Mavic2 Battery Mods

SkyNinja · Nov 21, 2018

beanbubba said:
See the link of where you buy it please.

HobbyStar 8000mAh 15.2V, 4S HV 100C Hardcase LiPo Battery

beanbubba · Nov 21, 2018

I think I am narrowing the heavy auto land issue.

I am not an electrical engineer, but have enough basic knowledge to discuss this.

We all started heavy M2 flights in the heat of the summer and no issues reported. All the issues started trickling in as fall set in and got cooler temperatures everywhere. The last 2 days I did many heavy tests and most of them had toe warmer packets and were hot to the touch at takeoff. Today I did 4 heavy test flights of differing configurations but it was mild weather here and I didn't bother to unwrap the old warmer packs and foam insulation. All 4 fights auto landed in under a minute (in real forward flight, not hover test). I then repackaged a heavy set of batteries with warmer packs and foam insulation and the flight went without issue.

The M2 must have some current requirement that is affected with cooler batteries.

I am still testing, but this was pretty strong evidence I saw today. Anyone have theories on this??

PS - Lolo has been preaching warm batteries for years now and I finally see some proof he was always right

beanbubba · Nov 24, 2018

Question, I want to add a battery to my rig to power my iPad and RC. Should one use 1S or 2S for USB style power ?

mlash · Nov 24, 2018

beanbubba said:
Question, I want to add a battery to my rig to power my iPad and RC. Should one use 1S or 2S for USB style power ?

I would think a single cell. Or maybe use something like this and then any battery you want from 7-27V:
AOKoda QC3.0 LiPo Battery XT60 USB Phone Charger Discharger Adapter | eBay

I have one and I think they are very usefu. I use a xt60 to xt30 adapter since all my batteries have xt30'sl

beanbubba · Nov 30, 2018

Found this perfectly sized unit that has both AC and DC power plugs and warms up to 144F. Can easily go from house to car and keep warming while in the car.

https://www.amazon.com/gp/product/B01G7IL3BS/

SkyNinja · Nov 30, 2018

Well I finally crossed over to the Darkside, I mean the lite side. Switch from xt60s to xt30s[emoji38]

beanbubba · Nov 30, 2018

SkyNinja said:
Well I finally crossed over to the Darkside, I mean the lite side. Switch from xt60s to xt30s[emoji38]

View attachment 54651

You are a wise man obi wan

mlash · Dec 2, 2018

beanbubba said:
I think I am narrowing the heavy auto land issue.

I am not an electrical engineer, but have enough basic knowledge to discuss this.

We all started heavy M2 flights in the heat of the summer and no issues reported. All the issues started trickling in as fall set in and got cooler temperatures everywhere. The last 2 days I did many heavy tests and most of them had toe warmer packets and were hot to the touch at takeoff. Today I did 4 heavy test flights of differing configurations but it was mild weather here and I didn't bother to unwrap the old warmer packs and foam insulation. All 4 fights auto landed in under a minute (in real forward flight, not hover test). I then repackaged a heavy set of batteries with warmer packs and foam insulation and the flight went without issue.

The M2 must have some current requirement that is affected with cooler batteries.

I am still testing, but this was pretty strong evidence I saw today. Anyone have theories on this??

PS - Lolo has been preaching warm batteries for years now and I finally see some proof he was always right

I think you and Lolo are right about warm batteries! I've not seen this ever out here in the Desert but it was a little chili this morning. I think I'm going to start heating my batteries as well

Temp outside was 50f

beanbubba · Dec 2, 2018

mlash said:
I think you and Lolo are right about warm batteries! I've not seen this ever out here in the Desert but it was a little chili this morning. I think I'm going to start heating my batteries as well

Temp outside was 50f
View attachment 54912

Wow! I have never seen that message before and happy DJI is acknowledging it.

lolo780 · Dec 2, 2018

beanbubba said:
Wow! I have never seen that message before and happy DJI is acknowledging it.

I see that all the time, especially with Inspires as the batteries sit open to airflow.

I tested my M2P with full up (10m/s) and forward in sport mode for 50 seconds with no auto land triggered, but mine is all stock. Battery started at room temperature.

I'd have to check, but I did change some battery parameters before such as max power. Maybe someone with stock settings could try the same flight and see if auto landing is triggered?

mlash · Dec 5, 2018

SkyNinja said:
Yes it’s the one I was using on that flight. It comes in a hard case that you will have to remove.

Are you charging this battery to 4.35v per cell? Mine will be here tomorrow so hoping to test it out this weekend!

lolo780 · Dec 5, 2018

mlash said:
Are you charging this battery to 4.35v per cell? Mine will be here tomorrow so hoping to test it out this weekend!

Best to charge to 4.40v to match the stock battery.

SkyNinja · Dec 5, 2018

mlash said:
Are you charging this battery to 4.35v per cell? Mine will be here tomorrow so hoping to test it out this weekend!

I usually charge it up to you 4.40v and it ends up being about 4.38 by the time I get to my flight location get in the air.

mlash · Dec 5, 2018

lolo780 said:
Best to charge to 4.40v to match the stock battery.

SkyNinja said:
I usually charge it up to you 4.40v and it ends up being about 4.38 by the time I get to my flight location get in the air.

Yeah, that's what I was thinking too. Thumbswayup

mlash · Dec 6, 2018

Got my Hobbystar 8000mah HV battery today. Thanks @SkyNinja just about 80g lighter than 2x MS 4000's. Thumbswayup

lolo780 · Dec 6, 2018

mlash said:
Got my Hobbystar 8000mah HV battery today. Thanks @SkyNinja just about 80g lighter than 2x MS 4000's.

View attachment 55244
View attachment 55246

That's really good! Are you going to lighten them up at all? Interested to know how heavy the wrappers are.

mlash · Dec 6, 2018

lolo780 said:
That's really good! Are you going to lighten them up at all? Interested to know how heavy the wrappers are.

This is lightened up. I'm pretty happy with the 574g on the 8000. I was going to replace the 10g wire but I just cut it way down.
61g of weight removed

lolo780 · Dec 7, 2018

mlash said:
This is lightened up. I'm pretty happy with the 574g on the 8000. I was going to replace the 10g wire but I just cut it way down.
61g of weight removed
View attachment 55249

Is there any liner under the heat shrink, or just bare cells? You really want an air tight seal around the cells to keep heat in as the current draw is so low there's no internal heat generated. Thin foam directly on the cells covered in filament tape works fantastic.

I also shorten the balance leads and use an extension cable when charging.

SkyNinja · Dec 7, 2018

mlash said:
Got my Hobbystar 8000mah HV battery today. Thanks @SkyNinja just about 80g lighter than 2x MS 4000's.

View attachment 55244
View attachment 55246

Looks good, Time for you to go for the limit![emoji106]

mlash · Dec 7, 2018

lolo780 said:
Is there any liner under the heat shrink, or just bare cells? You really want an air tight seal around the cells to keep heat in as the current draw is so low there's no internal heat generated. Thin foam directly on the cells covered in filament tape works fantastic.

I also shorten the balance leads and use an extension cable when charging.

Yes, I've got some thin foam that I'm going to cover it with. My concern at this point is the "Auto Land." Once I do my first test flight and all goes well I will be more confident. I have bean following what you have bean saying about heating the batteries and I'm taking your advise for sure!