Solar panel calculator 12v
Calculate what size solar panel and battery is required to provide constant 12v of power.
This is the most accurate calculator available on the internet
To view the calculator click on the location that is nearest to you. (it will open in a new tab)
What can you use this calculator for?
- Solar powered security cameras
- Internet hotspots
- Traffic management
- Communication devices
- Weather stations
- 40 km and 60 km speed limit zones such as schools and busy roads
What is so good about this calculator?
With this calculator you can see the battery charge level on a daily basis.
For optimum performance. You want to keep the battery charge level between 70% – 80% at dawn.
This calculator is interactive
- You can adjust the solar panel size to see what effect it will have on the battery charge level at dawn on a daily basis.
- You can adjust the battery size to see what effect it will have on the battery charge at dawn on a daily basis.
- You can adjust the power consumption to show what effect it has on the battery charge at dawn on a daily basis.
What are the limitations of this calculator?
This calculator needs to be configured for each location.
Each location has different weather patterns and different usable sunlight hours.
We use real solar data over many years collected by NREL.
There is no solar data available for some locations.
What variables do you use for the calculations?
- Location
- Solar panel tilt
- Solar panel azimuth (orientation towards the north)
- Daily solar production during the day to offset the power going into the batteries
- Daily usable sunlight hours based on the sun angle from the horizon.
- We assume an MPPT controller is used for high efficiency.
How we calculate
A brief summary is as follows:
- (Net day watts) = (Total watts produced by solar panel during the day) – (Total watts consumed during the day)
- (Sunset battery charge) = (Net day watts) + (Previous day dawn charge)
- (Dawn battery charge) = (Sunset battery charge) – (Total watts consumed during the night)
- Repeat step 1 for the next day
What are the features of the calculator
- Solar panel production based on the sun angle from the horizon.
- Minimum usable sunlight hours – (the sunlight hours during winter).
- Maximum usable sunlight hours – (the sunlight hours during summer).
- Constant watts for the load.
- Battery capacity in Wh.
- Solar panel size in watts.
- Total annual watts production of the solar panel.
- Daily watts production of the solar panel.
- Latitude and longitude location of the calculator.
- Minimum and maximum solar angle.
- Ideal solar angle.
- 1 day watt consumption.
- 3 day watt consumption.
- 5 day watt consumption.
- 7 day watt consumption.
- Average annual battery charge level % at dawn.
- Minimum annual battery charge level % at dawn.
- Maximum annual battery charge level % at dawn.
- Average summer battery charge level % at dawn.
- Average autumn battery charge level % at dawn.
- Average winter battery charge level % at dawn.
- Average spring battery charge level % at dawn.
- Daily battery charge level % at dawn.
Lithium & lead acid batteries (AGM)
This calculator is designed for lithium batteries. It can be used for AGM lead acid as well.
- When calculating lead acid batteries it is very important to keep the battery charge level % at dawn > 50%.
- Lead acid batteries can be fast charged as long as you do not over charge them