MNL vs. other Leaf social media

[mwalsh]

People just want to be "heard," I guess. If I had a dime for every product review or answer to a question about a product that said, in essence, "I don't have one" or "I just bought it but haven't used it yet (or opened it)" or "I don't know" I'd have literally hundreds of dollars.

Isn't that the most stupid thing in the world? I hate it when people do that. The only rational I can think of is that these folks must think they are being asked the question personally, so feel compelled to offer some kind of response.

[Lothsahn]

Later today, in another post, someone at https://www.facebook.com/groups/nissan. ... 722889087/ asks if they install a 240 volt EVSE, will their electricity bill go down vs. how they're charging now (via 120 volts). Of course, another moron comes on and claims it won't at all, mixes up units (talks about watts when he means kWh, says "KW/h", doesn't understand the fixed charging overhead, doesn't even know what we're referring to when we're talking about pumps running, etc.). Sigh...

On a serious note, I'm about to install a 240v EVSE to replace my 120v for my 2011 (3.3 kW charger). How much efficiency would I gain?

[DaveinOlyWA]

Later today, in another post, someone at https://www.facebook.com/groups/nissan. ... 722889087/ asks if they install a 240 volt EVSE, will their electricity bill go down vs. how they're charging now (via 120 volts). Of course, another moron comes on and claims it won't at all, mixes up units (talks about watts when he means kWh, says "KW/h", doesn't understand the fixed charging overhead, doesn't even know what we're referring to when we're talking about pumps running, etc.). Sigh...

On a serious note, I'm about to install a 240v EVSE to replace my 120v for my 2011 (3.3 kW charger). How much efficiency would I gain?

10%. It would be over 15% with 6.6

[Lothsahn]

10%. It would be over 15% with 6.6

Thanks! Is that just due to parasitic drain from cooling pumps, etc, or is the 240V conversion inherently more efficient?

[LeftieBiker]

Mostly it's the run time adding extra drain from the pumps and electronics.

[DaveinOlyWA]

10%. It would be over 15% with 6.6

Thanks! Is that just due to parasitic drain from cooling pumps, etc, or is the 240V conversion inherently more efficient?

Its the BMS/LBC. Conversion efficiency between the voltages I don't know although 240 is likely a higher but probably not significantly so.

the issue is the inverter that changes AC from your wall to DC to store into the battery. The conversion creates a lot of heat so a cooling system is needed. This means pumps, etc. Now, the pumps do have variable speeds but not many steps which means power usage from the pump varies little between 120 and 240.

Add it up and you have a near equal level of power being taken from the wall that does not go to the battery. So its 250 watts. So you got 1440 watts coming in minus the 250 or 1190 watts or 82.6% of the power from the wall into the battery.

Take the 240 feed. It has several current options but if taking the max of 27.5 amps we have 6600 watts minus the same 250 or 6350 watts or 96% of the power from the wall into the battery.

Now, there are several other lesser factors to consider including battery temps, etc. including the losses that can go as high as 350 watts (more or less) and so on but even if we use the lower number for 120 volts and the higher number for 240 volts, the difference is still quite extreme.

Several years ago, (before LEAF Spy) I installed a utility grade meter inline with my EVSE and found a rough efficiency of

75% on 120 volt, 12 amp
83% on 240 volt, 12 amp
88% on 240 volt, 20 amp

Now the meter was analog so I logged only whole kwh readings. IOW; the efficiencies were determined from data collected over several weeks.

[WetEV]

Its the BMS/LBC. Conversion efficiency between the voltages I don't know although 240 is likely a higher but probably not significantly so.

Based on smaller converters I've worked on and with, probably a couple of percent more efficient at 240V.

[LeftieBiker]

Add it up and you have a near equal level of power being taken from the wall that does not go to the battery. So its 250 watts. So you got 1440 watts coming in minus the 250 or 1190 watts or 82.6% of the power from the wall into the battery.

17.4% lost isn't "a near equal level of power being taken from the wall that does not go to the battery." It's less than 20%. You may want to edit that.

[Lothsahn]

Add it up and you have a near equal level of power being taken from the wall that does not go to the battery. So its 250 watts. So you got 1440 watts coming in minus the 250 or 1190 watts or 82.6% of the power from the wall into the battery.

17.4% lost isn't "a near equal level of power being taken from the wall that does not go to the battery." It's less than 20%. You may want to edit that.

His point was the pump parasitic draw was near equal regardless of incoming charge rate. 250 watts.

Thank you Dave for taking the time to write such a detailed response. Makes a lot of sense!

[LeftieBiker]

Add it up and you have a near equal level of power being taken from the wall that does not go to the battery. So its 250 watts. So you got 1440 watts coming in minus the 250 or 1190 watts or 82.6% of the power from the wall into the battery.

17.4% lost isn't "a near equal level of power being taken from the wall that does not go to the battery." It's less than 20%. You may want to edit that.

His point was the pump parasitic draw was near equal regardless of incoming charge rate. 250 watts.

Thank you Dave for taking the time to write such a detailed response. Makes a lot of sense!

I read it four times, and now I'm not sure which he means. With everyone else I've ever read saying that the loss is substantially lower with 240 volts, I'm going to have to take it with a grain of salt.