Help using excess solar to run a 300w immersion

[muttley9050]

Hi all. I'm currently doing another self build. I am fitting a 22l twin coil calorifier.
One coil for engine coolant and the other will eventually be a eberspacher.
I have 325w solar panel and would like the excess solar to automatically switch on the 300w immersion via a relay.
I was thinking of getting the 30amp renogy mppt but thought I would ask if anybody could help me with how I would wire this in and what components to use before I buy anything.
Thanks very much
James

 

[Derekoak]

So when your battery bank reaches a set voltage you want the solar switched to the immersion. Bumble solar do a variable voltage switch for less than 20 pounds that they claim would do that or you could get a similar looking thing cheaper from Alibaba shipped from China.bit would switch a power relay.

 

[1 Cup]

I've heard that but I think a temp settings are better as a 300w panle and a300w heater will only be good in the long summer months !. 20ltr of water 3 times a day every 2 days ,refilled once twice or 3 times 4 if showering . It could take a day to heat up to 60 degrees.
Senarriuo
Parked for 4 days.on a stand alone system 300watt element
1day cold just warm water legionnaires
second day run temp 65degrees. If turning on say at 2pm.. empty by 6 pm for washing up , shampoo. cold fill again. could be warm by 9pm maybeee. I think your need a 100amp battery. Or a bigger tank say 50ltr hot water tank
Mine runs off night heater. As hot waters needed in winter also.