Charging but not.

[mjwhite130]

Hey guys super noob here. Did some forum searching and i think i have the answer but thought i’d get the consensus.

Got my MY a week ago been using just the 115v in the garage overnight and its been normally at 4 kw/h (added 31 miles) last night 8 hrs. ( i know i’m switching metrics here) Anyway after a short trip this morn came back home and plugged in for the 2 hrs before leaving to work and was getting 0 kw/h but the time to full was still counting down. And counting down at a rate that would put me at 290 miles in 24 hrs. Which my crude math would be (4mi per hr like last night)
I gained only 2 miles in this two hr charge. Strange
My guess car sees the circuit cant take the 10A charge but still shows its charging at that but only maybe 1/2-1 kw/h.
Sorry for all the switching back and forth. My electricity background is i know how to let smoke out of the wires.

Thanks

 

[Sophias_dad]

What was the ambient temperature both before and after the short trip? A short trip won't warm the battery much, so 100% of the input power was going to warm the battery. This is why 120V charging is discouraged.

If it is likely to become an issue for you, you >might< be able to use a 15-20 adapter(assuming its a 20 amp outlet already), but it sounds like the car is already turning down the current because its seeing voltage going down, so that probably wouldn't help all that much. If its a dedicated(single. alone) outlet, you might be able to turn it into a 240V/15A outlet and double your charging rate. It might still not always be nonzero, but it would take much less time to actually start charging.

 

[mjwhite130]

What was the ambient temperature both before and after the short trip? A short trip won't warm the battery much, so 100% of the input power was going to warm the battery. This is why 120V charging is discouraged.

If it is likely to become an issue for you, you >might< be able to use a 15-20 adapter(assuming its a 20 amp outlet already), but it sounds like the car is already turning down the current because its seeing voltage going down, so that probably wouldn't help all that much. If its a dedicated(single. alone) outlet, you might be able to turn it into a 240V/15A outlet and double your charging rate. It might still not always be nonzero, but it would take much less time to actually start charging.

Ahhhh it was probably about 60 degrees F this morning. Drove 5 miles car sat for an hr and a half then 5 miles home. Seemed to charge fine although slow with this trip before but i’ll keep that in mind.
And yes this is a shared circuit old condo etc etc. Thinking of seeing if possible to run a dedicated. Probably come back to the forum for suggested electricians. Thanks for the reply.

 

[jcanoe]

A few things:

The temperature in Garden Grove, CA is currently 51F, overnight the same. That should not be cold enough to require extensive battery warming prior to being able to charge.

How old is the NEMA 5-15 receptacle you are using? If over 5 years (certainly if older than 10 years) the receptacle should be replaced.

31 miles in 8 hours (~4 miles per hour) would be what you could expect from 120V/12A charging. It appears that the Tesla vehicle may have recently started reducing the charging amperage. The maximum charging amperage for the 15A circuit would be 12A (1.44kW charging rate) in response to either a voltage drop or the power plug getting too warm.

Suggest you try charging at another location (use Plugshare to locate public Level 2 charging locations near you. (You will need to use the Tesla SAE J1772 adapter that came with your Tesla Model Y to use any non-Tesla Level 2 charging station.)

Alternately you could use a Supercharger if one is nearby. Don't waste time at a Supercharger; only use a Supercharger when the battery is at 50% or below and then charge only to 80%.

 

[mjwhite130]

A few things:

The temperature in Garden Grove, CA is currently 51F, overnight the same. That should not be cold enough to require extensive battery warming prior to being able to charge.

How old is the NEMA 5-15 receptacle you are using? If over 5 years (certainly if older than 10 years) the receptacle should be replaced.

31 miles in 8 hours (~4 miles per hour) would be what you could expect from 120V/12A charging. It appears that the Tesla vehicle may have recently started reducing the charging amperage. The maximum charging amperage for the 15A circuit would be 12A (1.44kW charging rate) in response to either a voltage drop or the power plug getting too warm.

Suggest you try charging at another location (use Plugshare to locate public Level 2 charging locations near you. (You will need to use the Tesla SAE J1772 adapter that came with your Tesla Model Y to use any non-Tesla Level 2 charging station.)

Alternately you could use a Supercharger if one is nearby. Don't waste time at a Supercharger; only use a Supercharger when the battery is at 50% or below and then charge only to 80%.

