KWH in VS KWH out

[offgridQLD]

MY off grid weekender house has around 1.8 - 2kwh AC Load over a 24hr period during the weekdays when we are not at the house and around a 4-6kwh load on the weekends when we are staying there.

I monitor the classic during the weekday using the remote app over the internet. What I'm noticing at the end of each weekday is the classic is has usually charged between 5.5 - 7.2kwh DC  into the battery to cover the AC load of 1.8- 2kwh.

Now I have read charging flooded lead acid battery's can be as low as 50% efficient when being charged from 90% SOC - 100% SOC . My system always works in this 90 - 100% perhaps even 95 - 100% range on a weekday. Due to small 1.8 - 2kwh -24hr weekday load and large 1330AH 48v battery bank . So combine that with 4kw of PV and lots of sun the battery's spend a lot of time on float, typically 9am - 10Am they are already on float.

Then there are Inefficiency's in the inverter converting DC- AC.  My inverter consumes 65w when on (I have sleep disabled) I have to leave it on 24/7 to power my modem, septic air pump & fridge. So just the inverter on load is an additional 1.5kwh DC load each 24hrs


So my weekday loads are 2kw AC being converted at (guessing) 85% inverter efficiency converting DC _AC. This takes me up to 2.3kwh DC + the 1.5kw DC load to Just run the inverter each day.


Giving me a total 24hr DC load on a weekday to around  3.8kwh DC. This is when we see up to 7kwh DC being fed from the Classic to cover that load. That brings my total efficacy to around 54%  when converting CD kwh in from the PV to DC kwh Out of my battery's.

Dose anyone have any numbers they can share . 24hr dc in vs dc out. Even a average over a week or month.Particularly with led acid.As its amazing how much is lost.

Kurt