Recording battery health?

[JoeSoap76]

Fairly new to this, but it seems clear that proper maintenance/care for the Intelligent Flight batteries is pretty crucial to their longevity. I've been doing some reading, but I'm not sure if I've got this right...

Aside from the warnings about storage and transport, in terms of health I think that I should keep a track of the cell voltage on each battery when fully charged. A battery of 4 cells is rated at 15.4v, so each cell should be 3.85v. Is that right? Is that how this works? (I'm very much not an electrical engineer)

If that is right, I'd expect that with age/use the charged voltage for each cell will start to drop off. So if one cell starts to fall away sharply that may indicate a fault or impending failure. And if they do all drop away at roughly similar rates, at what point would you usually start to think of a batter as being ready for retirement?

Also, the advice seems to be to fully charge/discharge these batteries every ~20 charges and to inspect them for signs of physical damage regularly/pre-flight.

Anything else I need to consider?

Thanks in advance

 

[JoeSoap76]

Okay, and after typing that whilst a battery charged, I've now gone in to the app and noticed it's at the max voltage (17.6v). But that aside... is the logic sound?

 

[DanMan32]

The fully charge discharge after every 20 cycles is suspect and likely outdated information.
Just don't abuse it like running down to zero % (though even that has a margin of safety) or keeping it charged at 100% for extended periods of time.
There are purists here that won't go past 30% or leave charged at 100% for more than 3 days. Personally I think that's overkill but harmless.