Subaru Solterra Forum banner
1 - 20 of 51 Posts

· Administrator
Joined
·
260 Posts
You could pick up one of these.... If you're only using Level 1 for now... I have a similar brand/model to track how much my Christmas lights use for giggles.



Output device Font Data transfer cable Audio equipment Technology
 

· Registered
Joined
·
192 Posts
Well its either 8 amps or 12 amps at 120 volts, for a level 1 charger. Any standard outside socket should do the 8 amps and a robust one will do 12 amps. So its either 1500W or 1000w, depending on what the car's charging system, sees when you hook it up. So an hour for me, my charger will run at 8 amps, is pretty close to a KW/h.

I don't think you need to spend money to look at those numbers on a display, but whatever turns your crank, is fine. ;)
 

· Registered
Joined
·
192 Posts
That is not right. A 1000 watts, a Kilowatt, is the amount of power. Using that for an hour is a kWh. Using a kWh, for an hour is entering dimensional madness, almost like the string theory guys. ;)
 

· Registered
Joined
·
303 Posts
And even with the charge limit (of the Solterra) set to 8A or 16A, the actual current drawn may be less. This is where one of those Kill-A-Watt (brand) 15A (maximum) accumulating meters is handy.

Most of the 240V EVSE with WiFi will also report accumulated kWh.

It’s only the relatively dumb (none are really dumb, because they have to do J1772 negotiation) EVSE that can’t report it.

You can also get a device which clamps around one of the hot wires (in the electrical panel, at the output of the breaker or anywhere along a single conductor of the two hot wires) which can be queried via WiFi. Multiple sensors can be used to determine other circuit power utilization in your house. Various brands like Emporia Vue as an example.
 

· Registered
Joined
·
192 Posts
You get an entire car with quite a quite sophisticated BMS, to say nothing of its programmable charging nature. I am gonna plug mine in to a minimum setup and see what happens. I anticipate somewhere in the 4.5 km per hour, of charging time. So almost 90 km in 20 hours, which very much suits my usage. As well minimum charging is the best way ... if you have the time. ;)
 

· Registered
Joined
·
28 Posts
Discussion Starter · #11 ·
And even with the charge limit (of the Solterra) set to 8A or 16A, the actual current drawn may be less. This is where one of those Kill-A-Watt (brand) 15A (maximum) accumulating meters is handy.

Most of the 240V EVSE with WiFi will also report accumulated kWh.

It’s only the relatively dumb (none are really dumb, because they have to do J1772 negotiation) EVSE that can’t report it.

You can also get a device which clamps around one of the hot wires (in the electrical panel, at the output of the breaker or anywhere along a single conductor of the two hot wires) which can be queried via WiFi. Multiple sensors can be used to determine other circuit power utilization in your house. Various brands like Emporia Vue as an example.
And even with the charge limit (of the Solterra) set to 8A or 16A, the actual current drawn may be less. This is where one of those Kill-A-Watt (brand) 15A (maximum) accumulating meters is handy.

Most of the 240V EVSE with WiFi will also report accumulated kWh.

It’s only the relatively dumb (none are really dumb, because they have to do J1772 negotiation) EVSE that can’t report it.

You can also get a device which clamps around one of the hot wires (in the electrical panel, at the output of the breaker or anywhere along a single conductor of the two hot wires) which can be queried via WiFi. Multiple sensors can be used to determine other circuit power utilization in your house. Various brands like Emporia Vue as an example.
Thanks. FYI: I’m looking to know how much energy is drawn from a 120V (I think) outdoor outlet that I will be using at someone else’s house to charge my car. I want to reimburse them for the cost of the electricity. I’m surprised that a car as sophisticated as the Solterra doesn’t provide the kW usage per charge.
 

· Super Moderator
Joined
·
1,246 Posts
kWh usage per charge. kW is a measure of power, how quickly energy is transferred. kWh is how much energy is transferred.

To compute kWh per charge, multiple 120 (volts) x ___ amps (8 - 12, whatever) x hours plugged in, divided by 1,000. Multiply that result by about 1.1 to account for efficiency loss.

So, at 8 amps, that would be 120 x 8 / 1000 x 1.1 or approx 1.06 kWh per hour of charging time.

At 12 amps, it would be..... (1.5 x that figure) .... approx 1.59 kWh per hour of charging time.

Multiply either figure by the per kWh price the person pays and you'll have your answer.

At $0.10/kWh, that would be either 10.6 cents per hour or 15.9 cents per hour.

Edit: bottom line, you're not going to owe them a lot of money, unless their per kWh price is really high.
For 10 hours of charging that would be $1.06 or $1.59 at 10 cents/kWh. For 20 hours, $2.12 or $3.18.
 

· Registered
Joined
·
7 Posts
To compute kWh per charge, multiple 120 (volts) x ___ amps (8 - 12, whatever) x hours plugged in, divided by 1,000. Multiply that result by about 1.1 to account for efficiency loss.
That would be with 10% loss, but it could be as high as 20%~25% (also depends on length of wiring, wire diameter etc.). Once I get mine I will perform some tests (220V...)
 

· Administrator
Joined
·
260 Posts
I've also found that device to be helpful determining which aging appliance is being extra thirsty while doing its job... Tracking Amps during a cycle startup.
 
  • Like
Reactions: Ducatista and JayEM

· Super Moderator
Joined
·
1,246 Posts
Interesting!

Sense has a similar solution, but it doesn't monitor individual circuits (it uses AI which works - sorta). I've been using that for almost 5 years now, it has yet to identify my EV charging as a distinct "device" - despite its unmistakable usage pattern (the "bumps and spikes" are other devices turning on and off during the night):

Rectangle Slope Plot Font Parallel
 

· Registered
Solterra 2023, Luxury (Limited)
Joined
·
30 Posts
Interesting!

Sense has a similar solution, but it doesn't monitor individual circuits (it uses AI which works - sorta). I've been using that for almost 5 years now, it has yet to identify my EV charging as a distinct "device" - despite its unmistakable usage pattern (the "bumps and spikes" are other devices turning on and off during the night):

View attachment 1555
The IoTaWatt as the advantage to be open so you can more easily access the data stream and configure it, but it also requires to do said programming. The best-buy one, I don't know.

And ya, I don't know what that big chunk of charge is ;)
 
1 - 20 of 51 Posts
Top