MPPT Solar Controllers
Overview
Overview
MPPT Solar Controllers Overview
About MPPT Solar Controllers
About MPPT Solar Controllers
On a perfect day an MPPT barely beats a PWM. That is worth knowing before you spend the money, because it is not where the value sits.
An MPPT solar charge controller earns its keep on the days that are not perfect. A cold morning pushes panel voltage up, and an MPPT converts that surplus into charging current where a PWM would shed it as heat. Overcast light drops current but leaves voltage largely intact, which is exactly the condition MPPT tracking is built for. A long run from the roof down to the batteries costs volts along the way, and again the MPPT recovers what a PWM loses.
Add those up and the picture changes. It is not a fifteen percent gain on a bright afternoon. It is the difference between the batteries recovering and not recovering across three grey days in a row, which is when it actually matters.
It also unlocks options a PWM cannot. Running panels in series or using higher voltage panels lets you use lighter cable over a long caravan roof, because the current is lower for the same power.
Size it on output current rather than panel wattage, and give it somewhere with airflow. A 30A unit on a 12V system covers roughly 400W of panel, and one boxed into a tight cupboard will throttle back on heat well before it reaches that.




