This 4 channel processor works great.
Can control many relays as more relay can be connected
to each channel. Easily programmable via PC. Connects
via old serial RS 232 port. If Ur laptop does not have such
get a USB-serial converter cable. They are cheap. Brand Tripp-lite works well, but any should do. Works particularly
well with a Tristar controller, but is also fine standalone.
Is the core of my E-system.
Pros: Programmable, multiple sense (voltage, current, temp)
Cons: Works slow with internal delay of ~ 1sec which make
on/off regulation of e.g. battery charging too cross.