Battery mod thread

Kozmo1235 · May 11, 2020

this is a Potensic T35 Drone battery. Reason for leaving the boards, cause it's an already plug and play. I have 2 battery packs, they just take ages to charge.

Kozmo1235 · May 11, 2020

When I tested the positive and negative it ready about 8 volts, so I figured, why not just solder this battery on in parallel and see what happens.

and again please be kind, I only have a basic understanding here, I'm no rocket scientist.

Kozmo1235 · May 11, 2020

Now that I think of it, I'm guessing the additional Battery board is cutting down on the capacity...hmm

vadda · May 11, 2020

Sorry, it was not my intention to be rude, english is not firts language.
I think it's better to not mix 2 chemistry because they have also different discharge characteristic and you may damage the original battery
or , in the best case , do not use the full power of the original to run the motors but to recharge the external battery

Kozmo1235 · May 11, 2020

Well they both are Li-ion, one is just not a 18650 battery. Is that what you meant by different? you weren't being rude btw just saying, I only got a high school education here

Justinswidebody · May 11, 2020

You need to ditch the liion and go to lipo!
If you're going to stick to stock internal battery, then your best bet is to use liion on top as well... My best gains were from 21700 cells on top... Put me around the 45min mark.
Good luck! Let me know if I can help in any way..
Also, you don't need any additional bms boards...that's just adding weight... And mini can not handle extra weight in stock form...
Always make sure to get your center of gravity right or else it will put you in payload mode.

Kozmo1235 · May 11, 2020

keeps going into payload mode, so I'm assuming its cause of the center of gravity thing with the extra battery... \facepalm

Kozmo1235 · May 11, 2020

ok, so I decided to look on the internet for some things, and found some neat stuff. Tell me if anything of this would be worth buying to modify my MM.

Fenix Flashlight 21700 Rechargeable Li-Ion Battery (3.6V, 5000mAh)

Amazon.com: Plastic 18650 Battery Storage Case 2 Slots x 3.7V for 2x18650 Batteries Holder Box Container with ON/Off Switch, Set of 5, by Ltvystore: Home Audio & Theater

www.amazon.com

Amazon.com: M&A BD 2 Pack of Gold Series, 3000mAh, 20A, Rechargeable, IMREN, Replacement for Flat Top, 18650-Battery, for LED Flashlight with Free Storage Case: Home Audio & Theater

www.amazon.com

also, was wonder what would be the best battery to buy for the MM mod?

Justinswidebody · May 11, 2020

This is the cells I recommend, if sticking to liion

Samsung 50E 21700 5000mAh 9.8A Battery

Shop everything 18650! Rechargeable Lithium-ion 18650 Batteries, Chargers, Wraps – for custom battery packs and more! Popular brands for 20700, 21700, and 26650 battery sizes available.

www.imrbatteries.com

Kozmo1235 · May 11, 2020

will those work in this?

Amazon.com: Plastic 18650 Battery Storage Case 2 Slots x 3.7V for 2x18650 Batteries Holder Box Container with ON/Off Switch, Set of 5, by Ltvystore: Home Audio & Theater

www.amazon.com

Kozmo1235 · May 17, 2020

so I've got a battery with the DJI BMS still intact and working, with a hook-up soldered in so I can change out external battery. Now when I was doing my testing, I checked the battery voltage with just the 1 DJI battery, then check again after hooking up the extra battery, it increased in voltage just a little but that would be mean that the extra battery is working with the DJI battery right?

aeropic · May 17, 2020

Kozmo1235 said:
so I've got a battery with the DJI BMS still intact and working, with a hook-up soldered in so I can change out external battery. Now when I was doing my testing, I checked the battery voltage with just the 1 DJI battery, then check again after hooking up the extra battery, it increased in voltage just a little but that would be mean that the extra battery is working with the DJI battery right?

Yes for sure. It it was not working, either you would get a "not genuine batt" message or the motors would not rotate.

GfhTattoo · May 19, 2020

i got 2 battier need replacing on newest fw. hope 4 of thos Samsung battier work.
can i still use stock charger?

sorry new to drones low sleep. got the bms (battier managment systeam? ) on both . only 1 left working fly more pack.

dyslexic too.

Athiril · Jun 9, 2020

What’s the state of battery mods?

I was just thinking that a lightweight 450mah 2s lipo (which I have a few) would work well on mountains due to reduced weight and needing less thrust to stay in the air.

Does 3s work? I’ve seen the original Mavic pro run on 4s. That’d give more thrust at high altitude on a mountain without having to get some kind of custom prop

everBit · Jun 9, 2020

Athiril said:
What’s the state of battery mods?

There was info that DJI restricted or even blocked usage of batt mods with latest v500 firmware.
No way to enter Mini's engineering menu to allow flight below 3.17V.
And battery IC sets error flags and blocks charging if one try to replace the cells.

Bu if you are still at v200 or v300 then you are free to make and use the mods.

Athiril · Jun 9, 2020

everBit said:
There was info that DJI restricted or even blocked usage of batt mods with latest v500 firmware.
No way to enter Mini's engineering menu to allow flight below 3.17V.
And battery IC sets error flags and blocks charging if one try to replace the cells.

Bu if you are still at v200 or v300 then you are free to make and use the mods.

Guess I’ll go for a Fimi X8 or something, or whatever the next best non-DJI drone will be, at least it’ll have DNG raw ?

Source1234 · Jun 13, 2020

I'm just wondering since the board in the battery ⁹bricks when the battery inside is disconnected what if you can keep it on charge while replacing the lithium ion batteries will that keep enough power to keep from bricking the battery chip?

everBit · Jun 13, 2020

Source1234 said:
since the board in the battery ⁹bricks when the battery inside is disconnected

it's true only for v400 and v500 battery firmwares,
if battery and bird were not updated then cold-swapping thus with power interruption still works fine provided correct cells disconnection sequence is followed (see early discussions).

Source1234 said:
what if you can keep it on charge while replacing the lithium ion batteries

Keeping the battery on the charger while replacing the cells would definitely brick the board on all firmwares as this method not solve loosing cells volatges from IC's inputs (it's continiously monitoring each cell individually).

So for latest firmwares the work-around should be hot-swapping, where cells inputs are duplicated with same level voltages from another sources.

Any of proposed swapping methods not solving so called "delayed BMS bricking" issue already noticed by some Mini pilots with modded batteries after several succesive flights.
The mechanism of this issue still not clear and is under research.