Mavic Pro Battery Mod

kmokong · Aug 1, 2017

Whats is the polarity of pin 2-3 and 5-6

ScottJD · Aug 1, 2017

mlash said:
So I did a hover test today with 2 Zippy 1300mah batteries. I started with 96% on the mavic battery and and I hovered for 24:31 as you can see in the screenshot. When I uploaded the flight log to "Airdata UAV" it shows a much different story (see bottom pic) where it states that the flight was only 10:31 and that I landed with 62% battery left when I really landed with 13% battery and the flight time was 24:31.
Was the flight log just incomplete or is something else going on? Again this was only a hover test. I only took it up to around 3 feet.
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The logs for battery life I think are mostly based off of the protocol communication from the mavic battery. So it Depends on how you have the mod wired. If your soldered to the main board the power may be bypassing the mavic battery board completely so it doesn't get logged.
Other mods that went to the pins may have had the energy charging the mavic battery, and then going back out to the mavic so the whole discharging time and data was logged and reported.
It's hard to say, especially when mixing different battery types together and how the mavic battery board handles the power, if it charges with it, passes it through and stilll logs it, ignore it beucase the of some built in safety shutting off a path?
Or the battery just is not logging for some other reason, bad contact on the data pins from the mod to the pins being to thick?

It's also hard to say for sure without knowing how the data logs are gathered and mixed to create these reports. I'm sure if they are looking at battery data for the flight time then it might be wrong. They should look at another log for flight time, maybe compass, GPS, motor RPMs or something else to figure out total flight time.
Could also be a simple error on the log application from some update.

sprtbkrydr · Aug 1, 2017

kmokong said:
Whats is the polarity of pin 2-3 and 5-6

2/3-negative 5/6-positive

sprtbkrydr · Aug 1, 2017

I think it's great that these guys are making their own clips.

sprtbkrydr · Aug 1, 2017

Japtastic said:
Here is my data from the single top mounted 4000mah Multistar LIHV. More details a few pages back in this thread.

Airdata UAV - Flight Data Analysis for Drones

Don't look like you made it too far.

Japtastic · Aug 1, 2017

sprtbkrydr said:
Don't look like you made it too far.

That was hover only.

Just completed a flight with the same setup, fighting some fairly strong winds though as you can see and landed at 8% rather than 5%. I'm very happy with the result. Will add some more details of voltages etc when I get home. Will do some more testing in better weather

Here is the flight data with the same setup:

Airdata UAV - Flight Data Analysis for Drones

kmokong · Aug 1, 2017

Diy mavic pro batt mod adaptor

sprtbkrydr · Aug 1, 2017

kmokong said:
Diy mavic pro batt mod adaptor

Very nice job!

Ed209 · Aug 1, 2017

ScottJD said:
If your soldered to the main board the power may be bypassing the mavic battery board completely so it doesn't get logged.
Other mods that went to the pins may have had the energy charging the mavic battery, and then going back out to the mavic so the whole discharging time and data was logged and reported.

This isn't true. When you're running externals, the data being sent to the battery is only reading from the main DJI battery. Because you have external batteries, the main DJI battery drains at a slower rate. The remaining flight time should be pretty accurate assuming that all batteries are discharging at a similar rate. Sometimes, in certain cases, there is a little left in the main batteries and if a skilled pilot knows this, he can push the craft a little more knowing that there is some "reserve" left in the externals.

This has nothing to do with the way the external battery is connected. The DJI battery is coded and set to a mAh capacity and it will not account for any outside power, just the DJI battery. It can get thrown out of whack for various reasons and usually it can be reset by running it sans externals and draining down pretty low and then doing a full-charge.

@mlash You'd have to look at the logs in CsvView/Datcon to see what is really going on and if there was some sort of disconnect and to see the actual readings over time. It's hard to tell anything from AirData in this case.