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UMC Amperage Drop

bancroftc

Member
Sep 21, 2015
179
10
Austin, TX
This was a stupid mistake on my part, but I was surprised the car/charger didn't make note of it. I plugged in my UMC last night to charge and noticed the amps were only running around 16A @ 235V, when I have it set to 32A (50A circuit). I was only getting 12mi/hr charging when I usually get 24-25mi at 32A @ 240V. I thought perhaps the battery was hot, or maybe my electric system at home was experiencing an anomaly so it was metering itself, but a couple hours later there was no change.

I finally went out to the car to check on the charger - it was pulsing green as normal. Then i pulled on the charger handle and it came right out without me having to push the button. It wasn't plugged in all the way! Once I plugged it back in, it locked and then immediately ran up to normal charging at 32A.

This is more of PSA than anything. But I was surprised that the car even allowed it to charge without the charger being locked AND with an improper connection.
 

mikeash

Active Member
Oct 26, 2014
1,105
699
Fairfax, VA, USA
It's definitely not supposed to charge without being locked in. Every so often I don't quite push mine in all the way, and it gives me an orange ring and tells me to check the cable, and refuses to charge until I push it in the rest of the way and it locks. It sounds like you either managed to find a position where it looked locked from the car's perspective but didn't engage, or hit some sort of software bug. Either way, might be worth contacting Tesla. If you tell them when it happened they might be able to look at the logs to see what the car was doing and maybe see if something is wrong.
 

bancroftc

Member
Sep 21, 2015
179
10
Austin, TX
Yeah I was under the impression you would get a charging fault if not properly connected. That's why I was looking for other non-plug related issues. Live and learn I suppose. My car and UMC are relatively new, so the charging plug/port have some resistance. I would imagine that would improve over time to make it easier plugging in. Not that it's hard to plug in, I just have to be deliberate about it. Which apparently I wasn't last night.
 

FlasherZ

Sig Model S + Sig Model X + Model 3 Resv
Jun 21, 2012
7,024
1,013
The car will charge at 16A when it detects proper ground, a good pilot signal, and has steady voltage from the supply pins but is not locked in place, it's not completely unsafe because of the failsafe checks (if any of those 4 are intermittent, then it goes red and you have to reconnect the car). That's why you have the orange ring.
 

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