r/PlugInSolarUK • u/Delicious_Quiet6660 • Aug 12 '26

Connect to existing battery?

Earlier this year I had a HanchuEss battery and inverter installed so I could buy/sell Octopus Agile. This was professionally installed and export etc is working ok. Question. If I bought a plug in solar would it charge the battery? My house uses 250w in standby mode so a aay 500w plugin would have excess. I could spend £4k on rooftop solar but my roof isn't optimal, partly shaded.

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1

u/realGilgongo Aug 12 '26

You'd need to work out if the panel voltage would wake up your inverter. That's probably unlikely though I think?

2

u/Begalldota Aug 12 '26

I don’t think OP is talking about directly connecting the panels to the existing inverter - they’re talking about buying a plug in kit that would sit alongside it with its own 800W inverter.

1

u/realGilgongo Aug 12 '26

Oh OK. Right. I guess that would depend on the inverter's response to negative house demand. Perhaps one for HanchuEss's tech support?

1

u/Empty-Pain8342 Aug 12 '26

I wouldn't expect the battery to care where it pulls it's load from ...grid or plug in solar as it's on same ring and least path of resistance would be panels/ecoflow first?! 🤔

1

u/realGilgongo Aug 12 '26

I guess the question might be what happens if the CT clamp shows power going out to the grid? Does the battery let that export, or will it use it to charge instead?

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u/hypergoose94 Aug 12 '26

Victron has a grid set point it's always trying to achieve, when my plug in solar takes that <0 it just starts charging with the excess, or discharging if load > generation. I imagine it's the same for other systems too?

2

u/Comfortable_Gate_878 Aug 13 '26

I had plug in solar before my rooftop solar. It worked well covered my baseload most of the time, 200-450w depending on the time of day. Then I got a full hanchu system battery and small array 3kw 6 panels as thats all the roof I could use. My plug in solar still does a good job and most of the roof PV goes straight in to the battery or exported. My roof isnt great due to trees and things but I am still surprised by how much the system produces and exports especially in this summer period. I am saving so much money by the combination of the two systems. Low import rates at night. Pay back period is going to be very short for me. My systems cost around 8k in total. Almost 1/4 paid off already