Tripling battery life span

[WithTheBirds]

Hi, the discussion is wayward since the lipo gets killed due to high discharge rate. This is just a starting point of discussion since current increases by about 25% between 100% charge to about 30% discharge. So people going to 20% are actually killing the battery instead of this post point. Also DJI uses very light 10c batteries which are highly stressed during end of flight. My 2 cents is to land at 30 or 35% and never do sports mode below 60% battery. You battery life is going through roof

Do LiPO cells get killed by high load- or- is the simple fact that higher loads reveal age and cycle related issues. Increased internal resistance in an older tired battery is obviously of greater consequence as the current demand increases.

 

[Manpreet Singh Bhatia]

What do you mean "current increases"? The AC demands what it needs. If anything, current capabilities would decrease at low SoC, not increase.

10C will probably be sufficient. It's C, not A, and C in the MA is 3500mAh so peak current is 35A.

Okay to make mathematics simple.. Drone taking some power to fly ...as lipo Voltage drops from 4.4v to 3.3v the current has to increase to reciprocate this loss. P =V x I. So you will appreciate the difference in peak vs bottom is 25%. I am sorry but being able to answer 100% to your vocabulary

 

[Manpreet Singh Bhatia]

Do LiPO cells get killed by high load- or- is the simple fact that higher loads reveal age and cycle related issues. Increased internal resistance in an older tired battery is obviously of greater consequence as the current demand increases.

Absolutely right lipo cell used by DJi are just on the border of weight vs current. They happily focused on weight. Lipo don't like high discharge rates then what is recommended or designed. I am personally trying to squeeze a 1500 mah, 20c into my MA1 battery. It has same weight as 2370mah of original lihv. Shorter flight but longer life. Not to mention 20usd spend on cells. Till now the bms is bricked and hope to solve soon

 

[TS_Thomas02]

In keeping with the observation that operational use generates more heat than charging, wouldn’t it seem that being a bit judicious with use of Sport Mode would yield the greatest benefit in heat mitigation and lifespan enhancement?

 

[WithTheBirds]

In keeping with the observation that operational use generates more heat than charging, wouldn’t it seem that being a bit judicious with use of Sport Mode would yield the greatest benefit in heat mitigation and lifespan enhancement?

You are assuming elevated temperature is the only or predominant contributor to reduced operational lifespan or performance. It isn’t. Quickest way to kill a LiION cell is to short the terminals, second is allow it to go below the min specified terminal voltage and leaving it sit there. Probably close third is keeping at elevated temperature while fully charged.

 

[Manpreet Singh Bhatia]

You are assuming elevated temperature is the only or predominant contributor to reduced operational lifespan or performance. It isn’t. Quickest way to kill a LiION cell is to short the terminals, second is allow it to go below the min specified terminal voltage and leaving it sit there. Probably close third is keeping at elevated temperature while fully charged.

I think the third is going higher than the recommended discharge rate.

 

[WithTheBirds]

I think the third is going higher than the recommended discharge rate.

Not with respect to our applications in any of the Mavic drones. Even a 20 min flight with the battery flown close to depletion equates to an average discharge rate of 3C, nothing for a good quality LiION cell. And don't forget that power management is a feature of the firmwares, you will see that propulsion is restricted in instances where measured battery parameters in flight suggest that limits are being approached (battery health is constantly monitored).

 

[BigAl07]

this is no way to encourage a good technical discourse. To say there is no evidence of charging cycles causing failure is probably inaccurate. I have heard of a few batteries puffing up during charge, especially on Mavic Air 1.

Most "early puffs" are from operator misuse. The Smart portion of the Smart batteries can only go so far protecting the batteries from misuse.

 

[DanMan32]

Not with respect to our applications in any of the Mavic drones. Even a 20 min flight with the battery flown close to depletion equates to an average discharge rate of 3C, nothing for a good quality LiION cell. And don't forget that power management is a feature of the firmwares, you will see that propulsion is restricted in instances where measured battery parameters in flight suggest that limits are being approached (battery health is constantly monitored).

I didn't think the AC would draw 10C, or 35A.

 

[Ems_pilot]

Nicely done, for sure a pleasant feeling to enhance things by your self ... but have you considered the Hanatora parallel charger, will add all (up to 4) batteries charged in parallel + RC, & also discharge to storage level.

Here --> https://www.amazon.com/dp/B08J7M1MPL/

Have one for the previous MA1 & works as advertised ... may be worth the money for the additional features & no need for any DIY.

*EDIT*

Copy & paste in the link above ... don't know why the "insert link" function goes to another place ..?

So, I fly a Mavic Pro and checked out the Hanatora charger. After digesting most of the posts i am still undecided. 1) Is the Mavic Pro battery considered hi-voltage lipo and able to handle the higher charge percentage? 2) If so will I get longer flight times, albeit less overall cycles? Thanks! (I am videoing our Christmas Light Show which runs 28 minutes and would like one continuous video if possible)

 

[slup]

...Mavic Pro and checked out the Hanatora charger.
...able to handle the higher charge percentage?
...longer flight times...less overall cycles?
...Christmas Light Show which runs 28 minutes and would like one continuous video

Hi there ... in this thread they have mostly debated the long term effects of charging less than 100%.

So don't really understand when you say "handle higher charge percentage" ... 100% is 100% & you will not be able to stuff in more... if you want the longest possible flight time with your present battery you charge to 100%.

And regarding longer flight time vs. less overall cycles in relation to your need of minimum 28min flight time is also a bit confusing ... if 28min is on the verge to be a too long flight with a battery charged to 100% you will not get any more by charging to 90% as suggested by the OP, he's referring to completely other thing's.

Further more the effects possibly gained according to the OP will in that case be long term ... not anything you can do as a preparation for a single flight.

The Hanatora charger (if it exists one for Mavic Pro) will not give you any more flight time ... the benefits with it is all 4 batteries charged in the same time as the original charger do 1 battery ... & features to treat your batteries correctly by auto charge or auto discharge to storage percentage.

 

[WithTheBirds]

I didn't think the AC would draw 10C, or 35A.

What’s your point?