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.
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.
