Battery is vital for the Solar LED products. However , some of the customers don’t know how to calculate the battery requirement, which result in the wrong choose for the suitable products.
Keep on reading, hope this post will help you resolve your problem.
Firstly, you need to determine:
- how bright you need the system
- how long you need the light to run each night.
From this you can calculate the total watt hours you will need.
Watt-hours used each night = system wattage * running hours.
For example this system at full power is 20w, if you propose to run the light for 6 hours nightly, then the equation is simply: 20w x 6 = 120 watt-hours.
Secondly,the simplest means of calculating you battery requirements is divide
battery requirements = Watt-hours / battery voltage.
This will give you the amp hours you require.So we have 120/12 = 10 Ah’s each light required.
Thirdly, we can not discharge our batteries completely. Usually 50%-60% is the maximum discharge possible.
over discharge protect battery requirement = theory battery requirement * 2
So assuming a 50% discharge multiply your required amp-hours by 2. Which equals 20 Ah’s.
Forth,The next variable to consider is how many days of autonomy do you require in reserve for cloudy periods.
total battery requirement = over discharge protect battery requirement * reserve days
In a semi critical lighting system, 3 days of reserve should be sufficient. So the calculation becomes:20 x 3 = 60 Ah’s required.
Batteries are the most expensive component of a solar lighting system and are the limiting factor affecting how bright and how long you can run your solar light. So the above calculations need to be done correctly.
