How is the range calculated

[Tuningin]

So we are told that the car has a 24.2 kw battery pack. I'm now at over 1000 miles on the car and I'm still scratching my head about why the math never pencils out.

I average 4.9 miles per KW so

24.2 x 4.9 = 118 mile range.

However, the after a 38 mile trip ( at 4.9 miles/kw) the car shows a 66 mile range left

38+66= 104 mile range


Anyone know why there is a discrepancy?

 

[cove3]

Only 21.1 of the 24.2 is usable. The rest is off limits as regards moving the car, this to conserve battery life. So when the fuel gauge reads full, you have 21.1 kwh to use for driving. 21.1 should be used for all calculations

I thought I was getting only 4.0 around town with temps in the 30's, but I'm monitoring it set on since last charge, and it abruptly started showing 5.1, so I'm assuming the calculation somehow average past driving over who knows what period. Anyway, I've only got 90 miles on the car and am still learning how things work

Ron

 

[GadgetGav]

You're both doing better than me. My data shows between 3 & 4 miles / kWh, mostly around 3.5
That's New England winters for you I suppose...

 

[Tuningin]

Only 21.1 of the 24.2 is usable. The rest is off limits as regards moving the car, this to conserve battery life. So when the fuel gauge reads full, you have 21.1 kwh to use for driving. 21.1 should be used for all calculations

I'm only getting 4.0 around town with temps in the 30's

Ron

Thanks for the info. I didn't realize that VW had already reduced the max charge to save battery life. I've on weekends reduced charge to 80% to do the same, but this is redundant.

As far as how I'm getting the higher mile/kw. I do use the climate departure feature to warm the car up off of the grid before I start driving to help with the mile/kw. I use B instead of D, plus the traffic keeps me at 35 mph average. But I think that being 25-30 degrees warmer here makes the bigger difference.

 

[cove3]

I'm not sure it's redundant. I think the 40-60% level is based on the 21.1, but I've seen no authority like VW or Panasonic say this as being recommended to maximize battery life, so it might be hearsay. The only thing the owners manual says is to not charge over 98%, not to charge using CCS consecutively, not to charge when the battery is full, and not to let the battery be at a low state of charge below 3% for an extended period of non-use but rather at 40-60%, without defining what extended is

Ron

 

[Tuningin]

I'm not sure it's redundant. I think the 40-60% level is based on the 21.1, but I've seen no authority like VW or Panasonic say this as being recommended to maximize battery life, so it might be hearsay. The only thing the owners manual says is to not charge over 98%, not to charge using CCS consecutively, not to charge when the battery is full, and not to let the battery be at a low state of charge for an extended period, without defining what extended is

Ron

I only know what I know based off of whitepapers and don't have firsthand knowledge.

From what I've read, 40-60% of total battery capacity is the idea range to maximize battery life. Cycling above 80%, there is a pronounced loss in number of charging cycles. This is likely subject to change as battery technology improves. The eGolf Li battery has the Nickel-Manganese-Colbalt which is supposedly more durable than the types of LiIon batteries used on the Leaf and Volts plus other older EV's when these papers were written.

If VW is programming in to cut off at 21.1kw of 24.2 battery capacity, it means at full charge we are doing a 87% cycle. Might not be a bad idea to reduce max to 90% on Car-net to stay below the 80% threshold. At 90% of 21.1kw we'd charge to 19 kw which is 78.5% of the battery capacity of 24.2kw.

If we want to stay below the 60% of 24.2kw threshold this would be 14.5kw, then it would be 68.9% of 21.1kw. So on Carnet, 60-70% keeps the car in the ideal area. This is keeping in mind that mathematically 40% of 24.2 equates to 45.8% of 21.1kw, which we don't want to fall below.

 

[f1geek]

I don't mean any disrespect, but I hope you are joking about not fully charging the battery. If fully charging the battery kills it, then VW is going to be either going to be replacing a lot of batteries under warranty and/or be hit with a lot of lawsuits. It makes no sense that the end user would have to worry about overcharging the battery - the charging is computer controlled, no?

I want my full 83 miles (more or less per driving situation, I know) every day in case I need it. There is no way in hell that I won't fully charge the battery provided there is enough time to do so - anything less is ludicrous.

 

[Tuningin]

I don't mean any disrespect, but I hope you are joking about not fully charging the battery. If fully charging the battery kills it, then VW is going to be either going to be replacing a lot of batteries under warranty and/or be hit with a lot of lawsuits. It makes no sense that the end user would have to worry about overcharging the battery - the charging is computer controlled, no?

I want my full 83 miles (more or less per driving situation, I know) every day in case I need it. There is no way in hell that I won't fully charge the battery provided there is enough time to do so - anything less is ludicrous.

Who said anything about killing the battery? Scientifically they correlate level of charge cycles with battery life. If you need the range that it would be foolish to not to charge it full. Some people don't drive that far or can charge at work. Some people want their $10k+ batteries to last 200k miles while others don't care because they're on a 3 year lease. If you don't care for the battery to last beyond warranty, then this information would not be relevant. Since this is my car used only to commute for work, I'd like it to last as long as possible. It's your choice what you want to do with your car.

