To me battery capacity is more important than the extra solar.
Its more expensive too ... thus may not be an option for some folk.
I tend to leave cars a little low (70%)
My challenge in Summer is to have the cars below 50% - 'coz that's below the DRAG minimum on the dashboard.
My cars' charging flexes according to a combination of when I'm going to use them, and how sunny it is.
If I come home and the car is at 40% and I'm not going anywhere tomorrow / its sunny I definitely don't want the car to charge on Off Peak. (If I come home below 30% I will want to charge to at least 30% "soon", and if I come home below 20% I will charge to 20% "immediately" (i.e. using Peak rate if needs be)
If the car has 40% that's good for, say, 120 miles - that's a long unexpected trip for me
And the other car probably has more charge than that, so if I had to go somewhere unexpectedly I could take that (we prioritise charging the long-distance-preference-EV first / higher anyway, with the local/shopping EV typically maintained at lower SoC)
I’m not one of those who thinks about ROI
That £100 you saved is tax free. A higher rate tax payer is going to have to earn £200 to pay £100 of electricity bill ... There's ROI and then there's Man Maths
Also birdproof your panels. My big mistake… cost me another chunk for scaffolding a year later
Pisses me off that installers don't offer that ... surely its an upsell opportunity? ... even if they don't want to do it themselves there must be some mucker they could find locally and do a back-scratch with <sigh>
for trickle charge from solar - I have pod point charger - would I have to change it to zappi or something, or how do you deal with the PV output?
If a bit of API programming is within your ken? then you could do (based on my knowledge of PowerWall, I assume the rest are similar)
Battery > 95% AND PV generation >0 (or similar)
If so then charge car at X AMPs (X = based on PV Generation AMps less typical (or even "right now") household usage
If Battery falls 1% then reduce the AMPs by Y
If Battery rises by 1% then increase AMPs by Y (maybe when Battery > 97% then increase straight to 32AMPs)
If a cloud comes over you can choose not to react - and let Battery percent increase / decrease by 1% before you do anything ... or you could react (adjusting AMPs) according to what the Generation is each loop-iteration
Better to adjust amps frequently rather than stop./start charge (which will wear out contactors)
if I understand correctly, once car starts to pull 7 kw, I have about 1 hour of batteries, and then it is empty
Again, assuming some fettling using the API, you could increase Battery Reserve to whatever SoC is at the time when car charging starts - that will prevent discharge of battery. (Battery API may have a "Don't discharge" option too)
I financed them over ten years
For someone with savings this works better. The "saving" is then the return on investment - but its tax free, unlike regular savings - so likely to be well worthwhile converting Savings into PV-purchase - over 60's may get additional benefit too.