Sometimes ago I talked with a vendor of solar power system integrator. We are discussing why our sizing were differ from them. Vendor’s proposal was bigger than us. One of interesting fact from their statement was that our sizing is minimum base and vendor’s recommendation was better to speed up the battery charging, thus increase reliability. Well, I thought it was reasonable at the moment!! but it brings me to confusion. My question by adding PV array, will speed up battery charging? is it technically true or marketing strategy by fooling customer?
Let’s see battery charging curve in figure 1.
Here the battery is lead acid type. We can see that duration of charging the battery is not depend on available power but depend on applied voltage. If the source is weak then the voltage will drop to prevent further charging process. If the source is abundant then the applied voltage is constant, but NOT increasing.
So, duration of battery charging is constant disregard available power.
So, don’t be fooled by vendor !!