Utilization of BuckBoost Transformer to Accellerate Level 1 Charging

Hello All,

Playing around here and decided to install a 13.3% boost transformer in line with my level 1 charge cord to see if there was an increase in charge rate. Normal line voltage here is about 115 so with the boost the LEAF sees 130V.

As you can see from leaf spy the charge rate is indeed increased with the higher line voltage, obviously there is no free lunch, and the current draw from the wall has increased accordingly.

Anyway I'm back on L2 now, but I was wondering if anyone else had done something like this for a small boost where L1 was the only option but the installed circuit supported a higher current draw.

There are 16A L-1 EVSEs available. One of those is what you want for a 20A 120 volt circuit.

I've thought of doing something similar for camping sites which have 30A 120v, but which have no 240v. Typical L1 EVSEs are limited to 12A (1.44kw). But you could use a 3kw 120/240v step-up transformer, plus a configurable 240v L2 EVSE to charge at 2.88kw.

I've taken my Leaf camping, and L1 works OK if you are camping for two or more nights.

page 10 of this report shows that for a 2011 Leaf the level 2 charging power is independent of voltage between 208 and 265VAC. i'm surprised if its different for level 1. maybe different model years are different.

https://gig.lbl.gov/sites/all/files/5b-halliwell-plugin-ev-charging.pdf

LeftieBiker said:

There are 16A L-1 EVSEs available. One of those is what you want for a 20A 120 volt circuit.

Click to expand...

We have on of those. We use it in on property down south that has a TT30 on it. We charge our smart car with it.

ripple4 said:

page 10 of this report shows that for a 2011 Leaf the level 2 charging power is independent of voltage between 208 and 265VAC. i'm surprised if its different for level 1. maybe different model years are different.

https://gig.lbl.gov/sites/all/files/5b-halliwell-plugin-ev-charging.pdf

Click to expand...

While that may be correct for an '11(and not sure about a '12) I know for a fact it's not correct for a '13 with the 27.5a charger. My '13 maxes out at 27.5a draw but I get varying degrees of kWh depending on my voltage, 242 volts at home, roughly 200 volts at work. Same on 120v, the more or less voltage around 120v the more or less kWh that goes into my battery. Now I'm not sure how the Leaf would handle say 150v? or something different than the approx 120v(IOW I'm not sure if the Leaf charger would work on any voltage between say 100v-260v or they have to be +/- around the standard 120v and 240v standards in N. America.
I do know that the '12 Leaf charger maxes out at 12a @ 120v and 16a @ 240.

A 16 amp evse running on 240v is plenty fast.
Is 240v unavailable?

LeafTaxi said:

I've thought of doing something similar for camping sites which have 30A 120v, but which have no 240v. Typical L1 EVSEs are limited to 12A (1.44kw). But you could use a 3kw 120/240v step-up transformer, plus a configurable 240v L2 EVSE to charge at 2.88kw.

I've taken my Leaf camping, and L1 works OK if you are camping for two or more nights.

Click to expand...

A 2013 LEAF will charge at a rate as much as 27A or more on a 120V circuit with the proper pilot signal so there is no need for a transformer with a proper EVSE. A 2011-12 LEAF is internally limited to 12A on 120V and this type of setup is pretty silly since you need a 20A dedicated circuit in which case it is better to convert the outlet to 20A 240V and use a 16A 240V EVSE.

EVDRIVER said:

A 2013 LEAF will charge at a rate as much as 27A or more on a 120V circuit with the proper pilot signal

Click to expand...

I didn't buy the J1772 spec from SAE, but the Wikipedia entry (https://en.wikipedia.org/wiki/SAE_J1772) implies that 120v charging is only defined up to 16A: "The J1772 standard defines two charging levels in 2017 revision in Section 5.1, Table 9... 120 volts 12A & 16A."

Even if that were the case, I would not be surprised if a 120v EVSE advertised 32A, a vehicle may consume it regardless of whether SAE planned for this scenario. I believe that Teslas can take 30A 120v.