putting the original battery into "charge mode". The issue is that even if that is done, it is not proper and runs the risk of bricking the main battery since you need to modify the battery to make it work, which would involve a small circuit.

I can explain how to make it work, but that would end up with people bricking their batteries, thus my hesitation in doing just that.
Now, this statement is confusing ... Is this "small circuit" of yours actually working? Will it eliminate the risk of mid-flight battery bricking?
 
Joined
Jan 16, 2021
Messages
178
Reaction score
77
Age
51
Now, this statement is confusing ... Is this "small circuit" of yours actually working? Will it eliminate the risk of mid-flight battery bricking?
Yes and yes. Not confusing at all. I have both methods working. Tested over 2-3 days with a dozen or so charge/discharge cycles. And yes, there is no bricking with either method.

But again, it would be completely irresponsible to give it out for the reasons I outlined. I will say, 3 years ago it would not have been an issue, but with how politicized everything is today, it would be irresponsible... Progress seems like a change in teh wrong direction at times and for certain things. This is one of them.
 
Joined
Jan 16, 2021
Messages
178
Reaction score
77
Age
51
Sorry, I guess the original way I stated it *WAS* confusing. Basically I go with the lowest common denominator when trying to determine if people will properly follow instructions or not. In this case I figure people would bypass the circuit (or get it wrong) and totally brick their batteries.

If I could assume everyone would do the "safe" thing, I would be much less hesitant. But, we all know, that most people are lazy, opportunistic and will cut any and all corners whenever possible and have less than ideal outcomes and then blame someone else.

To fully clarify, yes, I have the small circuit built to not brick the battery in the first method. I have used that method and the second method, both with success.

I have NOT built the safety circuit for the second method to monitor the extra battery that is in parallel for common failure modes.
 
Joined
Dec 27, 2020
Messages
22
Reaction score
10
Age
53
Location
Waco, TX
Anyone familiar with (drop shipping?) services that ship DJI-like batteries to the USA from the website taobao? I can confirm the following will not: cssbuy and tbfocus. Still waiting for confirmation that superbuy will not, however they likely do not.
 
Joined
Jan 16, 2021
Messages
178
Reaction score
77
Age
51
Also, if you are wondering, I was testing with a complete TB47 battery packs as the "secondary battery", but without the plastic casing and BMS. Affixing an extra battery is something of a PITA.

And yes, it is a matter of diminished returns in regards to weight vs power vs time.
 
Joined
May 29, 2021
Messages
37
Reaction score
4
Age
51
The whole project requires top notch DIY skills and code hacking/writing knowledge way above and beyond feasible level ...

I'm a electronics engineer,I spend my life designing control systems for all sorts of thigns from roller coasters to hydrodams. I own a well equiped electronics lab and factory, and have tools and development kit at my disposal, thats probalby a bit more advanced than most folk home kit.. Though that being said, i'm constantly amazed at what hobbist/hackers produce with the bare minimum of gear. My 5c worth (a little off topic) is that not having better/more gear in most cases does not stop you from doing somethign. It just a matter of time.. We have millions of dollars of kit in the lab/factory, and its endless, there is ALWAYS somethign that we need! ( or so we think )..

We'll see what we find...


At some point the auxiliary batteries are providing power to charge weak TB's during flight, rather than providing power for flight.
Theres a whole bunch of reasons why this problematic.. If you look at the physics/chemistry of the batterys, and the effort that teh BMS goes to keep cells balanced in a pack you'll see why this is a flawed process.. You 'd struggle to keep it all in balance... and the added weight it adds defeats what i'm doign anyway..

For me, if i could, i'd even consider flying smaller but lighter batterys to up the payload i can carry.. ( i'm wantiugn to use mine to carry stuff ( fish hooks! ).. Remembering my flight times are very short ( 3minutes is a LONG time for this operation )
 
Joined
Dec 13, 2015
Messages
931
Reaction score
497
Age
74
Also, if you are wondering, I was testing with a complete TB47 battery packs as the "secondary battery", but without the plastic casing and BMS. Affixing an extra battery is something of a PITA.

And yes, it is a matter of diminished returns in regards to weight vs power vs time.
So, at this moment it will be possible to plug in a specific 6S pack with your "safety circuit" and fly inspire 1 without worrying? That's excellent news! I have new cells (apparently for TB47), which I may assembly into a half size "backpack" in 6S1P configuration, reinforcing the original healthy TB47. This may be the proper balance between too heavy double TB47 configuration and rather weak single TB47. What do you think?
 
Joined
May 29, 2021
Messages
37
Reaction score
4
Age
51
Now, this statement is confusing ... Is this "small circuit" of yours actually working? Will it eliminate the risk of mid-flight battery bricking?
'Small' Circuit may be as simple as a FET that functionally operates a diode to prevent energy moving from parrallel batterys to the 'Main' battery.. Theres a bit more to it than that possibly in practical sense..


However, how the BMS perceives the batterys its seeing is another topic entirely..
 
Joined
May 29, 2021
Messages
37
Reaction score
4
Age
51
So, at this moment it will be possible to plug in a specific 6S pack with your "safety circuit" and fly inspire 1 without worrying? That's excellent news! I have new cells (apparently for TB47), which I may assembly into a half size "backpack" in 6S1P configuration, reinforcing the original healthy TB47. This may be the proper balance between too heavy double TB47 configuration and rather weak single TB47. What do you think?
I think that having external cells in parrallel the the primary is never going to be particually optimal and could cause unexpected and untimely faults. I fly my drone over salt water.. not someting i really want to chance.
 
Joined
May 29, 2021
Messages
37
Reaction score
4
Age
51
Quick poke around with a battery pack today, a scope, and a $30 bus pirate was interesting. Theres quite a bit going on... first task is try to draw some schematics of the battery pack. theres quite a need to be careful, the battery packs got pleny of scope to deliver a decent amount of energy if you were to short it out. Will have to cut a bit of polycarb, to mask out the battery on the bench, to create a bit of a sheild if it did go pop. I've seen what can happen.. Best to be a bit cautious. The vast majority of the compoents are indentifable, and the chipsets are all current parts from their various manufacturers.


 

New Threads

Members online

Forum statistics

Threads
21,695
Messages
207,234
Members
31,693
Latest member
Johnnieyaz