Victron's range of PWM and MPPT charge controllers are both widely used to charge batteries with solar power.
The PWM controller is in essence a switch that connects a solar array to the battery. The result is that the voltage of the array will be pulled down to near that of the battery.
A PWM controller is not a DC-DC transformer. The PWM controller is a switch which connects the solar panel to the battery. When the switch is closed, the panel and the battery will be at nearly the same voltage. Assuming a discharged battery the initial charge voltage will be around 13V, and assuming a voltage loss of 0.5 V over the cabling plus controller, the panel will be at V PWM = 13.5V.
The voltage will slowly increase with increasing state of charge of the battery. When the absorption voltage is reached the PWM controller will start to disconnect and reconnect the panel to prevent overcharge (hence the name: Pulse Width Modulated Controller).
More Product Features:
Load output with low battery voltage disconnect function.
Lighting control function, one timer only.
Two-digit seven-segment display for quick and easy setting of the load output functionality, including timer setting.
Three-stage battery charging (bulk, absorption, float), not programmable.
Load output protected against overload and short circuits.
Protected against reverse polarity connection of the solar array and/or battery.
