Mass Pike Service Plaza's getting 50kwh chargers this fall

The article does not report how many chargers will be at each location or what fees will be charged, but it's still progress.

http://www.bostonherald.com/business/automotive/2016/07/electric_vehicles_will_get_a_charge_along_mass_pike

You really want the Chargepoint 100 24 kwh quick chargers, not the 50kwh plus units. Try to keep your battery at a C/1 recharge rate, for the well being of the batteries. There's a good reason, VW and BMW are installing these ChargePoint 100 CCS units only. The batteries thermal protection is passive heat dissipation, not water cooled. So it needs to be recharged over an hour, not over 20 or 30 minutes when on a DC fast charger.

I'd like to see where in the VW e-Golf Manual it says that 24 kW charging stations are better than 50 kW charging stations (by the way, charging is expressed in units of kW and battery capacity is expressed in units of kWh).

Additionally, I'd like to see some data that shows 24 kW charging (actually around 22 kW on an e-Golf) has a real world impact on battery degredation as compared to 50 kW (actually about 44 kW on an e-Golf).

There's another good reason why BMW and VW are installing 24 kW charging stations: Money. The 24 kW stations are MUCH cheaper to purchase than 50 kW stations. Additionally, the station owners (who are NOT Chargepoint, by the way) can avoid additional electricity demand fees with a 24 kW stations that they would have to pay for with a 50 kW station. Remember, electricity is not free.

f1geek said:

I'd like to see where in the VW e-Golf Manual it says that 24 kW charging stations are better than 50 kW charging stations (by the way, charging is expressed in units of kW and battery capacity is expressed in units of kWh).

Additionally, I'd like to see some data that shows 24 kW charging (actually around 22 kW on an e-Golf) has a real world impact on battery degredation as compared to 50 kW (actually about 44 kW on an e-Golf).

There's another good reason why BMW and VW are installing 24 kW charging stations: Money. The 24 kW stations are MUCH cheaper to purchase than 50 kW stations. Additionally, the station owners (who are NOT Chargepoint, by the way) can avoid additional electricity demand fees with a 24 kW stations that they would have to pay for with a 50 kW station. Remember, electricity is not free.

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Read your owners manul, it's in there about recharging with quick chargers sparingly. Others here, Imura for one of them, has the backround to confirm that a C/1 recharging rate on the Vw batteries is acceptable and not heat generating. Since the VW battery is 24.2kwh, if you charge at less than 24 kw in bulk phase, that's supposedly acceptable.

Alternately, call VW Customer Care and ask them why you should quick charge sparingly. Then ask about a 24 kw charger as opposed to a 50kw charger.

I have recharged with the ChargePoint 100 24kw charger a few times. I've found that if they are located right next to the freeway... (Crevier BMW in Santa Ana, right off of the S55 and I-5) and I've been doing 60 mph plus, my battery is hot, and the charger limits the recharge rate to maybe 15 or 16 kw. If I get off the freeway 2 or 3 miles away and drive the rest of the way surface streets at 35-40 mph, with no jack rabbit starts, or stops, the car will then charge at 21.5 to 22kw rate immediately. YMMV, but if your batteries are hot, for what ever reason, hard discharge rates or hard regeneration cycles, they will slow down the recharge take rate.

I have read the owner's manual. It does not specify a quick charging speed, only how often to use quick charging. Considering you believe the Germans to be so good about specifying how to treat the car, because it's not listed in the manual, it doesn't matter.

I have never seen my charge rate limited and I've charged at 44 kW after driving at 60 mph for over an hour.

I have read that VW was so confident in the battery chemistry that they did not need to implement liquid cooling. What I'd like to see is empirical evidence that charging at 44 kW is harder on the battery than charging at 24 kW, taking into account the fact that either of these speeds will be rarely seen on a well maintained e-Golf. All I've heard from you is theory about charge rate, and while that theory makes sense, I'd like some proof, that's all. I'm guessing you don't have any proof.

f1geek said:

I have read the owner's manual. It does not specify a quick charging speed, only how often to use quick charging. Considering you believe the Germans to be so good about specifying how to treat the car, because it's not listed in the manual, it doesn't matter.

