Solar Trailer math

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

watchdoc

Well-known member
Joined
Sep 19, 2021
Messages
157
Location
Greenville, NC
Hey guys, I've read lots of threads and different forums and I'm trying to scratch a solar itch I've got.

Goal: I want to be able to charge my Leaf while at work with a portable Solar Generator Trailer. I'm only at the office 3-4 hours a day (usually 12-3 or 4pm). I have an old small trailer I could repurpose. It's approx 4'x5'. I also already own a Handy PowerX portable inverter that I know for a fact will charge my Leaf using the stock EVSE.

So, I was thinking of buying one of these 200ah Lithium batteries off Amazon or Ebay and getting another Level 1 EVSE like the Zencar adjustable that goes down to 6 amp and the biggest single solar panel I can fit on the trailer to recharge the battery while I'm not at work. I realize a single panel (even a large one) wouldn't charge the Leaf indefinitely but if the battery would last 3-4 hours, then the solar panel could charge it back up all the time that I'm not at the office.
 
This used to be in the realm of "pipe dream" but with higher efficiency panels now available, I'm not so sure. What I am sure of is that 3-4 hours wouldn't be enough to add a lot of charge.
 
The majority of my charging is Level 1 at home albeit at 12amps. I figure I could add somewhere between 3-10 miles of range while I was at work per day. (depending on how many amps I can sustain charging) That's between 780-2600 miles per year.
 
I don't know what you pay per kWh for L2 charging in your area, nor what your residential rates are at. However, based on the residential rates I pay (which are relatively low), this project wouldn't have a reasonable pay back period.

One of the least expensive solutions would be a Bluetti AC200P for about $1600 USD, which has:

  • 2000W AC Pure Sine Wave Inverter (4,800W Surge)
  • 2,000Wh Capacity
  • LiFePO4 Battery with 3,500+ Life Cycles to 80%
  • 17 Outputs For Multiple Devices
  • 7 Ways to Recharge (AC/Solar/Car/Generator/Lead battery/Dual AC/AC+Solar)
  • 700W Max. Solar Input
  • 1200W Max. Fast Dual Charging (Solar + AC Adapter Simultaneously)

With that device, you could plug in the stock EVSE and charge at 120V@12A and transfer as much as 2 kWh to the LEAF from the built-in battery. Once the battery runs out, then the solar output alone won't be enough to sustain the L1 charging.

For a solar panel, you could purchase something similar to the PV350 (Bluetti panels are relatively pricey) to recharge the AC200P's pack when at home or at work.

However, you are looking at a total cost of at least $2200 USD (before taxes). It would take a lot of charging at public L2 EVSEs to make that investment worthwhile.
 
My residential rates are in fact low as well at just under .10 cents per kwh before taxes. This is more of a project that I would like to try out since I'm at least a year or two from being able to do a full residential solar install.
 
Will Prowse's YouTube channel is an excellent resource for all things solar and LiFePO4 battery related:

https://www.youtube.com/c/WillProwse

He also has an active community on his website forum.

This video is a good example of the quality of content he provides:

https://www.youtube.com/watch?v=e_o594CAdlo
 
Even more interesting would be to get the Bluetti 200MAX with the built in TT30 30 amp plug. I doubt the stock Nissan EVSE would would draw more than 12 amps but you could try to find an adjustable EVSE to take advantage of the extra amps. Then again, a lot of extra money for charging still slower than level 2.
 
That's just it - either device is too much for what you get in terms of both charging rate and capacity.

FWIW, my ZenCar portable EVSE is preconfigured for 120V@24A (2.88 kw) as one of the amperage settings. With that setting and an adapter cable, I can charge my LEAF via a TT30 receptacle when at RV parks.
 
I believe alozzy did as I did and ordered it directly from Zencar in China. If memory serves he got the 32a with a 14-50 plug and I got mine with a L14-30 plug so they limited the top current to 30a.
I built my TT-30 adapter as most I saw used 12g or less wire, which is only rated for 20a and I wanted to use the full 24a of a TT-30 and I believe alozzy did the same but again I'll let him answer. Either way for an adapter you want to make sure it says 10g or use at least 10g if making your own.
 
Yes, jjeff has it right - I ordered directly from ZenCar and specified a 14-50p. Jjeff was very helpful when I was trying to figure out the adapter cable details.

This post explains what I did, based on his advice: https://mynissanleaf.com/viewtopic.php?p=500259#p500259
 
watchdoc said:
I'm only at the office 3-4 hours a day (usually 12-3 or 4pm). I have an old small trailer I could repurpose. It's approx 4'x5'. I also already own a Handy PowerX portable inverter that I know for a fact will charge my Leaf using the stock EVSE.

I realize a single panel (even a large one) wouldn't charge the Leaf indefinitely but if the battery would last 3-4 hours, then the solar panel could charge it back up all the time that I'm not at the office.

