Awesome! I'd love to see the progress as it moves along!
The ULTIMATE Inspire 2 battery charger
- Thread starter AcesAreWld
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It's not going to happen quickly, but I'll be sure to report back here when/if I end up putting something together.
Which charger is this one? I cannot find it from the label you are showing but I am interested!
Looks like Dji have been listening and made one similar!
The DJI Battery Station: An Exclusive First Look
The DJI Battery Station: An Exclusive First Look
Yup. Thiers is still not really available (that I know of) and does not charge as quickly as mine does. It only charges 2 batteries at full speed whereas mine can do 6 at full speed -- and actually faster. Theirs is also VERY loud with the fans when it is charging in it's "fast mode". But more than anything is the fact that mine is designed to run off a car or wall outlet. That was the whole point for me was mobile charging from a car battery instead of needing to bring along a gasoline generator. Theirs ONLY works off AC wall power.
Yes, yours is better for sure. Theirs is limited being AC only. I don't have the time to build one like yours though so maybe theirs is the next best thing... ?
I've been following this thread, and every other thread on mobile charging of Inspire 2 batteries. I'm fine with only charging one pair at a time. I have three pairs so that gives me over an hour of flight time before I am out of batteries. I'm building a supply that runs off the car battery, directly connected and not through a cigarette lighter, and should charge two batteries in about 40-45 minutes. I'll time it and see. I'm using two of the 600 Watt DC to DC step up converters that @Dobmatt used in his charger and a couple of displays. Actually three displays, one for each battery showing voltage and charge current and one for the incoming 12v supply. It's small, about $100 all said and done, maybe a tad more and it fits my needs. @AcesAreWild, you have a power house, literally, but it's more than I need at this point. I'll post back when it's all done and let you know how it works. I've tested it on the bench so far. Headed to Iceland in three weeks and the little camper van will be my power source.
May I ask, how did you got around the charging without HUB problem? I Can't charge with the same cable and a power source.
Thanks!
Thanks!
@seahawk92 I'm following what others like @AcesAreWld did. I'm modifying this cable Buy Inspire 2 Remote Controller Charging Cable to use the connector that attaches to the battery and wiring that up to the output of my DC to DC converter. I first wired one DC to DC converter to the charging hub but that hub must limit the current that it draws. I was getting 5+ amps whether I had one or two batteries plugged in. So, I think if I run one DC-DC converter for each battery and limit the amps out to less than 8 that I'll be able to charge each battery at 7+ amps which is much quicker than 5+ shared between two. I get the cables soon, once I have it wired and working I'll post an update.
Thanks for the info. When i do the same the batteries won't charge. IF i do the same but with the charging hub, it works. Weird. :-(
@seahawk92 , Hmmn, well maybe I'm in for a surprise. Either way, I'll let you know how it turns out.
@seahawk92 @AcesAreWld @Dobmatt here is what I've found.
@seahawk92 To get the batteries to receive voltage using this connector Buy Inspire 2 Remote Controller Charging Cable I found there is one pin on the connector that must be removed. I believe it is grounded and that the battery won't charge if it sees ground. You can use a continuity meter or ohm meter to find it. The pins are symmetrical, power at the middle four I believe and ground at the two on each side, just outside of those four. Then you'll find another pin that is ground. Not very elegant but I used needle nose pliers and twisted it off since the connected looked like a molded connector. I'm not sure how to attach a pic.
So now it's charging, but I'm having a problem. I'm using two of these DC to DC step up converters: https://www.amazon.com/gp/product/B00E8D7XYG/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
I have a 10 AWG cable going five feet from a deep cycle 12V battery to my box with a 30A fuse inline. I run the power through a 30A switch and then to the two boards. I use the outputs of the boards separately to the battery connected mentioned above. I set the voltage to 26 volts and the output current to 6.9 amps. I blew the 30 Amp fuse.
I believe input current is = output power / efficiency factor / input volts. With two modules that would be: = 2 * (26V * 6.9A) / 0.95% / 12V = 31.6 Amps OOPS, so I adjusted the current down to 6 amps which would be 2 * (26V * 6.0A) / 0.95% / 12V = 27.4 Amps. I'm still melting/blowing 30A fuses and my 10 AWG wire is getting hot. Tomorrow I'll set the current to 5 amps and see how it does. If I just power the charging hub then it limits to the current to 5 amps between two batteries so even if I have to run these DC to DC converters at 5 amps I'm still twice as good as using the hub.
@seahawk92 To get the batteries to receive voltage using this connector Buy Inspire 2 Remote Controller Charging Cable I found there is one pin on the connector that must be removed. I believe it is grounded and that the battery won't charge if it sees ground. You can use a continuity meter or ohm meter to find it. The pins are symmetrical, power at the middle four I believe and ground at the two on each side, just outside of those four. Then you'll find another pin that is ground. Not very elegant but I used needle nose pliers and twisted it off since the connected looked like a molded connector. I'm not sure how to attach a pic.
So now it's charging, but I'm having a problem. I'm using two of these DC to DC step up converters: https://www.amazon.com/gp/product/B00E8D7XYG/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
I have a 10 AWG cable going five feet from a deep cycle 12V battery to my box with a 30A fuse inline. I run the power through a 30A switch and then to the two boards. I use the outputs of the boards separately to the battery connected mentioned above. I set the voltage to 26 volts and the output current to 6.9 amps. I blew the 30 Amp fuse.
