80 Feet run for AWG 6/3 wire

[Zoidz]

This detail is key for the OP. The ChargePoint Home Flex can accept a maximum of 6 AWG so 4 AWG into the ChargePoint is not an option. This is also why hard wiring the ChagePoint for 48A charging requires 6 AWG THHN instead of NM-B (Romex).

Edit: I am most definitely not an electrician so not sure about compliance on this but it may be possible to run 4 AWG to a junction box near the charger and then run 6 AWG wire to the Home Flex from there. You'd definitely still be limited to a 60 A breaker in this scenario but if you needed more in the future, it would only require rewiring between the junction and the charger (likely to happen anyway if future EVSE comes with a pigtail) and swapping the breaker as opposed to replacing an entire 80 ft run.

There are a couple of options for this wire size issue. In all cases the breaker must be rated for the #6 wire, not the #4:
1) As you mention, install a box and pigtail the #4 to #6. For this size wire, do it right by using the butt splice or split bolt , not wire nuts. This could possibly be done inside the EVSE if space permits.
2) If running #4 stranded wire THHN/THWN, you could remove a strand or two so that it just fits tightly under the #6 sized terminal. Yes, we could debate that removing too many strands will reduce the effective wire to less than #6. If that is concerning, just do #1 above.

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[Gsxr150]

By the way...for this charged I think you need 6/2 NM. Not 6/3. Can someone confirm?

 

[Eeyore]

It's not very common for household breakers to be 90C rated though.

You are correct. Furthermore, the temperature rating for the whole circuit can be no higher than the lowest rated component. That means you have to rate the ampacity of the wire based on that temperature. So, even though there is a 90 degree column on the wire ampacity chart, you can't use it. Most components are rated at 75 C at most.

 

[nieder]

Charging fast sounds cool but in my experience driving a full EV for the last 6 years, I’ve never needed to charge at more than 32 amps.

I like to look at the situation a little more practically. There isn’t a night where my current EV doesn’t sit still in my driveway for less than 10 hours. My Rivian will be the same.

So for some math; 10 hours x 32a x 240V = 76,800Wh put into your vehicle (ignoring AC/DC conversion losses). The Rivian will get at least 2 miles per kWh so that means each night, I’m enabling 153.6 miles of driving the next morning which is more than I would ever do in a day 99.9% of the time. This also doesn’t account for the SOC the vehicle comes home at night with, which won’t be 0.

If as the OP suggested, he puts in a 14-50 and charges at 40A, he gets 192 miles of range from a 10h charge.

 

[nc10]

This also doesn’t account for the SOC the vehicle comes home at night with, which won’t be 0.

And you may be targeting a 70%, not 100% end point most days.

 

[Rousie13]

Charging fast sounds cool but in my experience driving a full EV for the last 6 years, I’ve never needed to charge at more than 32 amps.

I like to look at the situation a little more practically. There isn’t a night where my current EV doesn’t sit still in my driveway for less than 10 hours. My Rivian will be the same.

So for some math; 10 hours x 32a x 240V = 76,800Wh put into your vehicle (ignoring AC/DC conversion losses). The Rivian will get at least 2 miles per kWh so that means each night, I’m enabling 153.6 miles of driving the next morning which is more than I would ever do in a day 99.9% of the time. This also doesn’t account for the SOC the vehicle comes home at night with, which won’t be 0.

If as the OP suggested, he puts in a 14-50 and charges at 40A, he gets 192 miles of range from a 10h charge.

This exactly. We have had EVs for a few years and we have been a completely EV family for 1 year now (2 EVs). We have a 50A circuit with two hardwired Wallbox units. So if both vehicles are charging, then we are maxed out at 20A per vehicle. We have never had a situation where either vehicle wasn’t charged to where we wanted it when we needed the car.

I understand that having the fastest charging speed available at home is great, but it is not a MUST for most people.

I can understand people wanting the fastest charging speed possible if they have off peak EV charging rates and are trying to charge the vehicle in that window as fast as possible.

 

[CommodoreAmiga]

By the way...for this charged I think you need 6/2 NM. Not 6/3. Can someone confirm?

The Rivian Wall EVSE only uses L1, L2, and ground — so 6/2 is all that’s required. However, running a neutral may still be desired for future use with another device.

 

[Zoidz]

Charging fast sounds cool but in my experience driving a full EV for the last 6 years, I’ve never needed to charge at more than 32 amps.

