PV hot water system design questions.

[asdex]

Hi, I am planning to get a Morningstar MPPT 45 controller for my 6 x 320w (1920watts) panels and also use another PWM Morningstar 45 set in diversion mode to divert power to a 24vdc water heating element. I will have two batteries set up for 24 volts connected to the MPPT controller. The how water cylinder thermostat will operate a SSR to disconnect the diverter controller therefore the cylinder element and another SSR will connect the main 24 volt battery bank This setup is mainly to heat water and secondary to change the main battery bank. As the two batteries directly connected to the MPPT controller will have a small capacity compared with the PV output, they will nearly always be charged therefore the majority of power will heat the water which is my goal. Can anyone tell me what the voltage will be at the element and what current would I expect? Would it be 24 volts the majority of the time the sun is shining?
I think there is also a way to use a Midnite Classic for this but there is so much varied option and technical discussion on this it's difficult to follow.
Thanks,

[Mike90250]

Sounds like you have designed a system that is beyond me. Most of the time, a PWM and MPPT controller cannot share a PV array, they fight each other trying to "own" the array. But, the Midnight classic can be locked into a fixed voltage for MPPT and that might allow sharing . BUT, a 24V bank charges at nearly 29VDC, so that may throw the diversion controller off.

As to volts and amps at the heater element, I don't know the wattage, and cannot predict either.

[asdex]

Hi, thanks for that. I have attached a diagram which was supplied by Morningstar so this should work with the two controllers.
Cheers,