Charge Inspire Batteries with RC Charger

Granger · Jan 19, 2015

hey, So. I was nervous to try this, But it worked. well, looks like its working.

Made a cable to run from the charger to the battery. Charger is a "rc Hitec x4 charger"
Did cut the transmitter/battery spare cable supplied to make it work.
All seems good. Im now gonna make new connectors so I can charge everything from one charger.

Check out the picture.

What do you guys think?

NEJO/Wisconsin · Jan 19, 2015

Are you in full scale production seriously though let me know how it wrks I wld interested in doing it

Helnet · Jan 19, 2015

Have you tried to charge your batteries in a full process and fly if?

I made this for my phantom 2 but it does, not work.

Granger · Jan 19, 2015

Ok So this is what happened:

The Original charger for the inspire outputs:
26volts
3.8amps

So I set my RC charger to
24volts (As high as it could go)
3.8amps (Was at 3.8a, but jumped to 2.2a when charge started)

So it charged up as is should (Although I had to "turn the battery on" to start the charge.
After about an hour charger said full, But battery's last light was still blinking. So it was almost full, just not 100%

I had noticed that my charger defaulted to 2.2amps while charging, Dont know why.
So in conclusion, This method does work, Maybe I just have the wrong kind of charger?

Still beats waiting for everything to charge off 1 charger.

So Guys try it out figure out which method is the best because $55 for a dji charger is crazy!

rilot · Jan 19, 2015

Your charger can only do 2.2A max at that voltage because it's only 50W per channel. I = P / V so I = 50 / 24 = a bit over 2A.
You want to charge using a Pb program not LiPo as the stock DJI charger is literally just a 26V power supply. There is no intelligence in it at all. It's all in the battery. I've tried this with my iCharger 308B and it works. 26V Pb program and 5A no problem.

Granger · Jan 20, 2015

rilot said:
Your charger can only do 2.2A max at that voltage because it's only 50W per channel. I = P / V so I = 50 / 24 = a bit over 2A.
You want to charge using a Pb program not LiPo as the stock DJI charger is literally just a 26V power supply. There is no intelligence in it at all. It's all in the battery. I've tried this with my iCharger 308B and it works. 26V Pb program and 5A no problem.

you sure about 5amps?
The dji one goes to I think 3.8 amps?
I would think that, as per "RC" rule of thumb u would charge a 4500mah battery at 4.5amps? Or am I wrong?

rilot · Jan 20, 2015

At the end of the day, the charger will only supply what the battery will draw. I set it to 5A which is just over 1C and let it get on with it.
I charge my 6S lipos for my S800 at 12A which is 2C for those.

Granger · Jan 20, 2015

haha, so me being a rc dumbass, What exactly are you saying?
What kind of power supply do i need for the inspire battery? Or which rc charger would work?
(
4500mAh
99.90Wh
22.2v
)

rilot · Jan 20, 2015

To be honest, I'd just stick with the stock charger. Even though I can use my iCharger 308b, I'll probably keep using the stock DJI chargers for the Inspire. I'm quite risk averse.

If you do want to spec something then anything that can do a Pb program at 26V and is 100W per channel or more will give you around 4A. Ideally you want more than 100W to leave you some headroom.

Keks · Jan 20, 2015

Hi guys, i think that word "li-po" little confusing you. Usualy in RC world you need charger with balancer for your li-po batterys. Inspire have "intelligent" battery, by that i assume that they mean it have charger, balancer and monitoring all inside allready.
This is simmilar like yours laptop battery, you dont need fancy li-po charger to charge your laptop. I think that all you need to charge Inspire battery is constant DC voltage (26,3v) power suply and max amperage 6,83A (180W). Its very dificult to find with that kind of voltage power supply. Only available what i found with quick search from internet, is variable voltage DC power supply units. They are bigger, heavier, dont have Inspire battery compitable cabel with them and not cheaper than original charger. Maybe only one thing is better, that you can find 5A or 10A power supply unit, so you have less charging time compare to original charger.
Maybe I am all wrong with that idea, thats just my logical thinking. Its defenetly safer to use original DJI charger, its not so expensive compered to Inspire itself.

Granger · Jan 20, 2015

Keks said:
Hi guys, i think that word "li-po" little confusing you. Usualy in RC world you need charger with balancer for your li-po batterys. Inspire have "intelligent" battery, by that i assume that they mean it have charger, balancer and monitoring all inside allready.
This is simmilar like yours laptop battery, you dont need fancy li-po charger to charge your laptop. I think that all you need to charge Inspire battery is constant DC voltage (26,3v) power suply and max amperage 6,83A (180W). Its very dificult to find with that kind of voltage power supply. Only available what i found with quick search from internet, is variable voltage DC power supply units. They are bigger, heavier, dont have Inspire battery compitable cabel with them and not cheaper than original charger. Maybe only one thing is better, that you can find 5A or 10A power supply unit, so you have less charging time compare to original charger.
Maybe I am all wrong with that idea, thats just my logical thinking. Its defenetly safer to use original DJI charger, its not so expensive compered to Inspire itself.

Yes, you are right, Dont need a charger, just power supply.
I just bought a 24v 4amp, 96w power supply for like $25,

So will test and let u guys know!

