The short answer is that you can charge a 6-volt battery with a 12-volt charger. So, what's the catch? The catch is that it can be dangerous to do so. On the other hand, you cannot charge a 12-volt battery with a 6-volt charger. There is no danger in trying to charge a 12v battery with a 6v charger. There is not enough. Ideally, the best solar panel to use to charge a six-volt battery is a six-volt solar panel. Because solar energy ebbs and flows throughout the day, the panel will deliver less than six volts. In short, a solar charge controller or a solar regulator limits the amount of energy from an array to its components, especially for Solar Battery Storage Systems. They also prevent the backflow of electricity when the sun. There are different types of solar regulators. They are PWM — Pulse With Modulation and MPPT or Maxim PowerPoint Tracking regulators, and they work differently. PWM Regulators— The keyword here is PULSE. You can charge a six-volt battery directly without a solar regulator, but you do so at significant risk. A solar regulator on the cheaper end is around $50. However, the regulator's cost is minimal.
