A solar cell requires a regulator (Pulse Width Modulation (PWM) or Maximum Power Point Tracking (MPPT) Controller), a bridge essentially, that converts the higher voltage DC from the cell to the lower voltage DC needed to charge batteries. The CTEK D250SE is a battery charger that can achieve the required voltage conversion.
It is possible also to buy a standalone solar regulator and in some cases you will find solar panels and blankets which come with a regulator bundled. In this case the low voltage output can be connected directly to the battery or elsewhere in the electrical system (under bonnet terminals? Yet to see an actual wiring diagram).
I might be oversimplifying, but as I understand it a MPPT controller is essentially a ‘smart’/variable charger while a PWM is a switch that must be selected to match a panel of specific voltage.
I’m still working through the merits of the D250SE versus reusing my existing solar regulator.
This blog post below might help. It’s not precisely the same model but I found it helpful…
The CTEK D250SA and Smartpass120 battery management system is the perfect solution for anyone who has big away from home power requirements.
allaroundoz.com.au