The Mother of All Chargers?

[Kilrah]

Please note..... NOTHING will charge the Inspire batteries faster than they control themselves to be charged.

The battery does NOT set the current.

The super wonderful 4 bay power supply is NOT a charger.

It has to be, would be problematic otherwise.

If you were to hook up a 26.3 volt power supply that could deliver 100amps it would not charge the Inspire battery any differently or faster than the stock PSU because everything is regulated by the battery.

It will. The current will shoot up and the battery will just do a safety cutoff when it exceeds 10A or so. Max rated charge power is 180W or about 7A.

Higher current PSU's have been placed in line and the current still tops out at just about 3.9amps.

That is wrong based on both my own observations and other people's.

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I've posted all that info about 10 times, surprising people still insist in believing and posting the opposite.

 

[m00se]

I managed to buy two additional chargers last night at a marketplace, quite happy, they are defo genuine, so I got a plastic chopping board , and am currently cutting it to fit in the top of a peli case so that I can stand the batteries in and have a somewhat easy to use charging unit when out in the field, something that looks better than 3 batteries sat on a desktop with cables running to them

 

[m00se]

The battery does NOT set the current.


It has to be, would be problematic otherwise.


It will. The current will shoot up and the battery will just do a safety cutoff when it exceeds 10A or so. Max rated charge power is 180W or about 7A.



That is wrong based on both my own observations and other people's.

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I've posted all that info about 10 times, surprising people still insist in believing and posting the opposite.

funny that, I stuck mine on a 20A supply yesterday and it didnt fully charge, got to 24V and shut off, but never pulled more than 3.8 a

i wonder if there are some different batteries out there, or if the firmware upgrade changes the charging routine?

 

[rtb]

When you guys are comparing price, you need to compare 6 x DJI chargers and power cords and two USB chargers against this single unit. Plus it is not just a power supply. It has deep cycle function and meets all FAA and CE requirements.
This unit can do 4 x batts + 2 x RC and 2 x Tablets simultaneously.

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[mdomeny]

didnt they just take 4 pcs of dji chargers, hooked up a little lcd and aligned the cords and put in a bec for the usb socket... ???

 

[Kilrah]

24V and shut off, but never pulled more than 3.8 a

24V is just too low, has to be 26.3, regulated. Those extra 2.3V make a LOT of difference.

When you guys are comparing price, you need to compare 6 x DJI chargers and power cords and two USB chargers against this single unit.

That's only relevant if you actually need that. I charge my remotes every several flights and can do it on DJI chargers when not charging main batteries, so I don't really need it and 4 DJI chargers would do the job. USB chargers I always have a couple in my bag as well as a rechargeable power bank.

It has deep cycle function

Which according to the doc is not correct (stops at 15%). DJI recommends cycling down to at least 8%, and preferably until the battery shuts itself down. That makes sense too.

 

[The Editor]

The battery does NOT set the current.


It has to be, would be problematic otherwise.


It will. The current will shoot up and the battery will just do a safety cutoff when it exceeds 10A or so. Max rated charge power is 180W or about 7A.



That is wrong based on both my own observations and other people's.

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I've posted all that info about 10 times, surprising people still insist in believing and posting the opposite.

All I am seeing there (in your video) is you setting the max current to 7 amps. The battery then charges with no problem and then ramps down the current down to circa 500mA to finish off the charge. If it didn't the battery would be charging at constant current which would be VERY bad. The battery (internal charger circuit) MUST ramp the current down towards the end of the chargecharge cycle for topping off. The potential difference across then pack will peak at circa 4.34v per cell and the current will drop to finish off the charge (during the balance period).
Have you tried that same experiment at higher current setting on that PSU? Say 15 amps or so? If so, where did the current peak (at start of charge)? I would think it would stop at circa 180w/7amps irrespective of where you set your current limit. This would be because DJI would limit the charge rate to the C rating of the pack.
I will admit I was wrong regarding the max current the pack will take at 4amps as it will probably be limited to max charge current safe for the pack at 180w.
The supplied DJI brick though is nothing more than a power supply within maximum current capacity of 3.83amps.

 

[Daniel Mascheck]

I'll get one just like someone said the convenience!! Heck, got so much money invested, whats a few hundred more!

 

[m00se]

i would have got one if they were available, now i got some seperate chargers and am making something i probly wont bother, its a shame

 

[Kilrah]

All I am seeing there (in your video) is you setting the max current to 7 amps.

Firstly it's not my video, and secondly you missed a critical point - that the guy sets the PSU's voltage output to 26.3V at the start of the video.

