Charge controllers prevent batteries from overcharging and over-discharging. Recharging batteries too often or discharging them excessively can harm them. By managing the battery voltage and current, a battery charge controller module can keep the battery safe for a long time.
Charge controllers protect the battery and allow it to deliver power while maintaining the efficiency of the charging system. Battery charge controller modules only work with DC loads connected to the battery. For AC loads, it is necessary to connect an inverter after the battery.
Charge controllers have a few key functions. They must protect the battery from overcharging, and they do this by controlling the charging voltage. They protect the battery from unwanted and deep discharges. As the battery voltage falls below a pre-programmed discharge value, the charge controller automatically disconnects the load. When the battery connects to a solar photovoltaic module, the charge controller prevents reverse current flow through the PV modules at night. The charge controller also provides information about the state of charge of the battery.
Various types of charge controllers are available in the market. Two of the most popular are the PWM or Pulse Width Modulation type and the MPPT or Maximum Power Point Tracking type. Although an MPPT type charge controller is more expensive than a PWM type, the former helps to boost the performance of solar arrays connected to the batteries. On the other hand, a PWM-type charge controller can extend the lifecycle of a battery bank at the expense of a lower performance from the solar panel. Typically, charge controllers exhibit a lifespan of about 15 years.
The XH-M60x family of battery charge controller modules is among the low-cost varieties offered by Chinese manufacturers. The most popular among them is the XH-M603. As the XH-M603 is not an overall charger, it is necessary to connect the battery to an external charger compatible to the battery.
The user can set optimal thresholds for initiating and terminating the battery charging cycle—making the charge controller a rather universal type, suitable for a wide range of batteries. Therefore, when the battery voltage falls below the set start value, the onboard relay starts routing the charging voltage from the charger to the battery. As soon as the battery voltage exceeds the stop value, the relay terminates the charging process.
XH-M603 battery charge controller module has a three-digit display on board for indicating the battery voltage. The display resolution is 0.1V. It accepts batteries with voltages between 12 and 24 V, Whereas it accepts input charging voltages between 10 and 30 VDC. The control precision is 0.1 V, while the DC voltage output tolerance is ±0.1 VDC. The overall dimensions of the module are 82 x 58 x 18 mm.
A small microcontroller controls the module, which has two voltage regulator chips onboard. There are a bunch of discrete components, including two micro-switches, a screw terminal block, an electromagnetic display, a three-digit Led display, and one red LED.
The charger connection to the module must maintain proper polarity. Likewise, the battery polarity is also important for the proper functioning of the module.