I have put a 50amp breaker in the garage, 240 outlet, the onboard is set to 40amp. I used to get 28, 29 miles per hour charging, but the last few days its only been 12-14. Am I doing something wrong? Software is still the .42 version. And the Tesla App won’t always connect to my car. Thanks in advance
Derek Kessler
Active Member
Check the breaker and the outlet. Sounds like one of the two hot leads has disconnected, so now you're getting 40A at 120V.
It doesn’t work like this. It gets 240 volts across the two hots. If one is disconnnect then there will be no power at all.
As far as the original question goes, I would look at the amount of power the far says that it’s getting rather than miles per hour. Is it showing that you’re charging at 40 amps? Is it possible that somehow it got turned down for that location?
What does the charging screen in the car say? If it’s less than 40A, set it back to 40A and try again. If the amps drop again, then you have a problem. The car drops amps by 25% when it senses a voltage drop.
Actually, I take this back. Sort of. When I posted that I was thinking of the HPWC, which doesn’t even have a neutral connection and will charge at 240V or nothing. However, the OP didn’t say what he was using to charge with. If he’s just using a 14-50 outlet with the mobile connector then I don’t know how that would handle the loss of one of the hots. The mobile connector can charge at 120 or 240 volts, and a 14-50 outlet does include the neutral, but I don’t know if the neutral is even wired through the mobile connector’s 14-50 plug or if it would use it to charge at 120V if it only had one hot. So I guess this might be possible. Maybe.
Car’s display and my app (when it wants to respond) both say I am getting 40A. I am not personally able to check on the leads issue. (I don’t want to fry). The charge speed has gotten up to 18 miles after a few hours
I am using the mobile connector with the 14-50 outlet. It was doing great until I plugged it in today.
It was 30 when I plugged in today, I moved it to 40, where I thought it was before.
Derek Kessler
Active Member
Something almost definitely finicky with the outlet or breaker wiring. If you can flip the breaker then it will be perfectly safe to check the receptacle's wiring without risk of frying. For most setups it's easy access (a few screws) and easy wiring (leads into contacts, screwed down tightly). If you're not comfortable with it, I understand, but it's not difficult or unsafe.
You can also pick up a cheap voltage tester and stick it in the slots to check for current. Both the left and right should have current.
You can also pick up a cheap voltage tester and stick it in the slots to check for current. Both the left and right should have current.
David99
Active Member
Make sure the plug is really pushed in all the way. If it's half way it will charge but at a reduce rate
Derek Kessler
Active Member
There is always a ramp up as it tests the available amperage, but it's on the order of seconds.
Derek Kessler
Active Member
Current running through the wiring and outlet will make it warm. Might be just that loose in the outlet that the heat-driven expansion was enough to reconnect a loose lead. I'd still investigate — loose wiring with that much voltage and amperage behind it can be dangerous.
