What Max Amperage to Consider for Home Charging? (40, 48, 80)

[lg3103]

My ChargePoint Home Flex on the 60A breaker now charges the Rivian close to max vehicle capacity. With the 50 breaker it ran at 9.5-9.7. In Colorado on Xcel TOU rate between 9pm-6am. This give me 100kwh over night if I need that much

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[countab45]

i leave mine at 28a to reduce fire risk given my old breakers and nema 14-50 setup. 7kw per hour. so 20-80% in 10-11 hours.

 

[jollyroger]

So just as a follow up I decided to run a 100 amp circuit to a new sub-panel in the garage with a 70 amp circuit to the EVSE. The sub-panel is right next to the EVSE so it functions as a local disconnect.

Running #2 wire between the main panel and the subpanel, and #6 between the subpanel and the EVSE (Chargepoint Home Flex). So now if we ever upgrade the EVSE, all we need to worry about is the 2 feet between the sub-panel and the EVSE.

I hope they don't just make a new J1772 standard that supports up to 180 amps

 

[evguy]

The only exception is for those people who are on time-of-use plans, they would want to charge as fast as possible because they can't just leave it charging for 12 hours. I have a flat rate so our 40a charger is enough, but I could see why some people want more amperage.

I'm one of those people, and you are correct. On our TOU plan, the off-peak window is only 6 hours (12-6 am). We have a Rivian charger on a 60A circuit and get about 22 mi of range per hour, for a max total of about 132 miles added range during that window. That's enough for our daily use case, charging to 70% overnight and still having more than 20% "in the tank" at the end of the day.

 

[av8or]

So just as a follow up I decided to run a 100 amp circuit to a new sub-panel in the garage with a 70 amp circuit to the EVSE. The sub-panel is right next to the EVSE so it functions as a local disconnect.

Running #2 wire between the main panel and the subpanel, and #6 between the subpanel and the EVSE (Chargepoint Home Flex). So now if we ever upgrade the EVSE, all we need to worry about is the 2 feet between the sub-panel and the EVSE.

I hope they don't just make a new J1772 standard that supports up to 180 amps

That’s a nice setup for now and future use. Well done. ????. I have the chargepoint home flex on a 60 amp breaker and love it. At 23 miles an hour it‘s pretty easy to get to 70% daily, it’s roughly 1.2 hours per 10% gain.

 

[emoore]

So just as a follow up I decided to run a 100 amp circuit to a new sub-panel in the garage with a 70 amp circuit to the EVSE. The sub-panel is right next to the EVSE so it functions as a local disconnect.

Running #2 wire between the main panel and the subpanel, and #6 between the subpanel and the EVSE (Chargepoint Home Flex). So now if we ever upgrade the EVSE, all we need to worry about is the 2 feet between the sub-panel and the EVSE.

I hope they don't just make a new J1772 standard that supports up to 180 amps

Well even if there is a new higher amperage standard the Rivian will still be limited to 48 amps. And I thought Xcels TOU off peak was 7pm to 1pm for the Denver area?

 

[Dark-Fx]

I'm one of those people, and you are correct. On our TOU plan, the off-peak window is only 6 hours (12-6 am). We have a Rivian charger on a 60A circuit and get about 22 mi of range per hour, for a max total of about 132 miles added range during that window. That's enough for our daily use case, charging to 70% overnight and still having more than 20% "in the tank" at the end of the day.

I'd probably consider putting in a DCFC at home if my off-peak was that short. There's been occasions where I've gotten home with a nearly dead battery around midnight on Sunday and it wasn't enough to get me back up to 85% for the next day.

 

[JohnB R1T]

I'd probably consider putting in a DCFC at home if my off-peak was that short. There's been occasions where I've gotten home with a nearly dead battery around midnight on Sunday and it wasn't enough to get me back up to 85% for the next day.

You can pay for a hell of a lot of non-off-peak kWh for the cost of even a smaller DC charger.

 

[evguy]

I'd probably consider putting in a DCFC at home if my off-peak was that short. There's been occasions where I've gotten home with a nearly dead battery around midnight on Sunday and it wasn't enough to get me back up to 85% for the next day.

Six hours charging at 48A is plenty for our day to day, but I'd be nervous at less than 48A. As the industry evolves, I just hope the trend is toward making battery packs more efficient instead of just making them bigger. I have to think that will be the case given the scarcity of materials and search for every competitive edge.

 

[invernite]

Above 60A requires a locally accessible disconnect according to code. It actually makes it easier to plan for an upgrade. I ran wiring to a fused disconnect to support the 100A (80A continuous load), with a 100A breaker in the panel and 60A fuses to my hardwired 48A charger.

Wiring from the disconnect is short and a smaller gauge wire that will most likely just get recycled if/when we upgrade the EVSE to an 80A one to support a future vehicle.

Does the fused disconnect require anything else other than the conduit coming into it from the panel and the conduit going out of it to the charger?

https://img.c3controls.com/image/up...sed-Disconnect-Switch-vs-Circuit-Breakers.pdf says "Similar to a circuit breaker, a disconnect switch is normally enclosed in a steel enclosure. The NEC requires that installers mount UL-listed cam-type outlets on an aluminum panel at the bottom of each enclosure. This serves to eliminate the risk of hysteresis."

I would have thought that a standard fused disconnect switch like https://www.homedepot.com/p/Siemens...e-Safety-Switch-with-Neutral-GF223N/205623364 would be sufficient, but not sure.

 

[Firewired]

I have two chargers daisy chained on a 100amp line for both our EVs. It provides 50amps per charger and with that I am charging at 25 miles an hour, which is the max that I have seen anyone reporting able to get from a home charger.

 

[Krs71]

Just to clarify, I just got a ChargePoint and it's a plug setup 14-50, with a 60 AMP breaker and I'm only getting 9.2-9.6 kwh, that's normal? I had a BourgeRV charger that gave me 11.2 kwh consistently without issues.

 

[jollyroger]

Just to clarify, I just got a ChargePoint and it's a plug setup 14-50, with a 60 AMP breaker and I'm only getting 9.2-9.6 kwh, that's normal? I had a BourgeRV charger that gave me 11.2 kwh consistently without issues.

Somethings not adding up here, a 14-50 is a 50 amp max plug, how did you get a 60 amp circuit on there, that said I think the Chargepoint limits to 40 amps of charging if using a plug, which is 80% of what the plug should be supporting. Chargepoint only goes up to 50 amps if it's hardwired.

Edit: Spelling

 

[teartags]

What VOLTS are you all charging at?
I recently had to step down my charger at home to 40A (long story that thankfully didn't end up in a fire) and I'm getting 21-22 miles per hour but it's charging at 240V
My work charger is still at 48A but it's getting the same mileage because my work panel is 208V
Amps = Watts/ Volts

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