Well, reading back a bit in this thread, and based on my very limited knowledge about this stuff, it looks like I have a real problem with my battery. Here's the background. Any help / suggestions greatly appreciated.
First, I must mention that the Green Machine lives in a plane hangar about 30 miles from home, and the plane itself is out of service for an extended period, so it gets fairly limited service. I drove it San Diego to Santa Barbara and back back in August, and it seemed fine at the time, but as I approached Santa Barbara the screen said it had about 30 miles left, when it suddenly lost power. I managed to get off the freeway, and parked, but after I turned it off and back on, it now gave warnings about having a dangerously low state of charge. I got towed to the local Tesla service center, and left it plugged in there overnight, and everything seemed fine. Drove back later that week with a charging stop at a hotel in LA somewhere, put it back in the hangar with a low but non-dangerous state of charge, plugged in, and forgot it for a month or so. When I next went out, intending to take it for a drive, I discovered that it had never really charged up. It looks like either the GFCI had tripped or maybe a circuit breaker tripped, the GFCI head on the cable needs to be re-set every time either way. I made sure it was charging before I left. Came back a month or so later to the same situation, so I figured it must have tripped the circuit breaker when someone else on the same circuit must have used a high-current device or something. I dropped the charge current to 12A, came back the next day and it was still charging (standard mode), but that gave me confidence.
So today, beautiful weather, decided to take it for a drive. Everything looked fine at the start, the only warning was the ever-present TPMS error. But it felt sluggish. I drove it about 10 miles east, then took a back road up a long steep hill (to Crest, for anyone local to San Diego). As I started to go up the hill at full go-pedal, the car slowed to about 50mph, and the power meter was reading about 50kW. Gradually that dropped to 40kW and 40mph, so as soon as I could do a u-turn I did. Going back down the hill, if I floored it, I could see 100kW on the meter for a short time. I headed back to the hangar just in case. Experimenting on a safe, flat road, I found that starting from stopped and planting my foot, the power meter peaked at 1bout 100kW, but over a period of just a few seconds dropped to 75, 70, and flattened at about 60-65kW.
I parked and took photos of all the various battery-related screens, see below. I suspect that either the battery is seriously out of balance, or some cells are sour, or both. :-( But I'm not good at diagnosing stuff like this, hence asking for opinions. In the meantime I put it back on to do a range charge over night, and will go out again tomorrow to drive it down off max charge, and can report back. From reading back I can see that the CAC is terrible, and it's out of balance, but maybe others have other insights too.
Here are the photos:
First, I must mention that the Green Machine lives in a plane hangar about 30 miles from home, and the plane itself is out of service for an extended period, so it gets fairly limited service. I drove it San Diego to Santa Barbara and back back in August, and it seemed fine at the time, but as I approached Santa Barbara the screen said it had about 30 miles left, when it suddenly lost power. I managed to get off the freeway, and parked, but after I turned it off and back on, it now gave warnings about having a dangerously low state of charge. I got towed to the local Tesla service center, and left it plugged in there overnight, and everything seemed fine. Drove back later that week with a charging stop at a hotel in LA somewhere, put it back in the hangar with a low but non-dangerous state of charge, plugged in, and forgot it for a month or so. When I next went out, intending to take it for a drive, I discovered that it had never really charged up. It looks like either the GFCI had tripped or maybe a circuit breaker tripped, the GFCI head on the cable needs to be re-set every time either way. I made sure it was charging before I left. Came back a month or so later to the same situation, so I figured it must have tripped the circuit breaker when someone else on the same circuit must have used a high-current device or something. I dropped the charge current to 12A, came back the next day and it was still charging (standard mode), but that gave me confidence.
So today, beautiful weather, decided to take it for a drive. Everything looked fine at the start, the only warning was the ever-present TPMS error. But it felt sluggish. I drove it about 10 miles east, then took a back road up a long steep hill (to Crest, for anyone local to San Diego). As I started to go up the hill at full go-pedal, the car slowed to about 50mph, and the power meter was reading about 50kW. Gradually that dropped to 40kW and 40mph, so as soon as I could do a u-turn I did. Going back down the hill, if I floored it, I could see 100kW on the meter for a short time. I headed back to the hangar just in case. Experimenting on a safe, flat road, I found that starting from stopped and planting my foot, the power meter peaked at 1bout 100kW, but over a period of just a few seconds dropped to 75, 70, and flattened at about 60-65kW.
I parked and took photos of all the various battery-related screens, see below. I suspect that either the battery is seriously out of balance, or some cells are sour, or both. :-( But I'm not good at diagnosing stuff like this, hence asking for opinions. In the meantime I put it back on to do a range charge over night, and will go out again tomorrow to drive it down off max charge, and can report back. From reading back I can see that the CAC is terrible, and it's out of balance, but maybe others have other insights too.
Here are the photos:
