Is it possible to charge the mavic batteries from a portable power bank? For the road, on a hike etc. I tried the Anker PowerCore 20100 along with the battery to powerbank usb adapter and it doesn't charge at all.

The adapter that DJI sells is for charging a phone or other device using a charged Mavic battery.  If you plugged the smaller end of a standard USB cable in your Anker, then what you were doing was attempting to charge your power bank.  I don't know if there's a way to do what you want to do with the standard accessories, but it seems rather pointless because you'd be lucky to get much more than 1 charge from that powerbank.  (But I haven't done the math.)

Best portable solution I think would be to use a small sealed 12V battery and the car charger.

I've been using a Omni Charge 20 and the original mavic charger , but it's not an efficient solution too much energy is wasted, trying to figure how to connect the battery directly to the battery pack without the charger

lannes Posted at 2017-9-24 17:05
I've been using a Omni Charge 20 and the original mavic charger , but it's not an efficient solution too much energy is wasted, trying to figure how to connect the battery directly to the battery pack without the charger

That looks like an interesting little device.  I'd get one, but it's not $250 worth of interesting.

The specs on the Omni Charge 20 say its capacity is 73Wh.    The Mavic battery is 43.6 Wh.  So even if you were able to magically get 100% efficiency, you still couldn't even fully charge 2 Mavic batteries.  As big as that device appears to be, you'd be better off just carrying 2 extra Mavic batteries.

You're going to run into the same thing with any of these power banks.

Irate Retro Posted at 2017-9-24 17:23
That looks like an interesting little device.  I'd get one, but it's not $250 worth of interesting.

The specs on the Omni Charge 20 say its capacity is 73Wh.    The Mavic battery is 43.6 Wh.  So even if you were able to magically get 100% efficiency, you still couldn't even fully charge 2 Mavic batteries.  As big as that device appears to be, you'd be better off just carrying 2 extra Mavic batteries.

It works well with spark battery as you connect directly via the usb

lannes Posted at 2017-9-24 17:05
trying to figure how to connect the battery directly to the battery pack without the charger

If I remember correctly, that Omni charger has a DC output that you can precisely set to anywhere from 1-24V, right?  So you could set it to 13.8V and use the car charger which would get rid of inverter losses.  Or if you can figure out the pinout arrangement, set it to 13.1V and hook it directly to the battery.  Maybe buy one of those cheap chargers off ebay and cut the plug off of it to use.

Not that it's worth it for 1.6 charges, of course.

The Anker Powercore 20100 is a great powerbank for most purposes like phones, tablets etc. It is also reasonably priced. If it could work with the DJI batteries, I should get around 5 recharges (20100 mAh / 3830 mAh ) from the power bank. If this could work, it is pretty much equivalent to having 5 drone batteries. I don't have to call it a day when my 3 batteries are out of juice.

Hmm. The DJI mavic battery charger outputs 13V / 2A while the Anker powerbank output is 5V / 4.8A. So I suppose the voltage from the powerbank is too low even with a suitable adapter.

This could be the thing where you are looking for ...

https://advexure.com/store/drone ... ging-station-mavic/

rmf Posted at 2017-9-25 00:33
should get around 5 recharges (20100 mAh / 3830 mAh ) from the power bank

No, you're comparing apples and oranges there, because the voltages are different.  The math doesn't work like that.  You can only directly compare mAh when the voltages are the same.

The easiest way to calculate these things is to grab the watt-hours from the specifications rather than mAh.  The Anker Powercore 20100 is 74.37 Wh.  Mavic battery is 43.6 Wh.  So assuming a perfect world with no losses, you'd get _one_ full charge, and then be able to charge a second battery 70%.

Give it up with these "little" packs, guys.  There's no free lunch in physics.  You can hold your power bank in your hand and estimate how many charges you will get just by comparing the weight compared to the Mavic battery, since the chemistry is close enough.  When you came up with 5 recharges that should have indicated that something wasn't quite right.

If you want more charges you're going to have to carry something bigger and heavier.  There is no way around that.  A 12V gel battery as big and heavy as 1-2 red bricks would give you some decent charges, and has the advantage of being easily rechargeable via a small solar panel (given enough time).

If you are going to look for a third party charger, please be mindful on how it can affect the warranty of your DJI product.  Make sure that your charger is compatible with the specs of the Mavic.

Here is what I did! 7 Charges for under $250  

That's so cool! Thanks.

Hi guys! Do you think this combo will work?

vootshi Posted at 2018-2-14 05:11
Hi guys! Do you think this combo will work?

[view_image]

Did you try it? Worked?

Irate Retro knows his physics...  TBH if you're hiking, then the best and easiest option is to simply buy spare batteries.  This is why the combo options are good, so you get the extra batteries.  

Power packs are all designed to charge devices at 5v, whilst the DJI batteries need 13v.  So if you're absolutely positively needing to charge on the go without mains power, thn you need the DJI Car Charger (for 12v input) and maybe go for a lithium car jump starter like the Nocos that are small, have high capacity and have a 12v outlet.
Ian
https://no.co/products/power/jumpstarters

I know this discussion was for the Mavic battery, but wanted to pass along that with my Mavic Mini, the batteries charge just fine from from a "standard" USB micro cable.  I have changed both the batteries in the 2-way charging hub, and while installed in the Mini, from two different USB battery packs, and also in my car with a cigarette lighter to USB adapter.  One of the USB battery packs that I used is the Omni charge 20.  When I charged from the Omni Charge 20, I was using a USB output rather than the AC output and AC adapter.  Obviously the latter would be the only option if trying to charge with the Onmi Charge 20 a DJI battery that takes more than the 5 volts that USB normally provides.  You MAY also be able to use the selectable voltage DC output and roll your own cable.  You would be on your own with that one...