Battery mod thread

Justinswidebody · Dec 3, 2019

DustinDunnill said:
Hey @Justinswidebody I knew I'd find you around here It's all clear to me now ?

Hey double d!! Let's get your mini modded so we can send it to another island and back!!!

DustinDunnill · Dec 3, 2019

Justinswidebody said:
Hey double d!! Let's get your mini modded so we can send it to another island and back!!!

That would be epic.

Dicky4480 · Dec 4, 2019

Longrange Tony said:
Looks good.

View attachment 85977

Why are you using someone else’s images?

Justinswidebody · Dec 8, 2019

I have now made a new bms mod for external batteries. I think it looks pretty good

. Some people are going to say the balance lead doesn't supply enough power..... I've done about five 40 min flights with it this way and no problems so far.

DustinDunnill · Dec 9, 2019

Justinswidebody said:
I have now made a new bms mod for external batteries. I think it looks pretty good . Some people are going to say the balance lead doesn't supply enough power..... I've done about five 40 min flights with it this way and no problems so far.

Cool man. How are you routing the batt leads to it? Through the door I mean... Or is that just a balance plug that's recessed further in the batter bay with BMS and your battery is still connected through a second Jst connector on top?

yamigos · Dec 9, 2019

Вut on bms firmware 300 i can change and reset battery too! Why not you said?

Justinswidebody · Dec 9, 2019

DustinDunnill said:
Cool man. How are you routing the batt leads to it? Through the door I mean... Or is that just a balance plug that's recessed further in the batter bay with BMS and your battery is still connected through a second Jst connector on top?

That's just a bms. The entire drone is powered by the balanced lead of the external battery. I would not use the jst connector at all. Battery just plugs into the but now lol.
Is easily removable, and undone.

DustinDunnill · Dec 9, 2019

Justinswidebody said:
That's just a bms. The entire drone is powered by the balanced lead of the external battery. I would not use the jst connector at all. Battery just plugs into the but now lol.
Is easily removable, and undone.

Got it. So the battery door stays open or are you planning to leave it off/cut a notch?

OregonEd · Dec 10, 2019

mavicn00b said:
Force land happens at 5% @ 3.3v.
Whats the "Cliff" voltage for LiIon batteries? DJI LiPo's would force-land on 10% and cliff voltage was about 3.2v.
My concern with this new quad is DJI's inexperience with this type of battery- dont know if they're cutting it close or being too conservative.

Full charge voltage is 4.14v or so. I tend to store them with 50% charge, then charge up and fly that day so they dont sit >4v for too long (preferably <12hrs). Once flown, cool to room them and charge back to storage level ready for next time.

My interest is given DJI was trying to get this <250g - if there was perhaps a higher capacity battery (official/aftermarket) for those who are already registered and dont care about the 250g limit.

They are definitely being conservative! I would put the cliff at 2.8V - 2.7V. Major transition begins close to 3.0V. (YMMV)

Justinswidebody · Dec 10, 2019

OregonEd said:
They are definitely being conservative! I would put the cliff at 2.8V - 2.7V. Major transition begins close to 3.0V. (YMMV)

At 2.8 volts the mini starts to loose the ability to go up and will only hover and start to decend

Justinswidebody · Dec 10, 2019

DustinDunnill said:
Got it. So the battery door stays open or are you planning to leave it off/cut a notch?

Like this

Marcuchinonis · Dec 10, 2019

yamigos said:
Вut on bms firmware 300 i can change and reset battery too! Why not you said?

Is this information true? Can I disassemble one stock battery to get one custom bms?

Justinswidebody · Dec 10, 2019

Best thing about this way, is you can overcharge it, use the bms and it tell you how much volts it has. Leaves you with 40min flight time minimum with right around 300grams all up weight. May not look the best, but it works the best.

I've gotten up to 47min with severe overcharging and the last 2 min are hovering without being able to make the mini acend anymore. Pretty much after 2.85volts the mini has a hard time lifting itself up. It can hover but not climb

Marcuchinonis · Dec 10, 2019

Justinswidebody said:
Like this

What cells are you using to get 37-40 min fly? Thanks

Justinswidebody · Dec 10, 2019

Marcuchinonis said:
Is this information true? Can I disassemble one stock battery to get one custom bms?

Yes this information is true as long as you haven't done a battery update

Justinswidebody · Dec 10, 2019

Marcuchinonis said:
What cells are you using to get 37-40 min fly? Thanks

Samsung 21700 50e 5000mah overcharged to 4.4volts per cell

Justinswidebody · Dec 10, 2019

I do not recommend overcharging (explosion could happen) You have been warned.

Marcuchinonis · Dec 10, 2019

Justinswidebody said:
Samsung 21700 50e 5000mah overcharged to 4.4volts per cell

I understand you chargue battery like a LIHV (4,4). Is it ok?

Marcuchinonis · Dec 10, 2019

Justinswidebody said:
Yes this information is true as long as you haven't done a battery update

Is there any way to check if the battery has been updated?

Justinswidebody · Dec 10, 2019

Marcuchinonis said:
I understand you chargue battery like a LIHV (4,4). Is it ok?

I haven't had a problem charging it to that at 1.5 amps.

I'm not sure on a way to know about the battery update. Does it show how many times you charged your battery in about section?