Battery monitor

JMC3 · Oct 15, 2021

I have the Mavic 2 and was wondering if there is a charger or monitor that reads exactly what the battery state is in digital numbers not just flashing lights?

eEridani · Oct 15, 2021

Battery Charge State -- this term is dangerous because it is very difficult to know with any precision. Just reading the cell voltage isn't enough. Generally speaking, you need to know how long the battery has been in 'rest', the details of the battery electrode and electrolyte characteristics, and volumes involved. They all factor into what is really going on inside the battery. And for cell charge comparison, you also need to know the cell temperatures along with the voltages.

You can make some general assumptions, but they'll not be accurate. The DJI flashing light mechanism is measuring the voltages and displaying a best guess of charge state - and why DJI says three LED's on means a state between X and Y based on knowledge of the battery characteristics. Also, if you press the button just after a flight then a few hours after a flight, you'll probably see a different LED pattern - the batteries tend to recover a bit, especially as temperatures change. A voltage reader will have this same variability.

But yeah - I sort of wish my Air 2 batteries had more LED's so I could know if it were within a 15% range and and not 30%.

JMC3 · Oct 15, 2021

when i flew RC sailplanes we used lipo batteries we also had a cell tester to determine with some accuracy if the battery was charged and if there was a cell going bad. I used a Tenergy 5-in-1 Battery Meter this is what i was wondering if there was one for drone batteries

eEridani · Oct 15, 2021

I don't know if there are good solutions out there that fit the need you are looking for; but -- if I want to know the battery state for my Air 2 - DJI provides a way to actually read the battery with some accuracy. Convoluted, but works really well:

Plug the battery into the drone; power up the controller and drone, open DJI Fly, wait for pairing, touch the battery icon.

A drop down opens with a reasonable display of capacity present. No flashing LED guessing needed.

It's not very convenient, but it works well. Touch the icon where it shows 81% ... and the flight times drop down.

ps: I believe the other flight apps show a similar display.

JMC3 · Oct 15, 2021

eEridani said:
I don't know if there are good solutions out there that fit the need you are looking for; but -- if I want to know the battery state for my Air 2 - DJI provides a way to actually read the battery with some accuracy. Convoluted, but works really well:

Plug the battery into the drone; power up the controller and drone, open DJI Fly, wait for pairing, touch the battery icon.

A drop down opens with a reasonable display of capacity present. No flashing LED guessing needed.

It's not very convenient, but it works well. Touch the icon where it shows 81% ... and the flight times drop down.
View attachment 136607

ps: I believe the other flight apps show a similar display.

I know about this but its kinda the dark ages of battery management epically at $140-150 per battery

Arnold LeVine · Oct 16, 2021

are you talking about disconnected from the drone? with the drone running, the app gives you a lot of info about the battery condition.

JMC3 · Oct 18, 2021

this video will show what im discussing

MAvic_South_Oz · Oct 18, 2021

..
There are a couple of possible solutions to this here, on a very similar thread today . . .

DJI Batteries Is there a device that will measure the battery Voltage

I have the DJI Mavic Air-2 and the Mini-2. Several of my Fixed Wing LIPO batteries Voltage can me measured by a small Led device that measures how much voltage is each battery, now I know which LIPO needs to be charged. Why doesn't DJI make a tool that has an LED read out to tell me...

mavicpilots.com

MS Coast · Oct 18, 2021

How about a cheap Volt/Ohm meter? They're handy to have around the house anyway.

$10.49 - https://smile.amazon.com/Etekcity-Multimeter-MSR-R500-Electronic-Multimeters/dp/B01N9QW620/

mixeysan · Nov 7, 2021

can make an autonomous clip to unlock the battery, as well as to display information about the battery, for example, as I described here on the forum => DJI Mavic - Аккумуляторные батареи - 4PDA