Draining Batteries Below 5%

[The Editor]

Ok fair enough but won't it still tell you that you have 10% remaining when the copter will no longer fly?Also Just beware that 1) every battery gets less cycles the deeper you cycle it and 2) the closer you go near actual 0% SOC for a multi-cell battery, the greater the chance that one of the cells may become "reversed" which does irreparable damage to that cell. BTW this is what can happen when you leave on your expensive 3 or 4 cell alkaline battery flash light until the light goes out. You open the flashlight only to find that one of the cells has "leaked" all over the inside. This is due to the fact that the weakest cell reached zero volts and then the other cells continue to discharge driving the weak cell into charging (i.e. The term "reversed"), generating hydrogen, bursting the safety vent and leaking electrolyte.

I think you are getting a bit confused with the percentage display versus voltage.
Voltage is absolute whereas percentage is simply perceived via a combination of voltage depletion and a fairly aggressive algorithm to take into account the deterioration of the cells over time.
The whole reason the fuel gauge needs recalibrating from time to time is precisely because the whole percentage thing IS inaccurate. The logic needs to be told what is 'zero' and what is 'Full'. That's it.
Personally, I don't fly and never have done using percentages. I only ever fly taking note of voltages but many people like the 'security' of seeing a percentage amount in the display. Additionally the 1st and 2nd stage triggers and RTH are based on this percentage sliding scale which is another reason (and probably the only one) to ensure your packs are calibrated.
The LVC on the Inspire packs is set so that all cells are monitored individually and is triggered on the lowest cell.
The rebound of the pack will bring the cells up to around 3.4v per cell after the load is removed which is absolutely fine.
Lipo damage will not normally occur until cells are dragged below around 2.9v

 

[Batteryman1952]

I agree you are right but my point is still related to an offset that would be created by using a secondary discharge with much lower resistive load like a light bulb to establish 0% SOC. You mention fuel gauge inaccuracies and all I suggest is that the fuel gauge be calibrated and zeroed under the proper discharge load. Imagine discharging your car battery to the point so that it won't start your car. As far as starting your car the battery is 0% SOC. But that same battery will still run your car's lights for an additional 8 hours. I would suggest that using car's lights to establish 0% SOC would create a major error for a car startability fuel gauge.

 

[SultanGris]

Difference is your car battery isn't smart and doesn't have a fuel gauge or shut off at a certain voltage. doesn't matter if you fly it or use a light bulb, the inspire battery shuts off at the same voltage no matter what discharge method is used to prevent damage.

 

[Batteryman1952]

Thanks for explaining!