Barebones L1 extremely low current trickle charger?

Does anyone know if the LEAF will indeed charge at as low as 6A on 120V? I'm considering making an OpenEVSE-derived EVSE (for personal use, not planning a business case for it) that reports between 6A-8A so that I can use it with el cheapo extension cables and truly trickle charge my LEAF during the day at work off of some random exterior outlet, or when I go visit my parents (who knows what else they have on their garage's 120V outlets' circuit). The idea is to have an EVSE that's minimal and safe under pretty much any condition. Has anyone else done this? I know I'd only get something like 1 bar back after 3 hours or something insane like that, but in many of my use cases, that's perfectly fine.
I tried searching for these things before starting this thread, but I couldn't find much in the way of relevant info. Please feel free to point me in the right direction if you can, though!

The evseupgrade.com unit can be set as low as 6 amps at 120vac

Yeah, but it sounded like that wasn't a setting that could be saved. I might go that route, as I don't know if I have enough time to mess with making one, but I'd want that setting to be stored in some non-volatile way, rather than having to put a paperclip across some pins and clicking the button a number of times, as I understand the EVSEupgrade to work.

ishiyakazuo said:

Yeah, but it sounded like that wasn't a setting that could be saved. I might go that route, as I don't know if I have enough time to mess with making one, but I'd want that setting to be stored in some non-volatile way, rather than having to put a paperclip across some pins and clicking the button a number of times, as I understand the EVSEupgrade to work.

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I believe If you tell them at the time of order they are willing to flash the setting to make it persistent on your charger (They default to 12a for everyone but will set it to something else on request). You would still be able to change it to a higher setting manually but it would default to whatever they set it to during the upgrade.

If they don't chime in on this thread consider going to http://evseupgrade.com/index.php?main_page=contact_us" onclick="window.open(this.href);return false; and give them an email or phone call.

IIRC 6 amps is the lowest setting in the J1772 standard. And yes EVSEUpgrade definitely works at 6 amps 120 volts.
Have charged mine at the low rate using Go Power 2000 watt sine wave inverter.

I believe the setting holds until you unplug from the wall. Call EVSEUpgrade and tell them what you need.

If it can be programmed at time of purchase, that does indeed make it interesting. Thanks for that -- I'll keep it in mind!

It has been reported that the leaf pulls about 300 watts of "overhead" power while charging. That is listed as a factor in L2 charge rates being more efficient than L1 rates - the faster charge means one is wasting 300 watts for fewer hours.

Charging at 6 amps from 120 volts would give (at best) 720 watts. Subtracting the 300 watts would only
leave 420 watts to the battery. That would make a charge take a very long time.

Actually, when reading the title of this thread, my first thought was of a very low current DC charger, bypassing much of the powered charge system (keeping only the necessary safety equipment). Perhaps a set of protection diodes to prevent battery power egressing via the slow charge line, fuses to protect charge rate, and some means to protect against diode failure. Put the safety parts (not the fuses) inside the battery box, and have a low current DC charge feed. Now you could charge from a small solar array feeding DC direct to the battery. The roof of the car isn't that big, but if built as solar panels, it could provide 10 - 20 miles of range on a sunny day.

It would be more efficient to have a larger panel set over a parking spot feeding DC straight to the battery and keeping the sun off the car, but that would involve connecting and disconnecting.

The critical factor to make this work would be avoiding the need to have the fixed 300 watts powered up. Difficulties would include building the solar array into the car roof at economical cost, doing it in multiple sections to protect against output loss from partial shading, and the necessary safety factors.

There are some commercial 6A L1 EVSEs, look around you can probably get one cheap.

You can build an openEVSE and set it to 6A 120V for less than $200 and it can still double as a portable 240V level 2 to EVSE.

I have tried the EVSE that came with my 2012 Volt. It has a setting on it for 8 or 12 amps. The Leaf worked fine with either setting. You can pick up a 2011/2012 Chevy Volt EVSE on ebay for under $300 most of the time..

Huh, I thought the Volt's EVSE was set by the car... there's a switch or something on the unit itself?
8A was kind of what I was thinking, because of the overhead in the charging circuitry, etc. (and 8A through a long extension cord is very doable).

I used the Leaf L1 charger connected through two extension cords (75 feet total) until I got my L2 charger installed. The 25 foot cord is many years old, and the ends got warm while charging, but it worked fine outdoors for several weeks.

ishiyakazuo said:

Huh, I thought the Volt's EVSE was set by the car... there's a switch or something on the unit itself?
8A was kind of what I was thinking, because of the overhead in the charging circuitry, etc. (and 8A through a long extension cord is very doable).

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Yep - only on 2013-2015 models. The 2011-2012 models have the settings on the EVSE itself.