can a trickle charge damage my leaf battery?

Hi

We're looking into solar panels.

Our house solar will be pretty much spoken for as we were going to get an inverter for the hot water system already but 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.

However we were concerned that a low voltage input might damage the battery - does anyone know?

Thanks,

Rachel

rachelfryer said:

Hi

We're looking into solar panels.

Our house solar will be pretty much spoken for as we were going to get an inverter for the hot water system already but 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.

However we were concerned that a low voltage input might damage the battery - does anyone know?

Thanks,

Rachel

Click to expand...

Just don't even think about it. Grid tie all your solar and charge off the grid. You'll utilize 100% of what you produce.

To answer your specific question the single panel through an inverter to make 120VAC to 240VAC will charge the car. But as soon as it tries to draw a couple hundred watts as a test, the panel will collapse and nothing will draw. 2 panels directly facing the sun on a clear day with full power output won't even work.

You can make it work with a second storage system. Use the panel to charge storage, use storage to charge car. This is also how some DCQC stations work in places that don't support that power. They charge up a big internal battery at something "slow" like 10kw and then they can shoot it out at 100kW+. Or how hydrogen stations work, slowly storing the energy, and then releasing it quickly in bursts to fill up.

In your case, you use the grid for this. You push in your power to the grid, your meter spins backwards. You pull it out, it spins forwards. (Not 100% accurate today, but essentially with net metering). The grid is your biggest battery friend and you pay for the maintenance and upkeep monthly.

As someone who takes care of a few hundred batteries for UPS systems, you don't want that headache if you're asking this question.

rachelfryer said:

Hi

We're looking into solar panels.

Our house solar will be pretty much spoken for as we were going to get an inverter for the hot water system already but 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.

However we were concerned that a low voltage input might damage the battery - does anyone know?

Thanks,

Rachel

Click to expand...

To use the 120-volt Nissan charging unit (electric vehicle supply equipment or EVSE), you need a 15-ampere circuit because the onboard charger will draw 12 amperes continuous. It takes over 16 hours to charge if the battery is low. Therefore you need a minimum 2 kW inverter with sufficient battery storage and solar panel capacity to support that load. There is no way to safely charge the 360-volt traction battery directly (voltage ranges from about 300 when deeply charged to almost 400 when fully charged). You could trickle charge the little 12-volt battery with a solar panel and suitable charge controller, but there is no need because it is charged by the traction battery through the DC-DC converter when the car is either on (in ready to drive mode) or charging. The DC-DC converter a!so charges the 12-volt battery periodically when the car is parked.

rachelfryer said:

Hi

We're looking into solar panels.

Our house solar will be pretty much spoken for as we were going to get an inverter for the hot water system already but 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.

However we were concerned that a low voltage input might damage the battery - does anyone know?

Thanks,

Rachel

Click to expand...

You don't have access to gas? Electric water heating is very inefficient and if you have access to a gas line you should use that instead.

Or get a compressor water heater.

As for LEAF... perfectly fine to charge using the OEM 120v cord 'trickle charging'.
Or is the little panel just keeping the 12v battery charged? Get a controller for any panel over 7 watts.

rachelfryer said:

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.

Click to expand...

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.

solar panels will be charging at 12 volts each, and usually go into a bank of batteries.

you cannot charge the Leaf unless you used your 120 volt Level 1 charger. That requires a 15 amp, 120 volt circuit. No way do solar panels produce that. If you are off-grid, you cannot charge your leaf unless you have a good gas powered generator...