rachelfryer wrote:we wondered about a free standing trickle amorphous panel. The driveway is sadly north-facing so we won't get much but wondered if it's worth having a low charge going into the car.
You mention using an inverter for the water heater, so I'm guessing this is off-grid?
Unfortunately, there are only two ways to charge the Leaf: DC Quick Charge (400 volts) direct to the battery; and using the J1772 connector (120v/240v). The J1772 is basically a "smart plug", where the car talks to the power cord, and they negotiate how fast to charge. The minimum charging power the Leaf supports is 6 amps at 120 volts. If you could produce about 800 watts of solar power, then you could trickle-charge the Leaf with it. But I think you'd find that the cost of producing that much solar is higher than you're looking for.
As an example, a minimal solar system for that would be a 1kw to 1.5kw solar array, charging a DC battery bank, powering an inverter, trickle-charging the Leaf. (you need the battery, because the power produced by the solar panels will drop every time a cloud passes by).
For the solar array, I see Amazon has a "ECO-WORTHY 1KW 10pcs 100 Watts 12 Volts Solar Panel Module for Home Solar System" for $1020, or "ECO-WORTHY 1KW 24V Polycrystalline Off Grid Solar Kit: 10pcs 100W Poly Solar Panels+60A Charge Controller+1500W Pure Sine Wave Inverter+Solar Cable+MC4 Branch Connectors+Z Mounting Brackets" for $1568. I'm not sure if you can get 1kw of amorphous any cheaper than $1020. I've never heard of Eco-Worthy, but I would guess that anything mono- or poly-crystalline is going to work better than amorphous.
Four $80 6v CostCo/Trojan golf-cart batteries in series would give about 210 amp-hours at 24v, or 1.512 kw-hrs usable (limiting discharge to 70% full). That's enough to keep trickle-charging at 6 amps through 2.1 hours of clouds. Since this would require a custom EVSE, you could program the EVSE to wait until after sunrise, then also wait for the solar battery to complete bulk charge, then signal to the Leaf to start charging. Then charge until the solar battery string drops to 70% full, at which time you stop charging the Leaf; and repeat the next day, and so-on.
Trickle-charging at 720 watts is going to be very slow: it would add about 2.5 miles of range per hour of charging. If you get 10 hours of sun, you might get 25 miles of added range on a clear day. And it only works when the Leaf is parked at home. For off-grid homesteaders, that may be OK.