I like to look at the situation a little more practically. There isn’t a night where my current EV doesn’t sit still in my driveway for less than 10 hours. My Rivian will be the same.

So for some math; 10 hours x 32a x 240V = 76,800Wh put into your vehicle (ignoring AC/DC conversion losses). The Rivian will get at least 2 miles per kWh so that means each night, I’m enabling 153.6 miles of driving the next morning which is more than I would ever do in a day 99.9% of the time. This also doesn’t account for the SOC the vehicle comes home at night with, which won’t be 0.

If as the OP suggested, he puts in a 14-50 and charges at 40A, he gets 192 miles of range from a 10h charge.

I agree that this might fit many (most?) use cases, but there are some of us who live stupid busy schedules, such as driving 200+ miles in a day, getting home at midnite, and leaving on another 200+ mile trip at 6 AM. I’ll take the fastest rate I can get for a few hundred dollars additional installation cost.

The same thought for the neutral - I’ll run a neutral for the small extra cost, as opposed to trying to retrofit if needed in the future.

 

[ksujeff99]

For those that have been around EVs longer, any idea what amperage is the most efficient? Best for the battery?

At what amperage is
1) the voltage loss/heat gain the lowest on the wiring to/from the EVSE?
2) the in-vehicle inverter the most efficient?
3) the least heat generated by the battery when charging?

I’ve noticed that charging at 48a, both the wiring leading to my EVSE and the cable from the EVSE to my R1T get pretty warm. That’s lost energy. How low can you drop the amperage before you get to the point of diminishing returns? Or to the point that the inverter becomes inefficient?

 

[michaelcasto]

Hello

So I am new to the EV world. Getting my truck delivered next week - I have decided to get the Chargepoint Home Flex (NEMA 14-50) EVSE installed in the garage. THe panel is on the opposite side to the garage and so we have about a 80 Feet run. The electrician is going to install a 50Amp breaker with the 14-50 outlet and 6/3 wire.

My question is - will that be too much of a drop in the voltage with the 80' run and hence extra charging time? OR is it not that big a difference?

Many thanks in advance!

THanks
RS

Dont use any size bigger than 6 awg wire from instruction manual! My electrician used 4awg and now my charger isn’t working properly and cutting off.

 

[michaelcasto]

It's not very common for household breakers to be 90C rated though.

Just talked with a member of charging team at Rivian and he said nothing other than 6 AWG wire is supposed to be used. My electrician installed with 4 and 2 gauge wires and my charger has been cutting off after about 10min of charging.

 

[capitolm94]

I have a similar setup- ChargePoint home flex hardwired with 6 wire to a 60a breaker on the other side of the garage. Working great, chargers at 11.5 kW.

Also the speed does matter. While the truck does sit there all night, I only have a 6 hr window 12-6 am where electricity is priced at the lowest rate, so I want all the charging to get done during that time period.

 

[SANZC02]

I have a similar setup- ChargePoint home flex hardwired with 6 wire to a 60a breaker on the other side of the garage. Working great, chargers at 11.5 kW.

Also the speed does matter. While the truck does sit there all night, I only have a 6 hr window 12-6 am where electricity is priced at the lowest rate, so I want all the charging to get done during that time period.

I see you are in Orange County, CA. Curious what rate you have from midnight to 6AM and what power company? I have SCE and do not see a rate lower those times, my off peak is pretty much the same for anything outside of 4PM-9PM, would love to find something lower if it is available.

 

[capitolm94]

I see you are in Orange County, CA. Curious what rate you have from midnight to 6AM and what power company? I have SCE and do not see a rate lower those times, my off peak is pretty much the same for anything outside of 4PM-9PM, would love to find something lower if it is available.

SDGE- there are a million plans, but I am on EV-Tou-5, which has super off peak from 12-6 on weekdays at .15 per kWh, you pay $16 a month to get that. With the solar system plus that plan the cost is pretty reasonable to charge.

 

[SANZC02]

SDGE- there are a million plans, but I am on EV-Tou-5, which has super off peak from 12-6 on weekdays at .15 per kWh, you pay $16 a month to get that. With the solar system plus that plan the cost is pretty reasonable to charge.

Thanks, was thinking I might have missed something on the SCE plans.

I added Solar a couple of years ago and was able to get 2x my average daily use approved for the NEM program because I had an EV and a Rivian on order. Just got the Rivian in January, so far still generating more each month than we are using but at 22 cents in winter and 24 cents in summer would have been nice for the times I mIght go over if there was a better rate.

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