Charging speed at home vs work

[krafty81]

My work charger is free but very slow. Takes me all day to add about 50%.

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[RMoore]

My work charger is free but very slow. Takes me all day to add about 50%.

That’s in line with the calculations in my post and in those of others. 6-7 kW is apparently typical for a work L2 charger. That would translate to 48-56kWh for a 9-5 workday, not counting losses. That amounts to about 50% of charge added.

 

[SnBGC]

That’s in line with the calculations in my post and in those of others. 6-7 kW is apparently typical for a work L2 charger. That would translate to 48-56kWh for a 9-5 workday, not counting losses. That amounts to about 50% of charge added.

Which would be necessary if you consume 50% of your capacity just to get to work. I consume about 7% getting there and about 8% coming home.

 

[RMoore]

Home: 40A x 238V = 9.5 kW
Work: 32A x 188V = 6.0 kW

Chargers at work are often 208V instead of 240V, which will reduce charging speed. In addition, they are often 32A or less vs. 40 or 48A for home chargers. Last, chargers at work are often outside a long distance from the panel, so they tend to have high voltage drops which also reduces charging speed.

As others have said, load sharing is a possibility, every setup is different. If you have load sharing you may notice a big difference in charging speed from day to day depending on who is plugged in when. At my work there is no load sharing but we only have a couple chargers. Load sharing is more likely in larger installs (5+ stations).

I was put in touch with someone at work whom I was told has knowledge of the charging setup. Here is what he said:

• Tesla standard connectors – 200-277V, 80A, 60Hz, single phase
• Tesla Universal connectors – 200-240V, 40A, 60Hz, single phase

So the Tesla standard ones are on an 80A circuit? Does that mean I shouldn't even try to use my TeslaTap mini 60A or, given the 80% rule, is it likely to be ok?

 

[Mach-Lee]

I was put in touch with someone at work whom I was told has knowledge of the charging setup. Here is what he said:

• Tesla standard connectors – 200-277V, 80A, 60Hz, single phase
• Tesla Universal connectors – 200-240V, 40A, 60Hz, single phase

So the Tesla standard ones are on an 80A circuit? Does that mean I shouldn't even try to use my TeslaTap mini 60A or, given the 80% rule, is it likely to be ok?

Those seem like the ratings (maximum) off the nameplate stickers, not their actual power. You’ll have to use a scan tool and Car Scanner to read the actual charger voltage and current when plugged in.

 

[RMoore]

Those seem like the ratings (maximum) off the nameplate stickers, not their actual power. You’ll have to use a scan tool and Car Scanner to read the actual charger voltage and current when plugged in.

Is there any reason why they would set up the universal charger on a 40A circuit vs Tesla specific ones on 80A?

So if I had an OBD reader and Car Scanner, it would show the actual charger voltage and current; I assume if the charger was truly on an 80A circuit it would be capable of delivering more current than the MME can accept (assuming no load sharing), in which case it would be capped and Car Scanner would show that max.

 

[Mach-Lee]

Is there any reason why they would set up the universal charger on a 40A circuit vs Tesla specific ones on 80A?

So if I had an OBD reader and Car Scanner, it would show the actual charger voltage and current; I assume if the charger was truly on an 80A circuit it would be capable of delivering more current than the MME can accept (assuming no load sharing), in which case it would be capped and Car Scanner would show that max.

Not really, those were just the max amps for each version. Teslas with dual chargers that can charge at 80A are very rare so I’m almost sure those are put on a much smaller circuit. The J1772 version only came in 40A. Sounds like they are using Gen 2 wall connectors. They are all probably on 40A breakers putting out 32A. You can check the duty cycle parameter with car scanner to determine the maximum the charger is offering.

 

[RMoore]

You can check the duty cycle parameter with car scanner to determine the maximum the charger is offering.

Thanks. Would an OBD reader with Car Scanner tell me what the charger can do or only what the MME can accept (or is accepting)?

 

[Mach-Lee]

Thanks. Would an OBD reader with Car Scanner tell me what the charger can do or only what the MME can accept (or is accepting)?

Both. The max for the mach-e is 48A or 11.5 kW, whichever is reached first.

 

[macchiaz-o]

I was put in touch with someone at work whom I was told has knowledge of the charging setup. Here is what he said:

• Tesla standard connectors – 200-277V, 80A, 60Hz, single phase
• Tesla Universal connectors – 200-240V, 40A, 60Hz, single phase

So the Tesla standard ones are on an 80A circuit? Does that mean I shouldn't even try to use my TeslaTap mini 60A or, given the 80% rule, is it likely to be ok?

The Mach-E won't attempt to pull more than 48A into its on board charger. So as long as you're comfortable with using that extra adapter in the middle of the connection, and the adapter truly is rated for 60 amps, then you're good to go.

 

[Ming]

I was put in touch with someone at work whom I was told has knowledge of the charging setup. Here is what he said:

• Tesla standard connectors – 200-277V, 80A, 60Hz, single phase
• Tesla Universal connectors – 200-240V, 40A, 60Hz, single phase

So the Tesla standard ones are on an 80A circuit? Does that mean I shouldn't even try to use my TeslaTap mini 60A or, given the 80% rule, is it likely to be ok?

Those are the specs of the chargers, not actual supply numbers. The easiest is asking someone charging their Tesla, what's shown on their phone app during charging. Note if the charges are configured for load sharing, the numbers would be different with multiple cars are charging at same time.

 

[RMoore]

Thanks for all the helpful responses, much appreciated!

 

[RMoore]

Addendum: we’ll, as I posted in my other thread about not getting my TeslaTap mini to work, I tried again today at work but couldn’t get it all the way on. The fit is too tight even with some Teflon lubricant. So I will only be charging at work using the Tesla destination chargers that have J1772 cables, at least for the near future.

 

[Ming]

Addendum: we’ll, as I posted in my other thread about not getting my TeslaTap mini to work, I tried again today at work but couldn’t get it all the way on. The fit is too tight even with some Teflon lubricant. So I will only be charging at work using the Tesla destination chargers that have J1772 cables, at least for the near future.

Would sanding the adapter a little bit work?

 

[RMoore]

Would sanding the adapter a little bit work?

I wondered about that as well since I’ve done similar things in the past. I think it would be challenging given that I would need to sand the inside surface and it would be difficult to do it evenly I think given that there are the connectors there. It would be a last ditch effort if I can’t return or exchange it, or sell it.

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