The feature of solar controller is to adjust the working voltage of solar panel intelligently, so that the solar panel always works at the maximum power point of v-a characteristic curve. The charging mode of ordinary PWM solar controller has three stages: strong charge, balanced charge and floating charge.
Strong charge means quick charge. When the battery voltage is low, it will charge the battery with large current and voltage. However, there is a maintenance point (overcharge protection) that stops charging when the battery terminal voltage is higher than this maintenance value.
2. Balanced Charging
After the end of strong charge, the battery will be normally placed for a period of time, so that the voltage will fall naturally, and then when entering the balanced charge. When the dc charge is finished, there may be a relatively low voltage at the end of a single battery, in order to make all the battery terminals voltage compliant, i.e., "balanced charging".
3. Floating Charging
Equilibrium after filling, the battery will be leave for a period of time, make its voltage across the natural, when falling to "maintain voltage", entered the floating condition, PWM (pulse-width modulation) both charging method, similar to "trickle charging, low battery voltage is charged on a bit, to the a shares, avoid the battery temperature rising, after conditioning pulse width to reduce battery charging current, make the battery service life is longer.