Eric Hanson wrote:....., you can discharge to zero, as indicated by the BMS, but technically there is about an extra 30 percent more you can get—you will just never get it back. But as a sort of best practice, it is recommended that you not discharge below 20% as per BMS, but that is not a hard and fast rule.
I think this is a very important point and therefore request confirmation that I am envisioning this properly. There is the "real" 0% and then there is the "BMS registered" 0%, which for safety/protective reasons are not the same, correct? The BMS 'determines' 0% to be when the battery is 'really' at 20% as a means to protect the battery (by shutting down) from over-discharge to the point of damage. Am I reading this correctly? My need for clarification is then on the statement "... it is recommended that you not discharge below 20% as per BMS": Are you saying to not charge below what the BMS is indicating to be 20% or the "real" 20% which the BMS is already pre-set to call "0%"? Does my question make sense?
Finally, just a point which may be relevant irrespective of battery type: Does a charger determine that the battery is at 100% by (a) zero amps of current flowing from charger to battery, (b) a certain voltage being reached and triggering shut-off/float stage, or (c) some other parameter that I'm not thinking of?? Maybe it's more complicated than this depending on battery chemistry and charger design?
Again, so glad to have seasoned experts here to help with our real-time conundrums. Just amazing to me the advancement in battery/solar technology since I first saw a panel in the 1970s and the idea was just getting its wings.