Fly More Battery advice

[pauljmuk]

Hi - sorry newbie and didn't find a defnitive answer on the search for this (or, at least, conflicting answers). What's the consensus on battery storage between flights for three batts on in the two way charger.

- Leave them plugged in to top them topped up at all times?
- Top up occasionally, but leave them in charger?
- let them drain?

I am talking about winter periods I suppose where flights may be a few weeks apart - perhaps longer.

What are your long term storage tips?

TIA

 

[Airbeaver]

The manual says to not leave them fully topped up for periods longer then 10 days and to store them somewhere around 40% - 70% ( I dont recall the exact percentages they recommend ) so no don't leave them plugged in or top them up when you plan on storing them for any length of time. They also will not drain on there own so you have to do it manually.

I do it by charging things around my house like my cell phone, wireless headphones etc. Just plug into your triple battery charger but note that it will only draw power from one battery at a time and not all 3 evenly.

As for the controller, I imagine its the same but I cant confirm.

 

[pauljmuk]

Yes - saw that in the manual - but of course begs the question of my old brain and memory!.

So imagine I leave them - the are ok on their own.. for a while. Presumably there is still natural drain though ? Not trying to be deliberately obstructive here, but.. What if they were left for 6 months? Do people have a plan for long term storage?

 

[old man mavic]

Hi - sorry newbie and didn't find a defnitive answer on the search for this (or, at least, conflicting answers). What's the consensus on battery storage between flights for three batts on in the two way charger.

- Leave them plugged in to top them topped up at all times?
- Top up occasionally, but leave them in charger?
- let them drain?

I am talking about winter periods I suppose where flights may be a few weeks apart - perhaps longer.

What are your long term storage tips?

TIA

just store them at 50 to 60% charge in the charge hub with them off, ie no lights showing and then once a week just give a quick press on the button and see what the state of charge is, and then when you are ready to fly again if you require all three just plug in the mains adapter ,and then the three batteries will charge one at a time ,if you only want to charge one battery then you can charge it in the drone ,and for two just remove one from the charging hub

 

[pauljmuk]

Thanks - i'm over thinking this I suppose.. but - for example, last year we had a lot of work done in the house and the last drone went into storage for half the year. Just worried about missing a window to check them - but I suppose that is what calendars are for..

 

[old man mavic]

Yes - saw that in the manual - but of course begs the question of my old brain and memory!.

So imagine I leave them - the are ok on their own.. for a while. Presumably there is still natural drain though ? Not trying to be deliberately obstructive here, but.. What if they were left for 6 months? Do people have a plan for long term storage?

for long term storage you should not let them get very low check them once a month and if needed bring them back to 50 to 60% and then check them a month later they will lose a small amount of charge over long periods the trick is to keep them somewhere in the middle range

 

[wjkrysak]

Good question. Always feel free to ask. Your learning may help others.
Yes, I agree with "old man mavic", you want to attend to your lipos and keep them in the modest range of 50-60%, when not in use. This improves longevity. Also on a side note: Always attend to your batteries while charging, for safety.
Heck, I have lipos' for my RC fixed wings that I have to keep an eye on, while stored or charging. A bloated battery is not a pretty, or safe, or inexpensive picture. Battery management is part of the hobby

 

[Filek]

But at the same time MM manual on page 22 says discharge 30% or lower
Go figure

 

[Christianpeso]

Yes - saw that in the manual - but of course begs the question of my old brain and memory!.

So imagine I leave them - the are ok on their own.. for a while. Presumably there is still natural drain though ? Not trying to be deliberately obstructive here, but.. What if they were left for 6 months? Do people have a plan for long term storage?

Depends what you mean by "natural drain". The batteries are not "intelligent batteries" in the sense that they can automatically discharge themselves after a certain time period. Heres a screenshot of the supposed manual for the Mini I got from the DJI forums:

 

[old man mavic]

unlike the batteries for other mavics, the MM batteries do not have a self discharge feature, so if you need to discharge them, that is why the hub has the ability to do so by allowing you to plug other devices such as a phone to discharge the batteries

 

[everBit]

Japanese version probably has self-discharge featue as it uses LiPoHV cells instead of Li-Ion in another versions

 

[old man mavic]

Japanese version probably has self-discharge featue as it uses LiPoHV cells instead of Li-Ion in another versions

i very much doubt it they would need to add that feature to each individual battery which would make them specific to the Japanese version ,but the are just a different type of cell in the same casing

 

[everBit]

it's not only casing difference they also have different firmware as LiPoHV should be charged to 4.40V instead of 4.2V, and discharged to 3.3V instead of 3.0V which is controlled by bms IC, so these version batteries are specific from the factory yet

self-discharge feature normally implemented at firmware level, so it's not difficult to put this option having in view it's need to be configured differently yet for specific cells

leaving LiPoHV cells without self-discharge mechanism would be degrade them fast enough so I'm 99% sure DJI has opted this feature, anyway it could be done through battery firmware updates later on if they forgot to do that)

 

[Drony_Drone]

This is what I’ve got direct from the MM manual that is on DJI website and collected all together as the info is in different places in the manual if it helps.

- [ ] Fully charge the battery at least once every three months to maintain battery health.
- [ ] Battery capacity is significantly reduced when flying in low temps (/5° to 5° C). It is recommended to hover the aircraft in place temporarily to heat the battery.
- [ ] The MM battery cannot discharge automatically. If the battery will not be used for more than 10 days, it is recommended to discharge the battery manually until the battery level is between 39% and 75%.
- [ ] Hibernation Mode: If the battery cell voltage is lower than 3.0 V, the battery enters Hibernation mode to prevent over-discharge. Charge the battery to wake it from hibernation.