240 miles on a charge - Good but weird battery behavior

[dhrivnak]

My 2008 1.5 battery has always been a bit on the low side with about 177 miles on a standard charge and a CAC of 144. Since having the car I average about one range charge per month and have run the same tire (brand) for the past 16,000 miles.

Then this summer my range crept up to 180 miles and my CAC increased to 148. After being steady at 144 for more than a year. I had a 200+ mile trip yesterday so decided to fully test the range for the first time and see if the range increase was for real. I did a best ever of 240 miles 25 miles farther than I have ever don on a single charge. And another weird quirk is my power consumption for this same trip I have done a dozen times was a record low. Previously on the way to Knoxville the lowest power use has been 221 watts/mile but yesterday it was 201. I have driven several times on a similar day with no wind and comfortable temperatures. The road normally has light traffic and I normally set the cruise on 50 which is the limit on that road.

Has anyone else seen their range increase? In plotting my standard ideal miles I now have a slight positive trend over the last 19,000 miles.

 

[wiztecy]

Odd thing is that your ideal miles seem high for your CAC value. I've had 3 packs and monitored their CAC value closely. The previous pack had a CAC of 146.5 and only took a std mode charge of 174 tops. I have my "healthy" pack now that's still climbing in CAC. I'm at 154.87 CAC and it charges to 184 ideal miles. My "original" pack charged up to 182 ideal miles and had 148.50 CAC. I may have to take the Roadster on a long drive to see if the "Tesla Recalculation Magic" as per Tesla happens. I noticed that my pack keeps recalculating CAC and climbs as long as I keep the SOC above 65-70% SOC. Mostly you have to do a std. mode charge to bring things up and then that appears to trigger a re-calculation. If I let the Roadster sit @ 60% SOC it won't recalculate nor climb the CAC.

 

[hcsharp]

The difference is due to the fact that you're now traveling with The CAN instead of the old Tesla J1772 adapter so you're lighter and quicker and your trunk has extra room for a change.:biggrin:

Seriously, how much wear do you have on your tires compared to the last trip? Same tire pressures? And did you encounter any rain on either trip? Have you had an alignment done? I find that all these things affect my range.

 

[dhrivnak]

It is the same tires and pressure but i am now nearly bald on the rears. I agree rain does make a difference sometimes a large one. But the last few have been rain free.

Also i had been driving gently so the range was higher than the ideal range. A rare but not unheard of situation.

 

[thefortunes]

Based on your Trip display, your average speed is actually 40mph, not 50mph. Is it possible that you oops'd on your cruise set (or did you have some significant time at lower speeds to offset the 50mph on the bulk of the trip)?


207 Wh/mi is certainly reasonable for 40mph, especially if you drove "gently" and there was no wind.

 

[dhrivnak]

No unfortunately as to setting the cruise at 40, as there are a few red lights on the route and I have several miles of slow intown driving on both ends of the trip. A minute at a stop light really pulls down the average speed.

 

[thefortunes]

No unfortunately as to setting the cruise at 40, as there are a few red lights on the route and I have several miles of slow intown driving on both ends of the trip. A minute at a stop light really pulls down the average speed.

There's something else affecting the data here.

Even if you had 10 miles at each end of the trip and averaged 20 mph for those 20 miles, and stopped for 3 lights (sitting for 10 minutes), you would still only use 5 hours and 35 minutes for the 240 miles - not the 5 hours 59 minutes you did use per the VDS tripmeter. Is it possible you didn't reset the tripmeter and had some in-town driving already on it at a low Wh/mi?

 

[dhrivnak]

I did reset the trip on the beginning. To get on the highway there is at least a dozen lights and a half dozen stop signs on my end of town and a good 5 miles of 30 mph driving to get on the highway. Then on the 80 mile stretch of highway there are 4 lights and then I get into Knoxville with a number of lights, stop signs and circling for a parking space. Someone also hit a light pole knocking down the pwoer lines so the road was closed and after setting for 5 minutes I had detour around. But with the exception of the accident I take the same route out of town and to Knoxville.

 

[dhrivnak]

I just made another Knoxville run with almost a record in the wrong direction. While in September my energy usage was 201 watts/mile yesterday my energy was 286 watts/mile. We had light rain and I had to run the heat some but I was surprised at the 40% hit to range. To further frustrate matters on the way home I was cutting it VERY close (3 miles to spare) so I detoured 4 miles for a charger only to find both Blink chargers on the blitz. Now I could not make it home so I had to detour farther to find another Blink charger needing repair. Fortunately I found a very nice Nissan dealer and ended up getting home 4 hours late due to time lost in detouring, trouble shooting broken chargers and then extra charge time to cover the detour.

I do have new tires on the car which may have been part of the extra energy use. I will have to try again in the spring when it is again warm.

 

[Doug_G]

The Roadster's cabin heater sucks power. Use the seat heaters instead, and wear a jacket. Also continuous rain does have a significant effect. The two things together are probably what gave you trouble, though I'll bet the cabin heat was the bigger issue. You probably would have made it with the heat off.

Tip: when running without cabin heat on the highway, a lot of cold air comes into the cabin. To reduce this, turn on recirculation, direct the air to the vents, and then close the vents! You'll still get enough airflow to keep the windshield clear, but you won't be nearly as cold. If you have to slow down for a town put a little heat on the windshield until you're back to highway speeds again.

 

[Rik]

So I'm a newbie and allowed to ask at least 1 silly question... why is dhrivnak's september estimated range greater than ideal range? I love to see the high numbers, especially on the older models so I am not complaining

 

[Pantera Dude]

So I'm a newbie and allowed to ask at least 1 silly question... why is dhrivnak's september estimated range greater than ideal range? I love to see the high numbers, especially on the older models so I am not complaining

I'm guessing that he has been driving quite conservatively to get that number? I on the other hand would probably not come close to that high number.:biggrin:

 

[dhrivnak]

So I'm a newbie and allowed to ask at least 1 silly question... why is dhrivnak's september estimated range greater than ideal range? I love to see the high numbers, especially on the older models so I am not complaining

Your range is based ont eh average power used over the last 40 miles. Since I was going for maximum range I was not hit rodding it. also Kingsport is at a lower elevation than Blountville so the last 25 miles was a gentle downhill adding to the greater range. While not often I can get better than the ideal range, it just is not as much fun that way.