In short
- Read four moments: when charging starts, when the battery is full, when it starts to discharge, and where it ends at sunrise.
- A battery that is full by eleven is too small for the panels, or the house could use more of the midday sun.
- A battery that never reaches 100 % may have too few panels, or an inverter that stops charging early.
BSLBATT Monitor reads the battery’s BMS and draws its charge and power over the day. You do not need to stare at it every evening. One look at a typical sunny day and one at a grey day teaches more than any spreadsheet.
The four moments that matter
- Charging starts, usually an hour or two after sunrise, once the panels cover the house.
- The battery is full. The power line drops to almost nothing and the charge holds at 100 %.
- Discharge begins in the late afternoon, when the sun no longer covers the house.
- The morning level: where the charge stands at sunrise, just before the panels take over again.
Shapes worth recognising
Full by eleven, every sunny day. The battery fills early and the afternoon sun goes to the grid. Either the battery is small for the panels, or this is the time to run the washing machine, the water heater or the car.
Never reaching 100 %. Not enough panels for the battery, a cloudy season, or an inverter that stops charging before full. Compare with a clear summer day: if it does not fill then either, look at the charge settings.
Empty well before sunrise. The evening and the night use more than the battery holds. Moving one heavy evening load to midday often fixes it.
Grey days
A grey day shows the hill flattened: the battery climbs a little and gives it back in the evening. If it reaches the inverter’s cut-off at night, the house switches to the grid; that is normal in winter, not a fault.
Comparing over weeks
The free Cloud keeps up to three years of curves. Comparing the same week a year apart shows whether the battery still fills as it used to, a quiet way to follow its health.
Common questions
Where do I see the daily curve?
On the screen of the box for the present moment, on the local dashboard for today, and in the free Cloud for any day.
What morning level is normal?
It depends on your night consumption and the inverter’s cut-off. What matters is that it stays similar from one day to the next.
Does BSLBATT Monitor change charge settings?
No. It only reads the battery. Charge settings are changed on the inverter.
