running an immersion heater from 2 PV scources -is it possible?

[skyewright]

If you're still on the look out for a big dumb battery charge controller. Both the xantrex c60 and morningstar tri star have diversion controller.

Would that work? I thought those controllers were designed for DC input sources?

AIUI the requirement here is for a charger that will take 240V AC from an immersun style inverter & turn it into DC that can be fed to a battery system or charge controller?

[iank]

Thanks

Yes, I am trying to get the water heated by an immersion heater using 2 different scources, one an existing grid tied 240v inverter that comes on when the power output exceeds 2kW, and another seperate off grid battery system that I would install myself.
ian

[nowty]

You could switch the immersion between your two systems but there would be little point as both systems would be generating at the same time unless you were to power the immersion from the off grid via the battery during darkness hours. That would work but heating water form the battery would be extremely wasteful and hard on the batteries.

I have a hot water tank with two immersions. I power the top one from the grid tie and the bottom one from the off grid, but only once the batteries are (nearly) full and even then ONLY with the excess PV, not from the battery as that is maintained full until I switch the house (low power circuits) onto it in the evening.

So on a good sunny day I am pumping 3kw+3kw = 6kw into the hot water tank and it heats up very rapidly.

[iank]

Thanks
That is roughly what i envisaged doing. My calculations were that to heat the hot water we use once the tank was up at temperature would need 1.4kWh per day.
I calculated that this could be done with with a 218 amph battery giving a 3 day hangover and 80% DoD, which did not seem that much to me. An 875 amph battery would give me 3  days supply with a 20% DoD. I have found second hand 2v traction batteries on eBay that were not too expensive.
Not being an electrician and new to all  this since retiring, I am a bit worried that I have somehow made a fundamental mistake somewhere.