My charging dock will only charge one battery at a time. If I put two batteries on it stops charging.

Just to verify, you mean charging hub, right? If yes, could you please provide us a short video of this case? I'll help to check. Thank you.

Have you been waiting a minute or two?
The hub stops charging the first battery after you put another one or two in.
It then figures out, which one to charge first, when to start the second,third one
And usually starts soon after again with charging

It charges in sequence on the same % level so if one battery is 70% and the other is 17% it will start charging the 17% first then the 70% simultaneously when the first battery recharge level is around the same then both will finish charging at around the same time. It’s actually more semi-simultaneous like the Mavic Advanced charging hub.

ACW Posted at 2017-10-25 06:13
It charges in sequence on the same % level so if one battery is 70% and the other is 17% it will start charging the 17% first then the 70% simultaneously when the first battery recharge level is around the same then both will finish charging at around the same time. It’s actually more semi-simultaneous like the Mavic Advanced charging hub.

That is why I bought a third battery.  You can't get one battery ahead on the charging, while you fly the others, since they wait for each other.  I guess the tray switches to cell balancing/trickle for all bays, when battery is full-ish, so the batteries have to arrive at that level together.

Gunship9 Posted at 2017-10-25 06:56
That is why I bought a third battery.  You can't get one battery ahead on the charging, while you fly the others, since they wait for each other.  I guess the tray switches to cell balancing/trickle for all bays, when battery is full-ish, so the batteries have to arrive at that level together.

This is why I bought a second multi charger. The power supply is limited to 50W and adding a 3rd battery really slows things down.

As other have already said though, be patient. After a few minutes you'll see that the battery that stopped charging will resume. I presume that the multi charger is trying to balance the limited wattage that it has across the batteries and when you plug a new one in it first tries to determine the need of that battery.

Not an ideal design for sure, but it does work.

Mine works well with two batteries. The one that gets first in, is also the first to finish.

heliman Posted at 2017-10-25 09:30
Mine works well with two batteries. The one that gets first in, is also the first to finish.

But not automaticly the first, that starts charging after you put a second one in, right?

TranceMist Posted at 2017-10-25 07:41
This is why I bought a second multi charger. The power supply is limited to 50W and adding a 3rd battery really slows things down.

As other have already said though, be patient. After a few minutes you'll see that the battery that stopped charging will resume. I presume that the multi charger is trying to balance the limited wattage that it has across the batteries and when you plug a new one in it first tries to determine the need of that battery.

Yep - from 15% to 100% full charge 1 battery takes 50 minutes, 2 = 55 minutes and 3 1 hour, 25 minutes according to the manual - which is fairly accurate.