cpthk
Posts: 2
Joined: Mon Feb 19, 2018 9:35 pm
Delivery Date: 20 Feb 2018

120V to 240V Transformer

Wed May 15, 2019 8:12 pm

I saw amazon sell the 120V to 240V transformer. Some brands only cost < $100. (like this) Even the more expensive ones are still under < $200. (like this) Could I use this to convert my house 120V to 240V for the leaf to get level 2 charging? Is there any down side to this? I prefer this since I don't need to hire a electrician to wire a 240V outlet, and no drilling to the house. It is also portable that I could move this anywhere I like. It is also cheaper. Thanks.
Last edited by cpthk on Wed May 15, 2019 8:34 pm, edited 1 time in total.

Deoc
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Re: 120V to 240V Transformer

Wed May 15, 2019 8:22 pm

Most 120v outlet can provide a maximum of 12 amp (1,440watts) no matter what you do after the outlet you won't be able to draw more power or you will trip the braker or burn the wire, some outlets let you draw 16 amp (1,920 watts) usually those in the kitchen area, no matter if you increase the voltage after you have a limit per outlet, you will need to get 220v from the panel to a new 220v outlet, there are other options but are against electric codes.

rmay635703
Posts: 498
Joined: Wed Jan 19, 2011 7:43 pm

Re: 120V to 240V Transformer

Wed May 15, 2019 8:46 pm

I thought the leaf (with an appropriate evse) could already draw up to the max amperage on 110vac?

Why would you need the losses of the step up transformer when the leaf can already draw up to 24 amps of 110vac?

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Nubo
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Location: Vallejo, CA

Re: 120V to 240V Transformer

Wed May 15, 2019 9:02 pm

cpthk wrote:I saw amazon sell the 120V to 240V transformer. Some brands only cost < $100. (like this) Even the more expensive ones are still under < $200. (like this) Could I use this to convert my house 120V to 240V for the leaf to get level 2 charging? Is there any down side to this? I prefer this since I don't need to hire a electrician to wire a 240V outlet, and no drilling to the house. It is also portable that I could move this anywhere I like. It is also cheaper. Thanks.


If your converter doubles the voltage it will also be halving the amperage. The total energy (Watts) available does not increase, in fact it goes down because of conversion losses in the transformer. When I was a kid I thought I could power the whole house from a 9V battery if I could make the right kind of transformer. Alas, it doesn't work that way. :(
I noticed you're still working with polymers.

smkettner
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Re: 120V to 240V Transformer

Thu May 16, 2019 8:23 am

No upside here. As said the transformer will not increase available power.

PULL THE WIRE
1 bar lost at 21,451 miles, 16 months.
2 bar lost at 35,339 miles, 25 months.
LEAF traded at 45,400 miles for a RAV4-EV
RAV4 traded in for I-Pace Dec 2018

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mwalsh
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Re: 120V to 240V Transformer

Thu May 16, 2019 8:27 am

Some of us, with wonderful instructions created by (IIRC) user Ingineer, built an adapter that allows you to plug into two 120v outlets on different circuits to obtain 240v for opportunity charging. I'll try to find the thread. Edit: Here you go:

viewtopic.php?t=4330
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Oilpan4
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Re: 120V to 240V Transformer

Thu May 16, 2019 9:48 am

You will be far better off doing it right.
Cut sheet rock, drill holes, pull wire, be happy.
It's just part of EV ownership.

Unless you were already wired up for big welders, plasma cutter, large air compressors and therefore already had easy access to multiple big 240v plugs in your driveway/ garage area.
2011 white SL leaf with 2014 batt.
Chargers: Panasonic brick moded for 240v, duosida 16a 240v and a 10kw setec portable CHAdeMO
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cpthk
Posts: 2
Joined: Mon Feb 19, 2018 9:35 pm
Delivery Date: 20 Feb 2018

Re: 120V to 240V Transformer

Thu May 16, 2019 7:46 pm

Thanks, everyone.

Is there a thing to plug from two 120V outlet and adds up the wattage? Of course I would connect from two outlets from different rooms that do not share the same circuit breaker.

Titanium48
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Location: Edmonton, AB

Re: 120V to 240V Transformer

Thu May 16, 2019 9:37 pm

It is possible, but they don't just need to be on different breakers, the breakers need to be on different legs of the split-phase AC service. Then you still have the problem that most branch circuits are 15 A and the cheap 240 V EVSEs try to feed your car 16A, which will likely trip breakers or possibly overheat wiring if the breakers fail to trip when they should.

Like others have said, you really need to find a way to get a 240 V circuit run to somewhere close to where you park your car. 40 or 50 A would be ideal for maximum charging rate, but 20 A will do if you are looking for the cheapest level 2 EVSE possible and you are OK with 40% slower charging (but still about 3x faster than level 1).

rmay635703
Posts: 498
Joined: Wed Jan 19, 2011 7:43 pm

Re: 120V to 240V Transformer

Thu May 16, 2019 11:11 pm

Just a note most every leaf will charge at least 16amps even on 110vac with a proper EVSE AND outlet.

20amp 120vac circuits are quite common and even the classic 30/50 amp. 110vac RV plugs aren’t unheard of

If he doesn’t care about the 1900 watt charge rate it is possible he could get a 20 amp 110vac outlet and evse.

It’s still better than 12 amps

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