 

[cove3]

Here are 3 useful links I found on how to prolong the life and capacity of the battery
Key does seem to be to try and keep it in the 40-80% range, don't overcharge or undercharge, avoid excess CCS charging, etc. Getting Car-net charge level scheduling to work seems important in achieving this

http://www.plugincars.com/eight-tips-extend-battery-life-your-electric-car-107938.html
http://www.cartrade.com/blog/2014/car-tips-and-advice/tips-to-extend-battery-life-of-your-electric-car-550.html
http://www.autoblog.com/2011/10/05/eight-tips-to-extend-electric-vehicle-battery-life/

Ron

 

[GadgetGav]

This is the main reason that this is my first leased car, not bought. It's early days for VW in EVs and while I'm happy to be an early adopter, I don't want to be dealing with issues in 5, 6 or 7 years time. I'm sure by the time my 3 year lease is up the EV market will have changed significantly. VW will have learned a lot from the eGolf (and the eUP in Europe), battery technology and charging technology will have progressed, the affordable Tesla will be pushing everyone else to do better. I expect to still be driving an EV in 7 years time, just not this one in particular, so I'm not going to worry too much about nursing the battery to maximum lifespan.

 

[Tuningin]

This is the main reason that this is my first leased car, not bought. It's early days for VW in EVs and while I'm happy to be an early adopter, I don't want to be dealing with issues in 5, 6 or 7 years time. I'm sure by the time my 3 year lease is up the EV market will have changed significantly. VW will have learned a lot from the eGolf (and the eUP in Europe), battery technology and charging technology will have progressed, the affordable Tesla will be pushing everyone else to do better. I expect to still be driving an EV in 7 years time, just not this one in particular, so I'm not going to worry too much about nursing the battery to maximum lifespan.

I've leased it also, since it gives me the option to opt out at 3 years. I may or may not choose to buy out the lease. I've leased cars in the past where the leasing company decided that they misjudged residual values and offered a significantly lower purchase price than what was on contract. If it makes sense to buy the car, I may do so or I might trade for a different EV.

I'm not nursing the battery, but I am adjusting the charge schedule accordingly since my use of the car is very routine. The only purpose of this car is to get me to work and back so I know how much range I need and when I need it. Like I said, if changing the charge level is inconsequential and extends the battery life, makes sense to do it. If it were my only car, yes I'd max the charge every time.

I'm not holding my breath on the affordable Tesla in 3 year. As much as I want that to happen, I'll believe it when I see it. Well I should correct myself, I don't believe that Elan will be able to not take a loss on a car with a 200 mile range that he's going to sell for $35k without incentives. I like the guy's vision, but he has made a lot of claims that never came to be. I bet it'll be more like 10 years before we see him get battery prices down that low.

 

[bingtamers]

I completely agree about Elon Musk's claims and the probable release date of his Model 3. Even the Model X is only in very limited release and it's a couple of years late already.

But there are other cars coming out that offer good range at a low cost. I see 2016 Chevy Volts on my commute to work every morning. They look pretty sleek. It would be perfect for me to have 53 miles EV range for the daily commute but the option to drive farther on weekends or whenever I have to go somewhere off the beaten path.

I'm not a Chevy shill. I've leased a 2016 eGolf SE (silver) and like it a lot so far. I just think that in three years we will have a lot of excellent options, including maybe an eGolf that goes 200 miles on a charge.

I wish VW had a plan to upgrade our batteries (at our cost) in three years. I would probably buy the car if there were an upgrade path, but so far I haven't run across any information along those lines.

 

[JoulesThief]

I completely agree about Elon Musk's claims and the probable release date of his Model 3. Even the Model X is only in very limited release and it's a couple of years late already.

But there are other cars coming out that offer good range at a low cost. I see 2016 Chevy Volts on my commute to work every morning. They look pretty sleek. It would be perfect for me to have 53 miles EV range for the daily commute but the option to drive farther on weekends or whenever I have to go somewhere off the beaten path.

I'm not a Chevy shill. I've leased a 2016 eGolf SE (silver) and like it a lot so far. I just think that in three years we will have a lot of excellent options, including maybe an eGolf that goes 200 miles on a charge.

I wish VW had a plan to upgrade our batteries (at our cost) in three years. I would probably buy the car if there were an upgrade path, but so far I haven't run across any information along those lines.

If the battery chemistry improves such that they can reliably get more mah per cell, in the same space, perhaps, like Nissan, 30 kw batteries may become reality, in the same form factor. Pretty sure VW is going to try to charge a pretty penny for it, with the increased range. One thing for certain, 2nd generation VW designs, from a reliability stand point, in the past, have been, in my observation, very desirable long term keeper vehicles. Just remember, though, the past is not a prediction of the future. I am thinking VW will try to get a 4 year or more run out of this generation Golf.

So far, I too really like the cost per mile of this little VW. For around town, or going through the canyons to the Pacific Ocean, it is one fun little car. I am thinking a trip on Mulholland Dr. is in order some day.