Ok copy that. Yeah plug is old. I set the amps at 10. Like i said it was working fine i just happened to look before work and see this. And i will prob be using a supercharger once a week on my friday got on 4 miles from me. You guys are on it. Thanks for the reply

 

[Benito1283]

Also curious about your temps there. But it looks like the overnight lows in Garden Grove CA are 45F. That shouldn't be cold enough to prevent adding range, unless your battery was insanely cold for some reason. I charged successfully, albeit slowly, for months on a 5-20 (120V 16A max) down to 10F overnight. Sometimes the first 30-60 min I would get the "24+hr remaining" until the battery was sufficiently warmed, but then it added range just fine, at 6-7 mph.

Any reason you're limiting to 10 amps? I would give it everything you've got and increase to 12A. This might be enough to make a difference. Ignore the charging ETA for half hour or so.

And like Sophias_dad mentioned, if this is the only outlet on your circuit, or if you're able dedicate the entire circuit to car charging, an electrician can *easily* convert this to a 240V/15A outlet. Better yet, if it has 12 gauge wire back to the panel, you could convert to 240V/20A. Either option would be a fantastic upgrade without running new wire. An electrician should be able to do this in under an hour.

 

[jcanoe]

Ok copy that. Yeah plug is old. I set the amps at 10. Like i said it was working fine i just happened to look before work and see this. And i will prob be using a supercharger once a week on my friday got on 4 miles from me. You guys are on it. Thanks for the reply

You can only safely set the 120V charging amperage to 12A (when using a 15A circuit) if you know that there are no other electrical appliances in use on the same circuit. (GM for example, defaults the maximum charging amperage in this scenario to 8A, GM plug-in and electric vehicle owners need to manually change the setting for the home location to be able to charge at 12A.)

If you end up needing to install a new charging circuit but there is limited capacity available then a 240V/20A circuit is a decent introduction to Level 2 charging. (3.8kW gets you up to 14 miles of range per hour when charging.) The relevant Tesla NEMA power plug adapter is the NEMA 6-20.

 

[Mrbrock]

You can only safely set the 120V charging amperage to 12A (when using a 15A circuit) if you know that there are no other electrical appliances in use on the same circuit. (GM for example, defaults the maximum charging amperage in this scenario to 8A, GM plug-in and electric vehicle owners need to manually change the setting for the home location to be able to charge at 12A.)

If you end up needing to install a new charging circuit but there is limited capacity available then a 240V/20A circuit is a decent introduction to Level 2 charging. (3.8kW gets you up to 14 miles of range per hour when charging.) The relevant Tesla NEMA power plug adapter is the NEMA 6-20.

If you set to 12A and there is an issue with the receptacle, the plug will sense the heat and turn down the charge rate. Or if something else is using the circuit and the voltage drops it will turn down the draw so the breaker hopefully doesn't trip.

 

[jcanoe]

If you set to 12A and there is an issue with the receptacle, the plug will sense the heat and turn down the charge rate. Or if something else is using the circuit and the voltage drops it will turn down the draw so the breaker hopefully doesn't trip.

At that point you are relying on consumer grade equipment to cover you a$$ when you choose to knowingly exceed the maximum safe amperage when charging.

 

[Mrbrock]

At that point you are relying on consumer grade equipment to cover you a$$ when you choose to knowingly exceed the maximum safe amperage when charging.

"Knowlingly"? 12A on a 15A circuit is not exceding any safe amperage when charging. It has already been limited from 15A for safety. If 10A was the maximum safe amperage then it would be code. 1/3 reduction in rated amperpage for charging, not 20%. I also do not believe there is anything in code that says recepttables have an expiration date so saying that charging on an older receptacle is knowingly exceding safety limits is a bit much. For example, a top of the line receptacle that is 20 years old but never been used is likely in better shape than one that is 2 years old but has things plugged and unplugged multiple times a day.

 

[jcanoe]

The OP is experiencing issues when charging, I'm just trying to help. Electrical components can wear out due to use, damage, corrosion and age. The low hanging fruit in this case includes checking all electrical connections and replacing any older receptacle. That is what I would tell anyone experiencing similar issues.

 

[stopcrazypp]

If you set to 12A and there is an issue with the receptacle, the plug will sense the heat and turn down the charge rate. Or if something else is using the circuit and the voltage drops it will turn down the draw so the breaker hopefully doesn't trip.

Yeah, in my experience, the Tesla automatically defaults to 12A and dials down the current if it detects an anomaly.