Adapting for EV charger

ChrisAllenTQ2

Hi
I’ve recently started using wonder what over the winter and now we are coming into knee I wish to understand it better .
We have an EV that charges 12-30-5:30 in the off peak slot which is where the house batteries also charge with wonderwatt.
If for example wonderwatt calculates that we need 50% charge for the next day based on solar input and we start that charge session with say 60% battery and then the EV charger starts to deplete the battery when we hit the 50% will wonderwatt adapt and start charging to compensate? Another scenario would be if we were on 40% and wonderwatt wants to charge to 50% at say 20% charge rate at the start of the session will it adapt during the session to reach 50% at the end of the session at say 100%
Hope that makes sense ? Thanks

johalareewi

ChrisAllenTQ2
You don't really want the EV to be charging from the solar battery because you are losing a lot of electricity during the conversion stages which is costing you money. When the EV charger fires up, ideally, you want solar battery system discharge to be zero. WW has features which can help you do that and can help with the scenario you mentioned.

JayC

ChrisAllenTQ2 Does your supplier not control your EV charge? For example with Octopus IOG and WW there should never be (other than a few sync seconds) a time when you EV can drain your battery.
As for solar calculations, unless you are unable to sell/have a string green agenda, it makes little sense to use that function. My preference is to turn off Smart Charging: disregard the solar input algos, always max charge the battery overnight, prevent PV charging the battery during the peak of the day, thereby selling as much as possible to the grid back to the grid. Fastest way to ROI and the cheapest kWh, with much of the year being net positive (including SC).

KristianS

ChrisAllenTQ2
Some clarification of the current Import tariff you are on would be useful here, I think.
Also, bear in mind that an Import Tariff is not the same as an Export Tariff. By way of example, I am on Intelligent Octopus Go for Import and Outgoing Octopus for Export.
Refer to this help page for details >> Which export tariff can I combine with my import tariff?
While I have traditionally agreed with JayC and that is what I am doing today also, it is worth noting that the price per kWh is dropping for Outgoing Octopus to just 12p / kWh. When you consider your Import cost, and the round trip losses at ₁₀-20%, depending on chemistry, then this methodology starts to look less attractive going forward. Just something to consider

ChrisAllenTQ2

johalareewi thanks . I suppose if the inverter is in battery first which I imagine it would be then the battery won’t discharge to assist the load anyway ?

ChrisAllenTQ2

JayC I’m on octopus go tariff so don’t export at the moment . Although I’ve just upgraded to 91.5kwh of battery until today we only had 13kwh so as a family of 4 always use what we have imported during off peak and the amount we exported during the summer was very dependent on what solar we had during the day . This may change this year I guess . We have a Growatt inverter so not sure that can be controlled by octopus for a smart tariff ?

JoshuaSpendelow

JayC can you please tell me what settings you're using on ww? My home battery is set to charge whenever an off peak slot is active, however the home battery then sits idle at 100% and doesn't discharge to meet the demands of the house when the car isn't charging but instead draws from the grid.
Josh

JayC

ChrisAllenTQ2 91. Quite something! I’m sure many in this community would be interested to hear more on that spec and config. 3 phase?
I’ve been thinking about upgrading my Giv 13.5 AIO but seemed to be stuck with the single option of just adding another one, at the quoted 7k does not seem money wisely spent.

Octopus Intelligent Go only controls my EV. Wonder Watt monitor their API and manage my battery. I am not clear how that would manage at the scale you need.

johalareewi

ChrisAllenTQ2 I’m on octopus go tariff

Is that Octopus Go or Intelligent Octopus Go (IOG)?
From your first post it sounds like you are on IOG not OG.

ChrisAllenTQ2

JayC haha . Sorry meant 19.5 😂😂