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Q: 120V emergency cord

Posted: Thu Jun 24, 2010 4:54 am
by IceRaven
1- Since typical electric outlets usually have 2 connections for 2 plugs (dont laugh if its nonsense) , could there be an alternate 120V emergency cord model with dual cords ending with 2 plugs, so that you can connect both cables? Would that have the potential to channel more electricity? Would the Leaf charger be able to channel this dual 120V input to reduce charging time?

2- Is there any way the 120v recharge time can be reduced closer to 10 hours than the current 18-20 hours?
(I had read that with the new charger, 6.6kW I assume, regular 120V recharge would be halved from 20 to 10 hours, was this a mistake by the writer since it now appears the 6.6 is only for 240V, or is there some other tech that Nissan has announced that would reduce 120V to 10 hours)

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 7:14 am
by Jimmydreams
It all depends on the amp rating of the circuit and breaker that the outlet is attached to. If you're running a 20amp breaker, then the total possible amperage at that outlet is 20. That could be split 10 amps per plug, 15 on one and 5 on the other, or all 20 on one plug. If you're drawing 20 amps on one plug and you plug in a 5amp drill on the other one at the same time.... *click* goes your breaker.

So no, you can't really 'double up' the power by adding a pigtail.

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 7:35 am
by LTLFTcomposite
You might avoid a little overheating of the plug but not a good plan... there is no assurance those two receptacles are "electrically identical". One half could be switched, the two halves could even be on different circuits on opposite phases. If you plugged in two plugs that were wired together you would energized the switched circuit, or worse, PFFFFFTT-click!

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 7:40 am
by evnow
The limitation is 120V , 15 Amps. You can't put to of them in parallel - since the car has only one input. Though it is an interesting idea - if the car had two inputs - you could potentially use 2 120V inputs from two separate circuits and reduce charging time.

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 7:48 am
by LTLFTcomposite
evnow wrote:The limitation is 120V , 15 Amps. You can't put to of them in parallel - since the car has only one input. Though it is an interesting idea - if the car had two inputs - you could potentially use 2 120V inputs from two separate circuits and reduce charging time.
If you could find two receptacles on opposite phases you could rig up a 15amp (or maybe 20) 220v evse. Pretty rube goldberg though.

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 8:23 am
by LEAFer
What you are contemplating ... can be found here: http://www.quick220.com/

This would give you 240V and (theoretically) cut the charging time in half. A Tesla owner has done this (http://www.teslamotorsclub.com/showthread.php?t=2998). But he also uses an intermediate device which solves the problem why I don't think this will work directly on the LEAF. At Level2 charging you need the pilot signal, not just the "juice". I could be wrong ... may be the LEAF can be fooled to think it is doing Level 1 charging (where no pilot signal is needed) but use the 240volts you supply anyway. Now your charging time is cut in half (and using the maximum 3.3kw for the initial LEAFs).

Remember, you need to combine two 120V circuits out-of-phase, but it is worth a try ...

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 8:57 am
by garygid
Typically all the 120v sockets in one room (or both sides of one wall) are wired to one phase, to minimize the amount of wire needed.

CAREFULLY, one could identify two sockets, each on a different phase. Then, by constructing a "Y" type pigtail to plug into both sockets, get 240v, usually from 15-amp breakers (occasionally on 20-amp breakers). NOTE: most people should NOT attempt this.

Assuming the 15-amp breakers, that "connection" could provide 15 x 80% = 12 amps at 240v to power a 240v "EVSE".

However, without the "max current" square wave "control signal" to the car from a 240v EVSE ... the default might be "Error", so the EVSE-compliant LEAF would probably not charge.

Some extra circuitry would probably be required.

For a 120v EVSE, I think there might be a "max current" of 12 amps assumed without the square wave, and that default might also apply to the 240v EVSE.

Without the current J1772 standards document, I do not know for sure.

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 9:05 am
by LEAFer
@Gary: What you describe (quite well) in your first three paragraphs is what the Quick220 does for you -- safely. Which was the point of my post above. Now ... who's got the wherewithal to design the electronics for the pilot signal ?

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 9:39 am
by garygid
I could do the design, if I have the correct standards document, and the necessary information is all there. Sometimes, in "standards", an important detail is left out.

Re: Q: 120V emergency cord

Posted: Thu Jun 24, 2010 10:17 am
by LTLFTcomposite
The possibilities for shoddy half-assed electrical setups are pretty much unlimited. I've got a fair amount of experience doing electrical work though and feel there's a lot to be said for having properly engineered, certified equipment installed as it was intended. That said, you know there are going to be a lot of EV's charged by hot-wiring porch lights. It's all fun and games till somebody loses an eyeball.