How to stop your car charger from draining your house battery 

There's one other limitation of this method that I forgot to mention in the video. If your inverter is programmed to limit the power you can export to the grid (because of local regulations or the requirements of your supplier), then you also won't be able to send more than this amount to your car. I got my export limit increased for this reason.

I work for Octopus energy and I actually used this to better help/teach people about how this works in relation to our products so many thanks Quentin

I have the exact same issue. We have a 13.5kwh house battery, an eddy and a Zappy charger. We charge the car at night on a cheaper tariff but it still wants to draw power from the battery. The only way I can stop this is by setting a discharge limit on the battery, and/or, charging the house battery and the Ev on cheaper rate electricity and using that stored energy throughout the day. My install was completed to an excellent standard by an enthusiastic engineer but he says I cannot fit these CT clamps to my system due to space. I don't fully understand why but that's his reason. What I want is the panels to charge the house battery then release that power to the house as needed. I want my Zappy not to see the battery and just take power from the grid at low rate or take it from excess solar in the day but for us that doesn't seem possible. Apart from that I love what this install has done to change our energy costs.

Thank you for the excellent explanation. I had noticed the batteries were drained by the Zappy, and subsequently they were not topped up. (We use a Solis System with 2 x Invertors and 4 x Puredrive 5kw batteries). I was advised to stop the batteries from discharging during the tariff period, but this had no effect. So we have had an additional fusebox installed and the CT clamp moved from the solar network which seems to have worked, although the invertor is still reporting an import when the car is charging.

Nice work Quentin, I have exactly this set up. To simplify the wiring in the switchboard I simply fed the cables from the Zappi and the Edie back through the inverter CT, effectivally deleting the usage of both devices. this saves on installing a further distrubution board upstream of the house load distrubution board.

We have disconnected the Zappy CT Clamp from the Solar supply network as it did drain our batteries (4 x 5 KWH), but our house electricity network seemed to enable the Invertor to detect the Zappy. In the end you have to stop the batteries from discharging during the cheap tariff, and then backtrack and press the command - 'Allow' otherwise nothing happens. This also allows the batteries to be topped up. A simpler way of charging at any time from spare solar energy is to plug in a 13 amp charging lead - not as fast as the zappy but less goes wrong. And the Octopus Tariff is really good.

Thanks Quentin, I came to the same conclusion as you and fitted my Zappi outside of my Powerwall and solar set-up. I need to get an extra CT clamp installed on the solar output and the CT clamp on the house load only seems to work when the Powerwall is charging via the grid. I guess I have more to sort out! Thanks for the video.

Thanks Quentin, just what I was looking for! It was positioning of the CTs I couldn't get my head around! As long as Zappi feed from grid is before the consumer unit it should be good to go👍

Brilliantly explained Quentin - thanks so much for sharing your knowledge and experience. I am just at planning stage and your videos have been extremely helpful.

Very nerdy and interesting! Thanks for taking the time to explain!

Hi Quentin, getting my Zappi in today and wanted to show you my planned wiring to stop battery drain to see if you think its ok but dont know best way to get in touch, thanks Eddie

Fork off! Never heard it described like that before 😀

I have had solar panels since 2010, had a )(Chargemaster) charging point installed in 2020 and a battery system a year ago. So I have a two-inverter system. The car charger is powered as the first thing after the after the electricity meter and the effect is that charging my car never uses energy from. the battery. I have to admit it wasn't something I asked about when the battery was installed, but I am much relieved that it turned out that way. I sometimes need to force-charge the battery overnight (at cheap rates), especially during winter months, so I am very careful not to end up charging my car and the battery at the same time at night in case the load on the system gets too high.

Great explanation to what is a very common problem which afflicts different make Solar, battery, charger systems, which could be solved easily if the different manufacturers had a common / open comms protocol to integrate with each others products. I have a GivEnergy Hybrid Inverter, 9.5kW battery, 4kW array, Zappi & Eddi. Despite various timer & setting changes I cannot seem to stop our Zappi draining the house battery overnight when it's charging the car. GE have now added some battery pause charge / discharge time management settings in their App / portal but even these do not seem to prevent the battery from draining when the Zappi is charging the car at night. Something is overriding the battery settings & allowing the car to charge beyond our night time cheap rate tariff end time (04.30am) which then sucks all the energy out of the freshly charged battery. I have timers set on the car, the Zappi & now on the battery discharge but something allows the Zappi to continue charging the car beyond 04.30am & draining the battery. Maybe too many timers? More head scratching needed but I am determined to get to the bottom of this hopefully without an expensive system re-wire.

Hi Quentin, would love a video to see how your setup looks on your myenergi app. I have the exact same setup as you but still need to get an extra CT clamp so that the solar&DC batteries show up on the myenergi app. I assume the app can't tell the difference between power coming from solar panels and power coming from the DC batteries as it all comes from the same hybrid inverter is the only other problem I'm still pondering! Thanks again for you comprehensive and helpful videos 😊

Do you have a solution to octopus intelligent giving you a mid afternoon charge session when you plug in at 2 pm and when the car charges it drains the home battery. I have manually fied this by retiming my battery charge times but am looking for a neater solution which is automatic.

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