Actual level of battery discharge

I have been surprised that the battery discharges to a low level (3%-0%) as I was under the impression that low levels of discharge has a negative impact on battery life. Because of my concern, I tried re-setting the battery reserve to 20% but it didn't seem to make any difference. I am beginning to think I have misunderstood this - maybe the 100% is not actually the full capacity of the battery? If I am right then hidden behind the apparent drops to low levels (3%-0%) the battery actually has a hidden reserve? If so I'd like to return the battery reserve level that I changed to 20% back to to what it was - but I can't remember what it was set at! Can anyone clarify the above and tell me what the battery reserve should be set at?
Maybe I should add that throughout this I am set to the Eco setting.
Hugh

GE Batteries are oversized which is why they offer warranty with 100% DOD. You might see 3% in the portal/app but it;s actually a lot higher. The BMS will protect the battery at the proper time.

cluelesscris that’s interesting. During the cold snap mine was at 0% for 5 days yet the inverter was still up and never wavered. So is that threshold like 10-15% I wonder?

Yesterday mine was at 4%, and I decided to do a full charge at midnight last night. It imported 3.8kw from grid according to the portal, at which point my 5.2kw battery reached 100% at exactly 0200hrs. It looks all wrong on the face of it as it was charging at over 2.5kwh, which would imply 5kw of draw from grid/charge at least, not 3.8. However I still have 7% left as 1700hrs !!

I was told to leave battery reserve at the recommended level, which is 4%.

Jumbo99 might have just answered my own question: my 5.2kwh battery has a Usable 4178wh, according to the label on it. I should have read that first!!