The battery then charges with no problem and then ramps down the current down to circa 500mA to finish off the charge.

No, the battery simply reaches those 26.3V and current draw reduces in the CV phase, like any LiPo charge process.

The battery (internal charger circuit) MUST reduce

That's the point, it cannot, all it can do is ON/OFF. Which is why the PSU needs to be both voltage and current regulated (= "be a CC/CV lipo charger" just with an unusual end voltage).

Have you tried that same experiment at higher current setting on that PSU? Say 15 amps or so? If so, where did the current peak (at start of charge)? I would think it would stop at circa 180w/7amps irrespective of where you set your current limit. This would be because DJI would limit the charge rate to the C rating of the pack.

Again it's not me, but yes I did the same test and went up to about 9A, didn't try more. Some have reported the battery shuts down at 12 or so, but again doesn't regulate as it can't do so. Just stops everything for safety.

The supplied DJI brick though is nothing more than a power supply within maximum current capacity of 3.83amps.

Again that is wrong, it is a CC/CV supply which has been shown numerous times.

 

[rtb]

That's only relevant if you actually need that. I charge my remotes every several flights and can do it on DJI chargers when not charging main batteries, so I don't really need it and 4 DJI chargers would do the job. USB chargers I always have a couple in my bag as well as a rechargeable power .

This is a premium product for the professional market. Time is of the essence when you are on set and earning $$$$$$.

If it's not for you, stick to DJI chargers.

 

[m00se]

I think the battery must contain the current limiting hardware, most chargers have a power supply and a charging / balancing circuit. I would imagine that this is charging / balancing bit is in the battery in this case, has anyone ripped on open to examine the chips? I saw a video on youtube but it was in german so i didnt know what he was discussing

 

[Kilrah]

Yes and again it is not. The video above even demonstrates it.

 

[The Editor]

Firstly it's not my video, and secondly you missed a critical point - that the guy sets the PSU's voltage output to 26.3V at the start of the video.



No, the battery simply reaches those 26.3V and current draw reduces in the CV phase, like any LiPo charge process.



That's the point, it cannot, all it can do is ON/OFF. Which is why the PSU needs to be both voltage and current regulated (= "be a CC/CV lipo charger" just with an unusual end voltage).



Again it's not me, but yes I did the same test and went up to about 9A, didn't try more. Some have reported the battery shuts down at 12 or so, but again doesn't regulate as it can't do so. Just stops everything for safety.



Again that is wrong, it is a CC/CV supply which has been shown numerous times.

I think we'll have to agree to disagree here or else we will end up dizzy with cyclic argument/discussions.

I'm charge my four batteries with my four DJI power supplies ergo, I am happy....

 

[Kilrah]

There's no agreement or disagreement... There's one way it works and that's it. It's demonstrated in that video, I can make the same one if you want, it will show just the same and match what I'm saying.

 

[rimb05]

I've tested this battery myself extensively as well, to the point of taking it apart and tracing the basic circuit. Kilrah is right - the charging terminals go through a simple series of mosfets (switches), then directly to the battery. There's no current limiting going on. This battery uses a Texas Instruments BQ78350 battery management chipset. As soon as the circuit detects current on the terminals, it turns on the mosfets and leaves them on. I've been charging my batteries at 6A with a bench power supply with no issues. Keep in mind, charging lipos requires a current limiting power supply. You must keep the current limited or you'll risk fire. If you have a CC/CV power supply, set the voltage to 26.3V and the current to 5-7A and you'll be good to go. Probably don't want to charge with much more current than that (1C is 4.5A for the TB47 and 5.7A for the TB48).

 

[m00se]

there's my half baked effort of a charging case, It has 3 dji supplies cable tied inside, and a 12v supply to power 2 12v fans to try and keep some air moving through it, the connectors are just free floating, i may eventually epoxy them in and make it better, but it should do for now, all in one place and only one mains voltage plug to plug in....... easy peasy

 

[Daniel Mascheck]

Just got word back from the company that it will charge 4 batteries and also two controllers and two IPads. They are sending me tech specs later.

 

[rtb]

Just got word back from the company that it will charge 4 batteries and also two controllers and two IPads. They are sending me tech specs later.

I believe that's what I said in post #24 above.

 

[jon b]

Yikes. SO much fuss... Was there this much kickback over the P2 batteries and their chargers?
Be nice to charge everything at once with no overheating of the power supply. The DJI chargers are fine... They get pretty warm doing their job so a beefier power supply with a little logic thrown in to automate the discharge process can't be a bad thing.

Never understand why so many threads get so intense (also see negative) when discussing the pros and cons of companies getting into support for DJI products.