Keks · Jan 20, 2015

I think that 24v DC is not gonna be enough. Inspire battery is 6s lipo, fully charged 6s voltage is 25,2v plus i thing that electronic inside battery drain little of that voltage, thats why original charger have 26,3v. You cant charge with 24v the battery to full capacity.
I have one other interesting question, DJI battery specs states that max charging power is 180w. Should it be max power output for power supply unit or is it max power that battery can consume?
If it is max that battery can consume, then we can buy one power suply unit with 20A current rate and connect to it three batterys at the same time. That gonna charge them very quicly.

rilot · Jan 20, 2015

Keks said:
Hi guys, i think that word "li-po" little confusing you. Usualy in RC world you need charger with balancer for your li-po batterys. Inspire have "intelligent" battery, by that i assume that they mean it have charger, balancer and monitoring all inside allready.
This is simmilar like yours laptop battery, you dont need fancy li-po charger to charge your laptop. I think that all you need to charge Inspire battery is constant DC voltage (26,3v) power suply and max amperage 6,83A (180W). Its very dificult to find with that kind of voltage power supply. Only available what i found with quick search from internet, is variable voltage DC power supply units. They are bigger, heavier, dont have Inspire battery compitable cabel with them and not cheaper than original charger. Maybe only one thing is better, that you can find 5A or 10A power supply unit, so you have less charging time compare to original charger.
Maybe I am all wrong with that idea, thats just my logical thinking. Its defenetly safer to use original DJI charger, its not so expensive compered to Inspire itself.

You are correct. This is why I'm using a Pb program which is essentially just a dumb power output from my charger at 26V.

Muscleflex · Mar 11, 2015

Very interesting... anyone else doing the same?

sirnikolas · Mar 11, 2015

I've got 2 Dji charges and I'm looking at buying a 3rd. I spent $3769 Australian dollars to buy the I1, another $380 for 2 batts and $689 for the Air 2. Whats another $65 dollars on top of all that? And best off all, it's all covered by Dji's warranty. Except for the Air 2 of course! And it's on their supported list!!
Aaaaa piece of mind

Charlie Dinge · Jul 28, 2015

Granger said:
hey, So. I was nervous to try this, But it worked. well, looks like its working.

Made a cable to run from the charger to the battery. Charger is a "rc Hitec x4 charger"
Did cut the transmitter/battery spare cable supplied to make it work.
All seems good. Im now gonna make new connectors so I can charge everything from one charger.

Check out the picture.

What do you guys think?

Does it matter how you connect the wiring from the x4 to the DJI connector? In the DJI connector, there is the inside white wire and the outside "sheath" wire. What connects to black and what connects to red? Maybe im thinking to far into this.

ajohnsonlaird · Jul 28, 2015

I've been pondering the same question as I have eFuel 1200 watt power supplies driving Hyperion SuperDuo 720's.

There is a Pb battery type setting on the Hyperion. For that preset you can select a battery capacity of 5.5 Ah, and you can limit the charge current to 5.5 Amps, but the Hyperion then only allows you to specify a battery voltage of 24v (in contrast to the TB47/48 which are 22.8v). Worse yet, the charging voltage is 27.6v -- significantly higher than the 26.3v from the DJI supply.

The advantage to being able to use the Hyperions would be that they can charge and discharge. For LiPo's they can also take to storage voltage but I doubt that option is available for Pb chemistry.

The other issue is that the Hyperion's will not let you charge a LiPo unless you have a battery balance connector attached -- which is a perfectly reasonable restriction for "normal" LiPo charging.

I had also considered using a current limiting bench power supply where I could set the voltage to match that of the DJI power supply and limited the charging current to 1C or 2C for the Lipo's lurking in the TB 47/48.

But, in the end I got cold feet (from the fear of hot batteries?) and bought an SPC4500 Smart Charger. The downsides with the SPC4500 product are a) you cannot do a full deep cycle to recalibrate a battery -- it will not deep cycle unless the charge is < 30% and b) you cannot use it to take a fully charged battery to a reasonable storage level but have to rely on the TB 47/48's time-out/discharge logic.

Andy.

Alexei Karam · Sep 24, 2015

Guys, be very careful, all what you are stating here is incorrect and you are going to toast/damage your batteries if you go that route. Yes the DJI battery is smart, it has an electronic circuit that monitors each cell and balances the cell voltages. In addition it stores the number of cycles the battery has been used, calculates remaining flight time/capacity and protects from over/under voltage/current and overheating but that's it! DJI's charger is not a simple constant voltage power supply, it is a CC-CV power supply (cc for constant current, cv for constant voltage)
When you start charging, you are in CC mode at first, i.e. the max current of 3.83A is constant and the voltage starts to rise from approx. 19.8 volts for a fully depleted battery (i.e. 3.3 volts/cell) till the voltage reaches the maximum of 26.3 volts (4.38 volts/cell) at this point the current starts to drop and the voltage remains fixed (CV mode). When the battery detects the the voltage is 26.3 and the current dropped to < 0.2Amps (approx) charging terminates and the battery disconnects itself. There are some CC-CV power supplies that you can buy on AliExpress and other places that you can use with the I1 or P3 but I would not recommend anybody goes this route unless he has a strong background in electronics and RC otherwise you may run into trouble...

Henrik M · Nov 8, 2015

All you are talking about is correct but isn't the voltdrop and so on handled by the battery? The powersource is just that, a powersource...

Alexei Karam · Nov 9, 2015

Henrik M said:
All you are talking about is correct but isn't the voltdrop and so on handled by the battery? The powersource is just that, a powersource...

NO! It is not just any power source! It is a CC-CV power source, google it. Anyways you need to have some background in electronics to get it. If you dont, don't go that route, just use the original charger.
For example, if you get a normal 26volt 3.8Amp power supply and the battery is empty lets say at 19.8 volts, connecting the power supply to it will cause the power supply to burn out or shutdown.