Energy Matters Forums

[markntime]

hi,iam new to solar although we have owned a totally off grid system for 3 years on a weekender. i have a small 4.2kw system with sma inverter with 16 panels. does anyone know of any issues with the sma inverters. we often we have 95% battery storage when we go to bed and 50% when we wake up. thats running fridge constantly and tv and 3 x 15watt light globes till 10.30pm. very frustrating.
we have 12 x 790ah gel batteries.
we had maintenance check up last week and advised all ok. is there a question i should be asking my solar electrician. they are saying more batteries.
thx
rgds
Mark

[Gordon-Loomberah]

Welcome to the Energy Matters Forum Mark

50% SOC in the morning suggests over 4kWh of energy use overnight, assuming the batteries have near their full capacity. If they have suffered significant capacity loss, then even 2kWh of overnight usage could bring them down to 50%SOC.

What brand are they?
Do you monitor energy usage with any sort of meter? If so, how much do you use overnight?
What is the battery voltage in the morning rested for an hour or more under no load before charging starts?
Have you checked individual cell voltages under load in the morning?
Have they been deeply discharged very often, or left at a low SOC very often?

If the battery really is on the way out, you probably should not add a new parallel battery, as it wont last very long.

[gemini2544]

I put timers on my Fridge & the Freezer to turn off from 11.00PM until 6.00am everynight. This cuts out the UN-needed usage. Fridges stay cold as everyone wet to bed, so food stays cold until the morning power clicks in.