What type of solar charge controller to purchase? First you need to know a little about their functionality and features but it’s also helpful to do a straightforward comparison of your options. Below we’ve put together a quick look at the pros and cons of both PWM Solar Charge Controllers and MPPT Solar Charge Controllers for you.
PWM Pros
PWM charge controller are built on a time tested technology . They have been used for years in PV systems and are well established.
PWM charge controllers are inexpensive , usually selling for less than $250.
PWM charge controllers are avaialble in sizes up to 60 amps.
PWM charge controllers are durable , most with passive heat sink style cooling.
PWM charge controllers are available in many sizes for a variety of applications
PWM Cons
The PV input nominal voltage must match battery bank nominal voltage if you’re going to use PWM.
We have not found a single controller sized over 60 amps DC
Many of the smaller and less expensive PWM charge controller units are not UL listed
Most small PWM charge controller units come without a wiring enclosure making it difficult to connect to conduit.
PWM charge controllers have limited capacity for system growth.
The Solar input nominal voltage must match the battery bank nominal voltage if you’re going to use PWM charge controller
Can’t be used on higher voltage grid connect type solar panels.
MPPT Pros
MPPT charge controllers offer a potential increase in charging efficiency up to 30 %.
These charge controllers also offer the potential ability to have array with higher input voltage than battery bank
You can MPPT Charge controllers get sizes up to about 150 amps DC.
MPPT offer flexibility for system growth
Ability to use higher voltage grid connect type solar panels.
MPPT Cons
MPPT charge controllers are expensive, costing on average about twice as much as a PWM controller
MPPT units are generally larger in physical size.
Sizing an appropriate PV array can be challenging without MPPT charge controller manufacturer guides.
Using an MPPT controller forces the PV array to be comprised of like photovoltaic modules in like strings.
As you can see in this brief list of pros and cons there is a lot to take into account when choosing a charge controller for your solar system and this can be very confusing if you are new to the renewable energy scene. don’t worry we are here to help if you need and over the next few days we will be adding additional post on how solar works and how charge controllers work
