Fu 08 There used to be a page on the Givenergy KB showing that the 4%-100% range available for normal operational use has a 15% lower threshold and 5% upper threshold built into the firmware which you can't see or access. Because of this, there's been a mess with the marketing of batteries, some being described as 80% Depth of Discharge, a few 90% and many 100% DoD. All of these have the unavailable manufacturer's end-point set in the firmware. The 100% DoD 9.6kWh batteries currently on offer are actually more like 12kWh and could be marketed as 12kWh/80% DoD or 9.6kWh/100% DoD; take your pick.
As a consequence, it doesn't matter who/how battery use is controlled, you will only ever be able to operate within the envelope allowed by the manufacturer's firmware, which protects their interests regarding warranty.
WRT slow charge/discharge; the inverter charge/discharge limits are set to protect the hardware and ensure that it lasts at least the length of the warranty. That said, we charge slowly and allow discharge at full rate. We charge slowly because we want to reduce solar clipping during the day. Over night in winter, the charge rate is set to whatever it needs to get the battery to the Charge to % by the end of the charge period. Sometimes this is 2kW+ but often it is <1kW. Slow is kinder all round, reducing losses due to heat, but not essential (IMO).
