- Joined
- May 29, 2021
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- 38
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- 53
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!