Well we are tent campers and most of our sites don't have electricity.  So I'd like to be able to recharge my 2 P3S batteries during the weekend while camping - and I see that there is a car-charger offered-- but just wondering if it will drain my car battery if I don't have the car running?  Also how long it would take to charge the P3 battery.  And if there are different chargers offered or only the one I see by DJI?

Thanks for any comments!

Steve Schulte
Wednesday 27 April 2016

I have one of the car chargers sold on eBay for about $25 and it works just fine. But you need the engine running while it is charging as it draws about 4 or 5 amps. Unless you have a dual battery system you need to have the engine running. Mine takes about an hour to recharge. Just search for 'phantom car charger' on eBay.

Geebax Posted at 2016-4-27 18:23
I have one of the car chargers sold on eBay for about $25 and it works just fine. But you need the e ...

OK Great and I have been hearing that you really do need to have the car running while charging-- as you say!  I guess about an hour to charge from 25% or so?

Thanks for the fast reply!!

Steve
___________________________

don't think you need vehicle running all the time , but you may if you drive a shoe box

Probably not good for your car's battery. Certainly not good for your engine if you run the engine idle just to charge the batteries while stopped. You could maybe charge some batteries while on the drive up to location.

Or you could buy a portable generator.

I've also seen people wire up deep cycle battery banks in their trunk and inverters that allow them to charge a row of P3 batteries on the go, and they top off the deep cycle battery banks at home.

This one is the best as it also has USB ports to charge your tablet as well.
300W Dual 110V AC Outlets Power Inverter

If you want to go overkill, then get this.  Best for if you really want to insure you can charge multiple batteries.
3 AC Outlets 2000W/4600W Power Inverter

Car charger works fine. I up to now only used it while driving. Takes about one hour from approx. 20% to full charge.
If your car's battery is somewhat small and/or weak and you nevertheless charge two or three P3 batteries without the engine running, than you might risk being able to re-start your engine.
On the other hand, with a new and powerful battery (e.g. 60Ah) you should be able to charge at least 5 P3 batteries. This would keep the car's battery above half full, at least when it is not very cold outside.
But with a half full battery (lower voltage) the power (amperes) being consumed during engine start (work) increases with every unsuccessful ignition attempt. So this camping weekend could end not as expected..

I made a little thread for charger types and so on, does not look like many people use car chargers, but I am still considering one.. I can see it be useful when traveling or whatever....Nobody in that thread marked that they are suing a car charger, but reading above, my data is clearly incomplete.
GT

As I said back in post #2, I have and use one of the cheap eBay car chargers and it does the job quite well. I don't sit there with the engine idling, I use it to charge the batteries while I am travelling between locations. There is no need to go to the extent of buying inverters to power the DJI 'charger', as it is a huge waste of efficiency. You are converting 12 volts up to 120 VAC to put into a switch mode power supply to drop it back down to 17.5 VDC to feed the battery. The cumulative efficiency loss is high compared to a simple voltage doubling device.