Watchdoc - I do understand that "itch". I've actually designed and built two solar systems at my rural property (6500 watts) - and it was fun and rewarding - lots of pragmatic experience over the 8 years of service:
- In south TX, I get around 4-5 equivalent hours of energy - i.e. a 400 watt, 72 module panel ($$'s) will reap about 1.6 to 2 kWh a full day in good sun. And this requires no obstructions to the panel and tilted properly.
- Due to cloudy days, the overall "hours of energy" on a annual basis is a bit over 3 hours.
- Any type of battery energy storage will be very expensive per kWh as you will then need to have a reasonably good solar charge controller to last a decent time and stand up to outdoor exposure. Wiring, connectors and racking adds up quickly. The "round trip" efficiency of battery storage - with the added inefficient use of L1, low amperage charging must be considered to get a realistic miles/day from your system.

OTOH - DYI stuff is more about experimenting and learning for sure.
 
Marktm said:
watchdoc said:
I'm only at the office 3-4 hours a day (usually 12-3 or 4pm). I have an old small trailer I could repurpose. It's approx 4'x5'. I also already own a Handy PowerX portable inverter that I know for a fact will charge my Leaf using the stock EVSE.

I realize a single panel (even a large one) wouldn't charge the Leaf indefinitely but if the battery would last 3-4 hours, then the solar panel could charge it back up all the time that I'm not at the office.

Watchdoc - I do understand that "itch". I've actually designed and built two solar systems at my rural property (6500 watts) - and it was fun and rewarding - lots of pragmatic experience over the 8 years of service:
- In south TX, I get around 4-5 equivalent hours of energy - i.e. a 400 watt, 72 module panel ($$'s) will reap about 1.6 to 2 kWh a full day in good sun. And this requires no obstructions to the panel and tilted properly.
- Due to cloudy days, the overall "hours of energy" on a annual basis is a bit over 3 hours.
- Any type of battery energy storage will be very expensive per kWh as you will then need to have a reasonably good solar charge controller to last a decent time and stand up to outdoor exposure. Wiring, connectors and racking adds up quickly. The "round trip" efficiency of battery storage - with the added inefficient use of L1, low amperage charging must be considered to get a realistic miles/day from your system.

OTOH - DYI stuff is more about experimenting and learning for sure.

What led me down this road was experimenting charging my Leaf different ways. I have a Champion 3400 watt inverter generator and I was able to easily charge the Leaf with nothing more than a grounding plug. Worked perfectly and would handy in the event of a power outage. Next I purchased a Handy PowerX 1500/3000 Inverter for camping use mostly. I hooked it up to my travel trailer batteries (2 walmart deep cycle group 24's) and the Handy PowerX charged the Leaf just fine (120v@12amps) for about 15-20 minutes. I was worried about damaging the batteries so I stopped at that point. Next, I charged the Leaf with the Handy PowerX hooked up to my Ram truck while running. Worked perfectly. Just looking to experiment more and put some useful energy into my life.
 
Sure and I agree. I recently built an open shed behind my garage for my propane generator as a backup for hurricane use with a separate sub-panel. My ultimate plans are to install solar on my roof with whatever sensible V2X system becomes available. Meanwhile, I've been experimenting with direct solar charging for my Leaf at the rural installation.
 
Marktm said:
Sure and I agree. I recently built an open shed behind my garage for my propane generator as a backup for hurricane use with a separate sub-panel. My ultimate plans are to install solar on my roof with whatever sensible V2X system becomes available. Meanwhile, I've been experimenting with direct solar charging for my Leaf at the rural installation.

How do you direct solar charge?
 
Simple, but not easy. An arduino based control system with a variable amperage EVSE (OpenEVSE) that is buffered by a relatively small set of deep cycle batteries. Based on battery voltage and amperes, the solar energy is utilized to fullest extent via a 48 VDC based inverter with 240 VAC output to the EVSE. Mostly to prove that an off-grid solar array could effectively charge an EV with very little energy storage - basically a set of golf cart batteries. Just a DIY challenge that worked, but really only useful to maximize solar EV charging with very limited battery energy storage - off grid - my actual situation.
 
So it's still not batteryless?? How is that different than say using a Bluetti AC200 to level 1 charge the car at a specificed wattage and then having an equal wattage of solar panels charging the bluetti?

I assume you are aware that Enphase microinterters offer a "batteryless" setup that can supply AC power with just panels, microinverters, and an off grid batteryless control box.
 
I assume you are aware that Enphase microinterters offer a "batteryless" setup that can supply AC power with just panels, microinverters, and an off grid batteryless control box.

That's news to me. Do you have a link? I thought all the Enphase micro-inverters required a 240V input, either from the grid or perhaps battery backup, in order to operate.
 
watchdoc said:
So it's still not batteryless?? How is that different than say using a Bluetti AC200 to level 1 charge the car at a specificed wattage and then having an equal wattage of solar panels charging the bluetti?

Probably the main difference is that it was as an experiment with my existing solar system (3000 watts) and the fact I had 4 deep cycle FLAs in my golf cart. I Had no interest in a package - that likely did not even exist at that time! The other difference is the intent that the batteries only provided a buffer so that the varying solar inputs could be stabilized while the EV Level 2 charging changed amperes (OpenEVSE uses a RAPI control language that the arduino can use). Don't think any stand-alone system can do this.
 
Back
Top