Mavic2 Battery Mods

[beanbubba]

Here is the final weight after finishing out the battery mod. I could have removed the brass barrel connectors and saved 10 grams for each battery, but they were heavily soldered, then epoxied into place and I wasn't in the mood today to attempt that extrication. I just soldered the power cable directly to the barrel connectors.

 

[SkyNinja]

Here is the final weight after finishing out the battery mod. I could have removed the brass barrel connectors and saved 10 grams for each battery, but they were heavily soldered, then epoxied into place and I wasn't in the mood today to attempt that extrication. I just soldered the power cable directly to the barrel connectors.

View attachment 48676View attachment 48677

Is it possible to remove the rear, top and inside collision avoidance sensors?

 

[beanbubba]

Is it possible to remove the rear, top and inside collision avoidance sensors?

I have not been successful with this. At the moment the bird won't take off if the sensors or camera are removed. Lolo has some ideas but still a work in progress.

 

[beanbubba]

Bad news on test flights today. my AUW was 1602 grams and every 30 seconds or so the bird would go into auto landing with out any errors or other visible notifications. I lightened the load a couple hundred grams and situation normal. I did a half dozen flights of a minute or two and the motors were pretty hot for such a short flight at 1602 grams. The lighter load test flights did not exhibit the over heated motors. It appears DJI has programmed auto landing to happen if some telemetry reading is exceeded.

Here is one of the 1602 gram flights:

 

[SkyNinja]

Bad news on test flights today. my AUW was 1602 grams and every 30 seconds or so the bird would go into auto landing with out any errors or other visible notifications. I lightened the load a couple hundred grams and situation normal. I did a half dozen flights of a minute or two and the motors were pretty hot for such a short flight at 1602 grams. The lighter load test flights did not exhibit the over heated motors. It appears DJI has programmed auto landing to happen if some telemetry reading is exceeded.

Here is one of the 1602 gram flights:

What do you think the max AUW is 1580g? I think you need about 1.9mAh of power per gram of bird to fly the limit. What is your bird weight without batteries?

 

[beanbubba]

What do you think the max AUW is 1580g? I think you need about 7.75mAh of power per gram of bird to fly the limit. What is your bird weight without batteries?

Here is the base bird (that includes an amp in the battery shell), then the PT5600s, then TP4500s, then TP3500s.

I did many tests today with the TP4500 and TP3500 and zero issues and motor temps OK. I couldn't keep the PT5600s in the air after a dozen flight tests.
'
EDIT: I think I will take my TP4500 setup, then add weights to it until it fails. That's somewhere between 1322 and 1602 grams.

 

[SkyNinja]

Here is the base bird (that includes an amp in the battery shell), then the PT5600s, then TP4500s, then TP3500s.

I did many tests today with the TP4500 and TP3500 and zero issues and motor temps OK. I couldn't keep the PT5600s in the air after a dozen flight tests.
'
EDIT: I think I will take my TP4500 setup, then add weights to it until it fails. That's somewhere between 1322 and 1602 grams.

View attachment 48780

View attachment 48781

View attachment 48783

View attachment 48784

If you get a chance try fly with one 5600 and 4500 underneath the bird, that should give you a AWU of 1463g.

 

[beanbubba]

If you get a chance try fly with one 5600 and 4500 underneath the bird, that should give you a AWU of 1463g.

Good point, that would be easier.

 

[beanbubba]

I got 4 of these units. I hope they don't have the same balance issues like their bigger variants.

View attachment 48461

FOLLOWUP: of the 4 TP3500s I received, 1 of them errors out on the battery charger with a voltage error like what we saw with the 4500s. I will never purchase or recommend thunder power LiHv ever again. But note, when you do get a good battery, they are pretty rock solid and I like them a lot, but I can't support a 35% failure rate for brand new units and non existent customer service.

 

[beanbubba]

@SkyNinja what was your AUW on your longest flight on the m2 modified leaderboard?

 

[beanbubba]

If you get a chance try fly with one 5600 and 4500 underneath the bird, that should give you a AWU of 1463g.

I just had an AUW test flight of 1471 grams and it took a minute to kick in, but auto landing happened again.

I will keep testing, but narrowed the max between 1322 and 1471 grams.

 

[lolo780]

FOLLOWUP: of the 4 TP3500s I received, 1 of them errors out on the battery charger with a voltage error like what we saw with the 4500s. I will never purchase or recommend thunder power LiHv ever again. But note, when you do get a good battery, they are pretty rock solid and I like them a lot, but I can't support a 35% failure rate for brand new units and non existent customer service.

Is one cell out of balance?

 

[SkyNinja]

@SkyNinja what was your AUW on your longest flight on the m2 modified leaderboard?

My last leaderboard flight AUW was 1489. But Nate, Pablo and I have made leaderboard flights with AUW of around 1580g with no force landing issues. I believe I’m still on the original firmware. What firm where are you running?

 

[beanbubba]

My last leaderboard flight AUW was 1489. But Nate, Pablo and I have made leaderboard flights with AUW of around 1580g with no force landing issues. I believe I’m still on the original firmware. What firm where are you running?

View attachment 48885

 

[beanbubba]

Is one cell out of balance?

I deleted my prior post, I was mixing up threads. Yes, one cell is badly out of balance from the other 3 (as seen before).

 

[SkyNinja]

View attachment 48886

It’s strange that you’re getting that forced landing and others are not. I think I remember people getting this error with the Mavic air. I know @mlash did a lot of distance flying with the Mavic air, you may want to ask him.

 

[beanbubba]

It’s strange that you’re getting that forced landing and others are not. I think I remember people getting this error with the Mavic air. I know @mlash did a lot of distance flying with the Mavic air, you may want to ask him.

Was mlash's forced landing weight related, or just in general?

 

[SkyNinja]

Was mlash's forced landing weight related, or just in general?

No, is forced landing was not weight related, I just know he’s familiar with the Mavic air and If the Mavic air was having the same issues I figured he would know what the fix would be.

 

[mlash]

Was mlash's forced landing weight related, or just in general?

No... my forced landing was only because I ran out of battery.

 

[SkyNinja]

I just had an AUW test flight of 1471 grams and it took a minute to kick in, but auto landing happened again.

I will keep testing, but narrowed the max between 1322 and 1471 grams.

Bean, have you tried put the same amonunt of weight on your other M2 to see if you get the forced landing?