Keeping batteries topped up

[Ralph thompson]

Someone posted a question earlier about having a drone ready to fly. Which got me wondering if there is a solution to having batteries ready to use without having them fully charged all the time, probably a very bad thing to do. This must be a problem facing folks in SARS etc. Are there chargers that can be connected all the time and mentain say 80% max charge? And would this be good approach?

 

[msinger]

Which got me wondering if there is a solution to having batteries ready to use without having them fully charged all the time, probably a very bad thing to do.

It's a bad thing if you keep the same batteries topped up all of the time. A more ideal situation would be to have enough batteries where you could rotate them -- so they aren't all topped up all of the time.

 

[Ralph thompson]

I'm sure you're right, I wonder why its not a problem with electric car batteries, I understand you can plug in the car and it will keep it topped up to 90% or I hate to make the comparison, but I can plug in my Dyson vacuum cleaner and it stays fully charged. (it doesn't take great videos though

 

[MAvic_South_Oz]

, I wonder why its not a problem with electric car batteries,

It is, but as most are driven daily, it’s not quite as much of a problem.
With irregular driving patterns, it’s best to keep town use charges to the half to say 65% SOC level or they too will lose their efficiency over 4-5 years.
The sons Tesla X has around 75% range now after 5 or 6 years.
Same as a drone, if doing regular commutes, or a trip you can do the big charges without mid / long term damage.

 

[Cymru]

I used to do a rotation. Keep one at 100% and the other 3 on auto discharge and every 5 days or so i'd charge another one and let the full one discharge.

Its annoying but if you might suddenly need to fly with no notice at all there's not a lot of choice.

 

[karlblessing]

If you're flying daily, it's probably not a big deal especially if you keep rotating them.

But if you're only flying once a week, probably only top off the night before. If you keep topping them off without discharging then you're counteracting the self auto discharge to prevent battery swelling.

 

[Cymru]

Very little you can do if you need a standby battery that might be needed with zero notice.
All you can do is allow auto discharge and rotation.

 

[Ralph thompson]

If we could just charge to 90% and then cycle batteries, it would put less stress on the battery and with the M3 still have 20 mins flight which would be fine for my work. (Journalism)

 

[JoelP]

When I had an M1 I saw a few battery failures so became very concerned about storage. I used to fly my batteries down to 50-60% before storing them, but with my M3 I now let them naturally self discharge after 10 days to the 60% level. I wish DJI would let me reprogram this to 2 days. With 60% if I need to fly immediately with the M3 that is more than enough for most quick shots. That might not be the case for other drones with a shorter battery life.

 

[twickers14]

Have to say I rotate and try to have one on the MA2 (in the bag), one in the bag with it and one discharged/discharging in the battery bag. Probably not the best way but it does allow me to pick up and go when the weather is OK. I do check the two ready to goes before I leave home just to check they’re OK. If they not I have to admit I top them up-probably a no-no and I understand this is not the best way to manage them but it works for me.

 

[MAvic_South_Oz]

If we could just charge to 90% and then cycle batteries, it would put less stress on the battery and with the M3 still have 20 mins flight which would be fine for my work. (Journalism)

I wonder when the cell balancing takes place mainly ??
During the whole charging process, or near the end, some sort of 'overspill' to bring cells up to match ??

This is as important as storage SOC levels for longevity.

We see crash reports of people flying with batteries that have started discharges, and see 3 leds, think that's ok for this quick flight, and soon after take off their battery levels plummet, much like their aircraft sometimes too !!

It'd be good to know exactly how the balancing happens in the charge process.

With 60% if I need to fly immediately with the M3 that is more than enough for most quick shots.

It's ok to fly a battery down to 60% say, then same day fly for a quick shot, the cells are still balanced.
If it's been auto discharged previously to whatever level you may stop it on, or to the full 60% or so, then they are possibly going to give you the above problem some day, and I'm pretty sure flying with unbalanced cells is not good for the battery health mid to long term.

 

[Derek H]

I have a Mavic Pro and an Air2S and I charge up my batteries about every two months if they haven't been used. My son has a four year old Mavic Pro . His batteries hadn't been charged for at least 24 months and I expected them to be faulty but they charged up as normal. Was he lucky, or am I being unnecessarily careful.

 

[MAvic_South_Oz]

I have a Mavic Pro and an Air2S and I charge up my batteries about every two months if they haven't been used. My son has a four year old Mavic Pro . His batteries hadn't been charged for at least 24 months and I expected them to be faulty but they charged up as normal. Was he lucky, or am I being unnecessarily careful.

Luck of the draw Derek.

I too have left mine for many months, checking the SOC once of twice with a button press and generally none have ever dropped below 2 solid leds.

I don't think either of you are doing anything incorrectly, just different.

 

[JoelP]

I wonder when the cell balancing takes place mainly ??
During the whole charging process, or near the end, some sort of 'overspill' to bring cells up to match ??

This is as important as storage SOC levels for longevity.

We see crash reports of people flying with batteries that have started discharges, and see 3 leds, think that's ok for this quick flight, and soon after take off their battery levels plummet, much like their aircraft sometimes too !!

It'd be good to know exactly how the balancing happens in the charge process.



It's ok to fly a battery down to 60% say, then same day fly for a quick shot, the cells are still balanced.
If it's been auto discharged previously to whatever level you may stop it on, or to the full 60% or so, then they are possibly going to give you the above problem some day, and I'm pretty sure flying with unbalanced cells is not good for the battery health mid to long term.

I failed to mention that as my routine precheck I look at battery cell balance. Failing to do this with my M1 almost cost me that drone in 2 occasions. I think that the M3 batteries are more robust, but now that is a habit.

 

[Dbez1]

It would be nice, for those of us involved with SAR, if someone would invent a charger that automatically rotated one battery fully charged and the the others at something like 80 percent and 60 percent. Just wishful thinking ‍♂.

 

[Ponz]

Newbee here,

I keep hearing 'self discharge'

How do you allow a batter to self discharge. I have the Mini 2 fly more kit.

Ponz

 

[ssb73q]

Hi, Li-Pol batteries will self discharge, Li-Ion batteries don't. The Mini 2 has Li-Pol batteries, but the Mini 2 can also use the Mini 1 Li-Ion batteries that don't quickly discharge in time. I keep a couple of my Mini 1 batteries fully charged so I can get the Mini 2 up in the air quickly. The Mini 2 isn't the best drone for SAR, but it's nice to know I can get a drone up in the air quickly if needed.

Regards,
Richard

 

[Ponz]

Hi, Li-Pol batteries will self discharge, Li-Ion batteries don't. The Mini 2 has Li-Pol batteries, but the Mini 2 can also use the Mini 1 Li-Ion batteries that don't quickly discharge in time. I keep a couple of my Mini 1 batteries fully charged so I can get the Mini 2 up in the air quickly. The Mini 2 isn't the best drone for SAR, but it's nice to know I can get a drone up in the air quickly if needed.

Regards,
Richard

SAR?

 

[Jamesz]

I use a 3- way parallel charger (with inverter for the vehicle) for the Mavic pro used for SAR (search and rescue). During the planning stage and driving to the event, it brings all 3 drone batteries, the controller and phone /tablet up to full balanced charge from their standby 60% storage charge. I tried cycling batteries, but this has worked out far better. Just don't use a serial OEM charger.

 

[msinger]

How do you allow a batter to self discharge

Per the Mini 2 manual: