Estimating what I owe my kid when we charge at her place

[mapman]

We're still looking forward to our M3LR delivery. Our Wall Connector is ready and waiting.

We'll visit our kid hundreds of miles away fairly often, and we'll use the mobile connector to charge at her place. Can I tell the amount of power we draw from the mobile connector there (distinct from what we do at home or at Superchargers)?

Thanks

 

[Black306]

Owe?? Just call it mommy/daddy tax.

Yes, there is a Charge Stats section in the app that’ll tell you how many kWh was charged for a given day.

 

[father_of_6]

Yeah, you owe her nothing. You wiped her butt as a baby.

 

[jjrandorin]

We're still looking forward to our M3LR delivery. Our Wall Connector is ready and waiting.

We'll visit our kid hundreds of miles away fairly often, and we'll use the mobile connector to charge at her place. Can I tell the amount of power we draw from the mobile connector there (distinct from what we do at home or at Superchargers)?

Thanks

Totally get the sentiment, but you definitely will be costing them more eating every day than you will be costing them in electricity. As was already said, I think the charging stats in the app can help you figure this out, as well as any one of the several popular third party data collection tools if you want to go that route.

Buying them dinner, even once, would likely quadruple pay it back, though.

 

[mapman]

Fair enough. Thanks all!

 

[jjrandorin]

Fair enough. Thanks all!

No worries.

If your daughter / daughters family are any sort of "EV hesitant" / "Anti EV", it might be worth gathering the data anyway, and slipping them something to cover it. It wont be very much money, but if they are "not sure" about EVs per se, it might nip any potential talking points in the bud, so to speak.

 

[3sr+buyer]

If you know their electricity rate and how much you got from their outlet, you can estimate the amount your charging adds to their electric bill.

 

[AlanSubie4Life]

If you know their electricity rate and how much you got from their outlet, you can estimate the amount your charging adds to their electric bill.

The Tesla app appears to account for charging losses, FWIW (it will not match the “kWh added” in the car display before you unplug it). Whether this is a fixed assumed percentage efficiency or whether they do the correct thing and integrate I*V over time (power factor presumably a non-issue) I don’t know, but I assume they do it correctly.

So just the rate is needed.

Maybe substantial caveats if pre-heating is used, etc. The app may not be a perfect tracker.

 

[father_of_6]

If they live in Hawaii, they might be paying as high as $.45 per kWh. The largest Model 3 battery is 82kWh.

Worst case scenario, your "full tank" 0-100% charge could cost $37 plus a bit more for inefficiencies. Perhaps you plan to stay there for a long time and do lots of driving while you're there.

In my mind though, I'm imagining you'll barely need charging and the rate is more like $.13 per kWh.

Maybe there is merit to determining the actual costs and paying them for it... but my guess is you'll cost them something negligible like $9 / week at most.

 

[DuncanM]

Totally get the sentiment, but you definitely will be costing them more eating every day than you will be costing them in electricity. As was already said, I think the charging stats in the app can help you figure this out, as well as any one of the several popular third party data collection tools if you want to go that route.

Buying them dinner, even once, would likely quadruple pay it back, though.

The M3LR has about 75kwh of usable capacity, so each 1% of charge = ~.75kw x charging losses = ~.8kw used per percent of charge.

So a 30-80% charge (50%) charge = ~40kw x their metered rate per kw, or somewhere between $4 and $10, at typical rates.

Remember to set your maximum amp limit to an appropriate value for their electrical outlet.

 

[3sr+buyer]

Remember to set your maximum amp limit to an appropriate value for their electrical outlet.

The mobile connector plug adapter will do that, unless you suspect that the circuit cannot handle the current it is rated for (e.g. 5-15 shared with other stuff).

 

[Lindenwood]

I use a 10-30 to 14-50 adapter when I need to plug into old dryer outlets and manually adjust down the current (to below even normal 10-30 capabilities to account for the adapter losses).

If I roll in with 10% and charge to 90%, I am looking at around $8-10 at most places.

I’d say odds are you will be buying your fair share of meals, babysitting the grandkids, etc, so hopefully they don’t make a fuss over $10-15 per trip.

 

[mikeskuro]

My parents have an ioniq5 and I have a MYLR, previously M3LR. They just visited for the first time since going electric and I did what they do for me when ever I visited prior(they have had a NEMA 14-50 since 2018). Hand over the spare garage door opener and they plug right in and charge.

Making a visit and seeing people, spending the night in ones home(parents or not) and sharing some electrons makes getting there, traveling locally for activities or leaving a part of being there and a contribution of the host. My 2 cents.

 

[DuncanM]

The mobile connector plug adapter will do that, unless you suspect that the circuit cannot handle the current it is rated for (e.g. 5-15 shared with other stuff).

That's the thing. A NEMA 5-15 can nominally run at 12amps, but pulling 12amps for 10-40 hours might be problematic in terms of excessive heating of the connectors, wire or breaker. 8-10amps might be safer for very long charging sessions. It might also be a good idea to inspect the wiring and panel to see if an upgrade might be in order.

 

[pipp]

Find out their rate, look at their meter when you get there, look at it again when you leave, then offer to pay them for all electricity used by everybody during your visit. Then you can have an awkward 15-minute semi-argument where they tell you not to worry about it but you insist on worrying about it.

 

[father_of_6]

Find out their rate, look at their meter when you get there, look at it again when you leave, then offer to pay them for all electricity used by everybody during your visit. Then you can have an awkward 15-minute semi-argument where they tell you not to worry about it but you insist on worrying about it.

I recommend doing the same thing with the toilet paper. Measure the size of the roll with your micrometer when you get there, then once again right before you leave, then offer to pay them for everyone's TP during your visit. Then you can have an awkward 20-minute semi-argument about why grandma uses *so* much toilet paper.

 

[mapman]

My kid's housemate pays that electric bill, so it's helpful for her to know.

Let's leave toilet paper out of it

 

[Big Earl]

My kid's housemate pays that electric bill, so it's helpful for her to know.

Let's leave toilet paper out of it

Your app and screen will tell you how many kWh you’ve added in a charging session. Simply multiply by their loaded (total bill divided by total kWh) electricity rate. Add 10% to cover efficiency losses.

 

[Rocky_H]

We'll visit our kid hundreds of miles away

If they live in Hawaii,

OP lives out in the Pacific Ocean.

 

[3sr+buyer]

That's the thing. A NEMA 5-15 can nominally run at 12amps, but pulling 12amps for 10-40 hours might be problematic in terms of excessive heating of the connectors, wire or breaker. 8-10amps might be safer for very long charging sessions. It might also be a good idea to inspect the wiring and panel to see if an upgrade might be in order.

Often, the bigger issue with 5-15 (typical household 120V outlets) is that they can be on circuits shared with other outlets that may have things with significant current draw plugged into them. So a 5-15 outlet on a circuit capable of 12A with just an EVSE plugged into it may be overloaded if the EVSE is taking 12A and then something else plugged into the same circuit is turned on.

While very recent electrical codes may specify a dedicated outlet in the garage for each parking space, many older garages have outlets that are on circuits shared with other outlets in the house.

Another issue is that an outlet that has been plugged and unplugged frequently may be worn out so that it no longer tightly grips the plug blades.