Solar diverter that plays nice with battery storage?

[Val33]

New member here.

I have 6.5kw of solar and a Lux AC inverter connected to a stack of eight Pylontech batteries. I'm considering adding a solar diverter to catch the excess over 3.5kw that the Lux can't use in the peak months.

Which of the cheaper units work nicely with battery storage? I really don't want to be heating the hot water from the batteries!

Thanks

[Stinsy]

The easiest way to achieve this is to set the diverter to keep export at 100W (or something similar). That way the inverter and diverter don't fight each-other because the inverter tries to export zero right up to it's max charge rate.

I know the Solic doesn't have this feature and the immersun does have this feature. However I'd recommend an Eddi because not only does it have the feature but it is compatible with the Zappi BEV charging point so you can use your solar to charge a BEV from available solar if one is connected while the sun is shining.

[Val33]

Is the Immersion a setting or fixed in the design? I've read through the manual and I can see no mention of it.

The Eddie would be overkill for me. I have an EV but only granny charge on Octopus Go cheap rate. The house uses around 25Kwh a day so usually the only spare is what's left after the Lux.

[Stinsy]

It is in the "advanced settings" section of the manual IIRC...

[Stinsy]

Here you go, page 12, "Minimum Export":

[Val33]

Scrub that, I just realised that I was looking at 'Solarimmersion' not 'Immersun', naughty naming! The Immersun seems crazy expensive compared to the Solic or Solarimmersion units.

[Val33]

Thanks, yes I found it now. But both that and the Eddie seem way over priced for what is needed.

[greentangerine]

I have an Eddi now - the original Immersun went bang before I got my batteries - and I do exactly as commented above i.e. set the minimum export and even if the Eddi kicks in first after a transient house load, the battery inverter will then kick in because it sees that export and will take it, the result of which is that it'll take all it can and only then any surplus will go to the Eddi.

Works fine with my ME3000.

[Stan]

My Solic 200 has been installed for 4 months and I am delighted with it. It is supposed to prevent every Watt of export until the immersion reaches set temperature. So the power which I used to give away to the grid now heats my tank and that is really valuable in winter. There have been no issues and I cannot yet see why the battery should be one.

[nowty]

My Solic 200 has been installed for 4 months and I am delighted with it. It is supposed to prevent every Watt of export until the immersion reaches set temperature. So the power which I used to give away to the grid now heats my tank and that is really valuable in winter. There have been no issues and I cannot yet see why the battery should be one.

If the Solic takes every exported watt and transfers it to the hot water then that will be a problem for people with batteries as people with batteries generally want the battery full before diverting any heat to a hot water tank.

That is why some of us with Immersun's or Eddie's set a min export so the battery charger and the diverter to hot water can work in harmony. Otherwise they fight with each other until one wins or the whole system becomes unstable.

If there is a minimum export set, then the battery charger sees that as excess generated power and takes it, if there is still more excess power the diverter tries to keep the export to a set level until the battery charger has taken all the excess power. Once the batteries are full, the battery charger stops taking the excess power and the excess power will be available to the diverter for heating the hot water.

Sometimes a cheap and chearful diverter will work if its slower acting than the battery inverter.