I believe input current is = output power / efficiency factor / input volts. With two modules that would be: = 2 * (26V * 6.9A) / 0.95% / 12V = 31.6 Amps OOPS, so I adjusted the current down to 6 amps which would be 2 * (26V * 6.0A) / 0.95% / 12V = 27.4 Amps. I'm still melting/blowing 30A fuses and my 10 AWG wire is getting hot. Tomorrow I'll set the current to 5 amps and see how it does. If I just power the charging hub then it limits to the current to 5 amps between two batteries so even if I have to run these DC to DC converters at 5 amps I'm still twice as good as using the hub.
@seahawk92 I turned the current limit down to 5 Amps today on both channels and it worked well. Didn't blow fuses. It took 30% batteries (two at once) roughly 40-50 minutes to fully charge and shut off their charging so that isn't anything to brag about but it is quite a bit faster than using the hub. I found it worked best to plug in the batteries and then turn on the charger. I also had a connector in the main power from the battery and found it had too much resistance, i.e. getting hot, so I rewired and took out the connector. I think the 5Amp is a limitation of the DC to DC converter, so a different one may allow higher amperage. There's a statement in the description of the converter that says "Output power: = Input voltage * 10A, such as: input 60V * 10A = 600W,if need more output power, such as need the output to 15A,two modules can be used in paralle, the current of each module can be adjusted to 8A. " which I took that to mean that is all the power you'll get out. But I'm starting to think you need to limit power to that or it starts to draw too much current. So, 12V in times 10A = 120 watts. 120 watts divided by 26 volts = 4.6 Amps. Hope that helps.
@daveness -- Good information there. I am using basically the same DC-DC converters as you are -- one converter per battery pack. When I use my AC power adapter the input is 24V and those DC-DC step-up converters only have to boost the voltage 1-2 volts to 26.1 -- meaning they're hardly working at all. It IS important that they regulate the current however, as the DJI batteries will not take more than 10 amps before shutting down to prevent charging too fast. For me, off either the 12V car battery OR the 24VDC (coming from the AC transformer) I can charge the batteries at 9+ amps (I never go above 9.5 amps, just to prevent them from shutting down and increasing the charge time). On my 6-channel setup I can charge all 6 batteries from 20-30% to 100% WITH BALANCING in about 35 minutes. For ALL of my wiring I figured out what was the required gauge and then went at least one gauge LARGER. Everything on my charger was over-engineered and designed to operate at no more than 60% of the rated maximum for each component used. It is for that reason that I can charge so much so quickly, over and over again -- and not worry about heat, melting anything, blowing fuses, etc.
@AcesAreWld I could see charging that fast at 24V input, I'm surprised you can with 12V input. I wonder what is different, perhaps wire size as you indicated. But those DC to DC step up converters have a 20amp input fuse. Hmmn. I'm using 10awg from battery to modules and that is where it was getting hot. Using the formula for 24V in, then the output power would be 24V * 10A = 240 watts, divided by 26 votes leaves 9.3 amps, yeah I can see it for a 24V input. I wonder, do you have a fuse from the battery to the modules? Or anyway to know how much current you're pulling between the battery and module(s)?
Remember, when you cut the voltage in half (12V input instead of 24V input) you DOUBLE the amperage required on the input... So when I say I can still charge at about 9 amps on the 12V battery, that is roughly 18 amps on the input side (plus any inefficiencies). That is still below the 20A max for the inverters. So staying below 20A, plus the massive amount of cooling I have, plus the fact that a full 9A draw only happens when the Inspire Battery is at it's LOWEST point (and the amperage slowly goes down as the battery charges up) makes sure I am good. Like I said, I figured out all my maximum amperages and then went at least one wire gauge LARGER than would be needed.
It definitely charges more/faster on AC input (which comes into the boost converters at 24VDC) but the time difference between [call it] 8.5 amps on 12V versus 9-9.5 amps on 24V is a minute or two. It's hardly noticeable at all in the real world when charging up those 6 batteries very quickly compared to the OEM options.
Forgive me if I missed it somewhere in this thread, but is there any chance you have a parts list for this build? I would love to make one similar to build into my command vehicle for our drone. Having DJI charging hubs as the bottleneck in our flight time is not desired...
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I'm still in the "bread board" beta testing of a similar set up. The exception is that I need to vary voltage so that I can charge M600/Inspire batteries, Mavic batteries and/or P4P batteries. I'm using massive, highly efficient boost converters (voltage ripple < 50mv), which, so far, have remained very cool, even when charging TB48 batteries @ 105 watts.
Ironically, I was looking at a 1510 case just yesterday. Nice set up! I like that fact that you use jumper cables...though there are certainly caveats to that kind of set up (that I'm sure you're well aware of).
I have my rig set up with #8 conductor, but clearly if I'm going to super quick charge 6 batteries (150+ watts/each in theory), I might have to step that up. Like your rig, I think it would be wise for me to limit current draw to < 100 amps. I'd actually like to keep it under 80 amps. I'm not sure what my Honda Civic alternator is rated at, but I'm sure it's not 90 amps...probably closer to 60 amps...even less @ idle.
Initial field tests have gone well. Nothing gets hotter than 84° F.
Unlike your XT60 plugs, I have opted for banana plugs. This choice wasn't so much a conscious decision as much as it what was in my parts box...<;^) That said, I think they will work out well. They have a very positive connection...the caveat obviously that they CAN be connected backwards by accident...something I undoubtedly will never do....<;^)
In this photo, set up for P4P batteries.
Once this rig proves itself in the field, I'll package it nicely.
D
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I like the fact you can charge various batteries...very cool.
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I had originally set this up to charge 3 batteries, but now with the M600, I'm going to have to step it up for 6. I'm going to need a bigger case.
D
