Good car charger?

[Tmoss1989]

ENeRgen Charger for Mavic Pro , has a usb Charger on it as well as two chargers for the batteries it rocks , check it out on Amazon it’s made by ENERGE——. QUOTE="Chirp, post: 473263, member: 26007"]Is there a dependable car charger that would be able to recharge a Mavic Pro battery in about 1.5 hours or so?

If there is a charger that would charge multiple batts in that 1.5 hours?

Thanks ![/QUOTE]

 

[Rorywquin]

I believe the DJI batteries have built in chargers and cell balancers.

Looking at my DJI "power supply", the main output (plug for charging the batteries) is shown as 13.2V and 3.79A and the usb ports are 5.0V and 2.0A.

After reading other threads on this topic I will be buying an inverter...so I can have 4 batteries on charge if need be.

 

[tictag]

It's actually the other way ... Mavic batteries require 13.1V - so the 12V is actually dc-dc converted up (boost) to 13.1V. Also, AFAIK, Mavic batteries do not have onboard cell balancing, otherwise there would be no need to report all three cell voltages in the GO4 app.

 

[Boss_Vyc]

I believe the DJI batteries have built in chargers and cell balancers. So any car "charger" is really only a transformer to take ~12V down to 5V (same as a USB).

Yes you're right. Bird batteries have incorporated PCB (power board protection) for balancing the charging , voltage and amps. You must provide only an stable 13.05 voltage and ampers between 4 and 6 amps per battery. The rest will do the PCB.
My charger can provide up to 12 amps. From there i use 3 resistors (2,2 ohm ;15 watts) for each battery. The battery will drain how much current he needs from the resistor. This is how can i charge 3 battery at the same time in around 70 minutes. If i charge only 2 the time will be less then 60 minutes and 1 less then 55 mn.

 

[Boss_Vyc]

It's actually the other way ... Mavic batteries require 13.1V - so the 12V is actually dc-dc converted up (boost) to 13.1V. Also, AFAIK, Mavic batteries do not have onboard cell balancing, otherwise there would be no need to report all three cell voltages in the GO4 app.

I can contradict you here. I dismounted a battery and measured it while it was on charging. the battery has built-in PCB and his balancing the charging current.
You can use an step up convertor up to 13.05 volts but you can't start the car engine because the input voltage wil go up too 14 volts and the convertor will be useless.
That's why you need step up/down convertor because the input voltage doesn't matter. The exit wil be precise.

 

[Rorywquin]

It's actually the other way ... Mavic batteries require 13.1V - so the 12V is actually dc-dc converted up (boost) to 13.1V. Also, AFAIK, Mavic batteries do not have onboard cell balancing, otherwise there would be no need to report all three cell voltages in the GO4 app.

My setup (Mavic air) is a transformer (in fact DJI have it marked as a power adaptor) that plugs directly to the battery therefore the balancing must be built int the battery pack. It is quite common to monitor the separate cells in a LIPO pack - DJI do it is so you can see if they are all in balance - if not, you need to do a full discharge and recharge and if that does not fix the problem your pack could be faulty and thus dangerous.

I've been using LIPO packs for 10+ years in RC aircraft but we have dumb batteries and smart chargers (with built in balancers). I believe that there are aftermarket fast chargers available for DJI batteries but fast charging will substantially reduce the life of your pack (as will recharging while it is hot straight after a flight). I believe that DJI have temperature sensors in the charge/balance circuit to prevent a hot pack being charged.

With my RC packs, I always have 3 per plane (1 flying, 1 cooling, 1 Charging) - we all use fast chargers but dumb packs are a lot cheaper -- the equivalent of my Mavic pack costs about £16 vs £69 for the Mavic.

 

[Boss_Vyc]

My setup (Mavic air) is a transformer (in fact DJI have it marked as a power adaptor) that plugs directly to the battery therefore the balancing must be built int the battery pack. It is quite common to monitor the separate cells in a LIPO pack - DJI do it is so you can see if they are all in balance - if not, you need to do a full discharge and recharge and if that does not fix the problem your pack could be faulty and thus dangerous.

I've been LIPO them for 10+ years in RC aircraft but we have dumb batteries and smart chargers (with built in balancers).

Correct. Only with an notification. The battery cell are LiHV not LiPo.
The balancing for each cell what you see in app is for an safety flight. If the difference between cell will be too big , you will get an error and the drone will landing or something like that.
Also you're right about temperature sensor inside the battery pack. Is there and when the cell goes warmer , the protection board will reduce the current for change. That's why the name for batteries is Smart.

 

[Rorywquin]

View attachment 38865


Correct. Only with an notification. The battery cell are LiHV not LiPo.
The balancing for each cell what you see in app is for an safety flight. If the difference between cell will be too big , you will get an error and the drone will landing or something like that.
Also you're right about temperature sensor inside the battery pack. Is there and when the cell goes warmer , the protection board will reduce the current for change. That's why the name for batteries is Smart.

So to rebalance the cells ...fully discharge & recharge? Powerbank adaptor would be good for this. I assume they will auto cutoff during discharge.

 

[Boss_Vyc]

Is normal to have different voltage after 33 minutes of flying. I use also in paralel 2 3000mah multistar batteries. If the difference is more then 0,3 - 0,5 volts then you got some problems. For discharging i use this stuff. 50w halogen lamp.
Always when i store the batteries for more then 2 days, i discharge them at 30-40% of capacity. The most important for having a longer lifetime.
With the power bank i mist wait too much for discharge.
With halogen lamp is very fast. From full charge i must wait around 25-30 minutes.

 

[Chirp]

Just for info, most cheap invterters use what's known as a 'modified sine wave' to invert DC to AC, these are fine for things like kettles but can cause problems with electronic gear. If an inverter is the way you're going, I would recommend getting a 'pure sine wave' inverter. These tend to be more expensive.

Where do you live? I actually have a spare Victron Energy 350W pure sine wave inverter, it's brand new, never been used but it has a UK socket.

Sorry for the long delay. Thanks so much for the information and the offer to sell the Victron. I don't have the electronics knowledge yet to really understand why a special inverter type is needed for these chargers. For now I'll make sure not to take on a job where more than 4 batteries is needed at a time because that's how many I have.

Besides I have a new project now that is taking most of my time. I purchased a previously owned DJI Inspire 1 v2 that came today. It is awesome in its own ways but it also makes me appreciate the Mavic Pro for what it does so well. I was thinking of selling the MP when the Inspire came but not now that I see what it's all involved here.
I'm gonna start a new thread about it in General Discussions tomorrow so so as not to hijack this one any further. I hope you all watch for it if it interests you... I will be comparing the Mavic Pro and the Inspire 1 V2 so I think it will be appropriate for this MP forum...