Can anyone explain why this portable M3 battery hub charging solution wouldn't work?

[Cammo]

I'm really struggling to figure out why this shouldn't work - a big LiFeP04 battery (about 100Ah) in a battery box like this
with a 65W or 100W PD cigarette lighter to USB-C charger (like below) plugged into the 12V cigarette lighter socket on this battery box.


The LiFePO4 batteries are 12.8V nominal but operate between 13.6V and 13V for 100% to 30% state of charge. Shouldn't the Mavic 3 battery hub plugged into this 100W PD type C port work well?

Thanks in advance,

Cam

 

[RocketBrew]

I have been using this for years with the P4P, recently upgraded with the 100Ah LiFeP04 battery.

 

[Cammo]

I have been using this for years with the P4P, recently upgraded with the 100Ah LiFeP04 battery.

View attachment 143269

I'm assuming you're charging the P4P from 240V inverter? The Mavic 3 batteries charge via USB-C PD.

 

[RocketBrew]

Correct, the 120v inverter is on the side of the battery case.



I also have the cigarette lighter adapter he shows - it works to charge the M3.

Samlex PST-300-12 PST Series Pure Sine Wave Inverter - 300 Watt https://www.amazon.com/dp/B00H8N97E2/ref=cm_sw_r_cp_apip_MqNgjDCMgpIwZ

I'm assuming you're charging the P4P from 240V inverter? The Mavic 3 batteries charge via USB-C PD.

 

[Cammo]

Correct, the 120v inverter is on the side of the battery case.

View attachment 143271

I also have the cigarette lighter adapter he shows - it works to charge the M3.

Samlex PST-300-12 PST Series Pure Sine Wave Inverter - 300 Watt https://www.amazon.com/dp/B00H8N97E2/ref=cm_sw_r_cp_apip_MqNgjDCMgpIwZ

So, can I clarify please? You've been successfully charging Mavic 3 batteries on the Mavic 3 charging hub using that cigarette lighter adapter plugged into your battery box's cigarette lighter socket? Sorry to need it spelled out but I think I've received a dud 65W Baseus car charger which isn't working properly. I've been told that it doesn't work because Mavic 3 batteries are 4C batteries and I couldn't figure out which was the problem - either a faulty car charger or that Mavic 3 batteries couldn't be charged using a combination of a LiFePO4 battery and a 65W car charger.

 

[RocketBrew]

I have used the Wotobeus 100w car charger to charge a battery in the drone and the RC Pro, but use the battery/inverter rig with the three charging bases in the case 99% of the time.

The trick is to understand how the PD (Power Delivery) spec works, this is not your standard USB. Key to making it work is a cable that has the PD chip in it so the two ends can negotiate. Without it, you get regular USB power.

The 65 watt power source is fine, that is what the DJI power brick provides. If you provide more power, the batteries will charge a bit quicker. Some have reported 83+ watts, but across three different power supplies, the best I have seen is 74 watts.



As I learned the hard way, not all PD cables are created equal, and many just don’t work as advertised. I also found an inferior cable that only worked when plugged in one way, flip it over and - nothing.

So, can I clarify please? You've been successfully charging Mavic 3 batteries on the Mavic 3 charging hub using that cigarette lighter adapter plugged into your battery box's cigarette lighter socket? Sorry to need it spelled out but I think I've received a dud 65W Baseus car charger which isn't working properly. I've been told that it doesn't work because Mavic 3 batteries are 4C batteries and I couldn't figure out which was the problem - either a faulty car charger or that Mavic 3 batteries couldn't be charged using a combination of a LiFePO4 battery and a 65W car charger.

 

[SkywalkerFeng]

I have used the Wotobeus 100w car charger to charge a battery in the drone and the RC Pro, but use the battery/inverter rig with the three charging bases in the case 99% of the time.

The trick is to understand how the PD (Power Delivery) spec works, this is not your standard USB. Key to making it work is a cable that has the PD chip in it so the two ends can negotiate. Without it, you get regular USB power.

The 65 watt power source is fine, that is what the DJI power brick provides. If you provide more power, the batteries will charge a bit quicker. Some have reported 83+ watts, but across three different power supplies, the best I have seen is 74 watts.

View attachment 143272

As I learned the hard way, not all PD cables are created equal, and many just don’t work as advertised. I also found an inferior cable that only worked when plugged in one way, flip it over and - nothing.

I use Wotobeus 120W car charger, with Baseus 100w USB-C charging cable. Together they output 87W to charge the battery for Mavic 3.

 

[Cammo]

I use Wotobeus 120W car charger, with Baseus 100w USB-C charging cable. Together they output 87W to charge the battery for Mavic 3.

View attachment 143276

Thanks for that good info. What do you have your Wotobeus 120W car charger plugged into? I'm guessing it's a car cigarette lighter socket? What about if it was a battery box containing a LiFePO4 battery, ever tried it connected to something like that?

 

[Cammo]

I have used the Wotobeus 100w car charger to charge a battery in the drone and the RC Pro, but use the battery/inverter rig with the three charging bases in the case 99% of the time.

The trick is to understand how the PD (Power Delivery) spec works, this is not your standard USB. Key to making it work is a cable that has the PD chip in it so the two ends can negotiate. Without it, you get regular USB power.

The 65 watt power source is fine, that is what the DJI power brick provides. If you provide more power, the batteries will charge a bit quicker. Some have reported 83+ watts, but across three different power supplies, the best I have seen is 74 watts.

View attachment 143272

As I learned the hard way, not all PD cables are created equal, and many just don’t work as advertised. I also found an inferior cable that only worked when plugged in one way, flip it over and - nothing.

