Best battery discharge method?

WithTheBirds · Oct 31, 2018

crystal-pete said:
Yeah, and then WithThe Birds posted the link below - a much better and more comprehensive source:-

How to Prolong Lithium-based Batteries - Battery University

The author has excellent credentials.

I would have liked to have given you a better source for info- a lot of what is in that link is now out of date- tech has improved significantly. Another problem is that the numbers relate to discharge rates of 1C.

DanMan32 · Oct 31, 2018

No-one seems to have issues leaving their laptops fully charged all the time, even when they might not use it for some time, and not freak out when they run on battery until it goes to hibernate so why do we get uptight making full use of our drone batteries?

WithTheBirds · Oct 31, 2018

Cheech Wizard said:
I would say that current draw is a MAJOR factor as to flight time. Voltage = current (Amps) X resistance (Ohms)

An important factor absolutely.

What is most important is the reliability of the calculated usable Ah remaining.

Jackcutrone · Oct 31, 2018

mbsz53 said:
Every ten flights I run my batteries all the way to zero. Keep your drone running on the ground until it drains.

You never want to discharge a lipo battery below about 3V per cell. If you go to zero, I suspect you are lower than that.

WithTheBirds · Oct 31, 2018

DanMan32 said:
No-one seems to have issues leaving their laptops fully charged all the time, even when they might not use it for some time, and not freak out when they run on battery until it goes to hibernate so why do we get uptight making full use of our drone batteries?

I would have though its obvious.... A lost portion of a word document or half finished facebook post is likely to be of significantly less consequence than your Mavic or other flying toy being on the bottom of the ocean or causing personal injury or property damage.

Most people leave laptops connected to AC power for extended periods. The heat and high continuous SOC does significantly impact the performance and lifespan. It goes largely unnoticed however principally due to the fact that discharge rate in a laptop is significantly below 1C so increased cell IR is less of an issue.

WithTheBirds · Oct 31, 2018

Jackcutrone said:
You never want to discharge a lipo battery below about 3V per cell. If you go to zero, I suspect you are lower than that.

You suspect wrong.... LVC is set at 3V loaded.

You can go below 3V without destroying LiION cells, 2.7 is ok providing they are not allowed to remain there for an extended period.

DanMan32 · Oct 31, 2018

Besides by 0 he meant 0% which is not near the danger zone.
The later models will let you be below 0% when in flight (though it stays at showing 0%) until voltage can't sustain operation. Billy Kyle found that out the hard way.
At least his M2P gave him a chance.

WithTheBirds · Oct 31, 2018

DanMan32 said:
Besides by 0 he meant 0% which is not near the danger zone.
The later models will let you be below 0% when in flight (though it stays at showing 0%) until voltage can't sustain operation. Billy Kyle found that out the hard way.
At least his M2P gave him a chance.

Yes... There is a safety margin. 0% (depicted in the GO app) will leave the cells at about 3.2V no load after a short recovery period.