Thanks for that info. I do quite a lot of live-streaming and my live-streaming switcher operates off 12V so I use a LiFePO4 30Ah battery which works like a champion for many many hours without missing a beat. I thought I'd double down on this and also take the opportunity to charge my M3 batteries with it too.



Hopefully I've just got a dud car charger or cable and the Wotobeus 100w car charger and a good cable will solve my issues. I did get this Baseus car charger/cable kit and would have thought it would work well but it doesn't work properly when connected to either this LiFePO4 battery or even directly to my car! I guess it's worth trying the Wotobeus 100w car charger then, got a link to cable that you'd recommend?

Thanks!

 

[SkywalkerFeng]

Thanks for that good info. What do you have your Wotobeus 120W car charger plugged into? I'm guessing it's a car cigarette lighter socket? What about if it was a battery box containing a LiFePO4 battery, ever tried it connected to something like that?

Yes, it's a car cigarette lighter socket.

 

[MAvic_South_Oz]

Sorry if this is irrelevant, I don't know how the M3 charger works, via the / a USB-c obviously, but I have found most of the DJI chargers require more volts than a resting 12v battery puts out.
Check whatever the charger voltage needs are, if more than normal resting battery output, the charger might just duty cycle like older chargers, and never have the power to do a full charge.
The older chargers need 13.1v, a resting 12v battery normally has 12.7v, so to get a 12v charger working with the older DJI chargers, I made up a step converter to take voltage to 13.8v and it works a charm for long range remote 4WD touring.
Probably not applicable to the M3 USB-c charger (?), but thought I'd mention it.

 

[Cammo]

Sorry if this is irrelevant, I don't know how the M3 charger works, via the / a USB-c obviously, but I have found most of the DJI chargers require more volts than a resting 12v battery puts out.
Check whatever the charger voltage needs are, if more than normal resting battery output, the charger might just duty cycle like older chargers, and never have the power to do a full charge.
The older chargers need 13.1v, a resting 12v battery normally has 12.7v, so to get a 12v charger working with the older DJI chargers, I made up a step converter to take voltage to 13.8v and it works a charm for long range remote 4WD touring.
Probably not applicable to the M3 USB-c charger (?), but thought I'd mention it.

Thanks for that info, really helpful and something to keep in mind. It seems to get to the point when the amount of variables make it hard to figure out where the problem lies. Is it the source of power (car cigarette lighter socket with car turned off, car cigarette lighter socket with car turned on, battery box containing LiFePO4 battery or something similar), the actual car charger (many different brands of type C PD car chargers) or the type C cable itself.

 

[MAvic_South_Oz]

Thanks for that info, really helpful and something to keep in mind. It seems to get to the point when the amount of variables make it hard to figure out where the problem lies. Is it the source of power (car cigarette lighter socket with car turned off, car cigarette lighter socket with car turned on, battery box containing LiFePO4 battery or something similar), the actual car charger (many different brands of type C PD car chargers) or the type C cable itself.

Mine (and others in various posts over the years) would charge fine when driving, motor running, and the alternator putting out 14,2 or so volts, but when turned off, after 20 mins or so it's be down to resting level and then the charger lights would come on / off, never did get a battery charged like that until the step up converter fix.
Lots of them on ebay, usually around US$30 - $40 or so, a heavy duty ciggy plug, and some suitable dual core, inline fuse, and some shrink tube for a neat finish.

Hope you can solve this simply, sounds like the cable type, USB type charging should be ok, but of there is a charger stage somewhere in there, it might just need more than the resting voltage of the LifePO.

 

[Kilrah]

Hopefully I've just got a dud car charger

It's likely not dud, it's just that USB-C wattage is only part of the story. USB-C PD supports various combinations of voltage and current i.e. profiles, and if your source doesn't support a profile that your destination can work with it won't run. E.g. if the device needs a 20V profile but your car charger doesn't have a circuit to boost the 12V input to that then it'll only offer profiles up to 12V and your device won't be able to power off of it.

Gotta check the requirements of the device being powered and choose a source that can supply that.

 

[bonzo]

Sorry if OT , just showing other options:

I use a Hantora $50 charger off ebay to charge all 3 of my M3 batts at the same time, plugged in to my EGO nexus power station which can do 3kw peak and 2kw continuous, pure sinewave. The batteries came with my EGO Z6 riding mower, four 56V 10Ah batteries for a total of 2.3 Kwh.
This power station can also operate using only 1 ego battery slotted in.

If less power is needed such as charging one battery at a time I take my smaller EGO Nexus PAD150 (150w) single battery inverter, modified square sinewave.

Less efficient, but I have so much capacity it doesn't matter, don't have to charge in the drone, and charging 3 batts at once is faster than single USB-PD charging. Pix below.

 

[Cammo]

Sorry if OT , just showing other options:

I use a Hantora $50 charger off ebay to charge all 3 of my M3 batts at the same time, plugged in to my EGO nexus power station which can do 3kw peak and 2kw continuous, pure sinewave. The batteries came with my EGO Z6 riding mower, four 56V 10Ah batteries for a total of 2.3 Kwh.
This power station can also operate using only 1 ego battery slotted in.

If less power is needed such as charging one battery at a time I take my smaller EGO Nexus PAD150 (150w) single battery inverter, modified square sinewave.

Less efficient, but I have so much capacity it doesn't matter, don't have to charge in the drone, and charging 3 batts at once is faster than single USB-PD charging. Pix below.
View attachment 143290View attachment 143291View attachment 143292

Great setup! Some good ideas there, thanks for the tips