I have never seen my charge rate limited and I've charged at 44 kW after driving at 60 mph for over an hour.

I have read that VW was so confident in the battery chemistry that they did not need to implement liquid cooling. What I'd like to see is empirical evidence that charging at 44 kW is harder on the battery than charging at 24 kW, taking into account the fact that either of these speeds will be rarely seen on a well maintained e-Golf. All I've heard from you is theory about charge rate, and while that theory makes sense, I'd like some proof, that's all. I'm guessing you don't have any proof.

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I suggest you use Google and do some digging on Lithium Ion battery recharging times and recharging rates. Maybe Battery Universe can help you. Or better yet, go to Panasonic and LG, the battery manufacturers, since they warranty what they make, batteries, and ask them about recharging rates. Don't be so lazy, do a little digging on your own. Volkwagen is not in the battery making business. They just buy them to use them in their finished product.


You probably use all kinds of devices daily that you recharge that are run on lithium ion cells. Some have short charging times as a convenience, or due to low cost of replacement batteries. Those devices have very short charging times. Batteries that are very, very expensive have much longer slower recharging times, to prolong the lives of the batteries before replacement.

Contact the battery manufacturers. There are battery chemistries for performance, where cost doesn't matter, and there are batteries for utility uses, where battery life, and cost to replace batteries are more important than ability to recharge quickly Adding Cobalt to the lihium ion chemistry tends to be a battery life longevity chemistry, at the expense of ability to recharge quickly.

Volkswagen doesn't tell you a LOT of things.... they tend to deliberately keep owners of their cars in the dark, for good reason. Do your own research, form your own conclusions, but don't count on VW to ever tell you exactly how things are... far from it. They want you to get out of warranty and buy a new battery for $17,000 installed, due to misuse, or recharging or you not RTFM. Stupid customers are their best customers.

f1geek said:

I have read the owner's manual. It does not specify a quick charging speed, only how often to use quick charging. Considering you believe the Germans to be so good about specifying how to treat the car, because it's not listed in the manual, it doesn't matter.

I have never seen my charge rate limited and I've charged at 44 kW after driving at 60 mph for over an hour.

I have read that VW was so confident in the battery chemistry that they did not need to implement liquid cooling. What I'd like to see is empirical evidence that charging at 44 kW is harder on the battery than charging at 24 kW, taking into account the fact that either of these speeds will be rarely seen on a well maintained e-Golf. All I've heard from you is theory about charge rate, and while that theory makes sense, I'd like some proof, that's all. I'm guessing you don't have any proof.

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http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

Figure 1 shows the voltage and current signature as lithium-ion passes through the stages for constant current and topping charge. Full charge is reached when the current decreases to between 3 and 5 percent of the Ah rating.

Charge stages of lithium-ion
Figure 1: Charge stages of lithium-ion. Li-ion is fully charged when the current drops to a set level. In lieu of trickle charge, some chargers apply a topping charge when the voltage drops.
Courtesy of Cadex

The advised charge rate of an Energy Cell is between 0.5C and 1C; the complete charge time is about 2–3 hours. Manufacturers of these cells recommend charging at 0.8C or less to prolong battery life. Most Power Cells can take a higher charger. Charge efficiency is about 99 percent and the cell remains cool during charge.

To avoid confusion the the RC crowd, a 0.5C charge rate is a 50% State of charge acheived in 1 hour. A 1C charge rate is 100% Charged in an Hour. With that in mind... a 24 kw ChargePoint100 DC QuickCharger on a 24.2 kwh VW e-Golf battery, while not the best of 0.8C to 0.5C charge rate, is acceptable.

A 50 to 55 kwh/hour charge rate is a 2C charge rate, battery could be charged TWICE in one hour, or Once in 30 minutes... is a charge rate that exceeds current battery chemistry, heating rates, and charging rates, hence why VW recommends using 30 minute quick chargers SPARINGLY.


If you have any more questions, please direct them to Battery University.

You still haven't provided any empirical evidence that VW e-Golf batteries shouldn't be charged at 44 kW.

Tesla that sells a car with a 60 kWh battery in their Model S. Tesla lets the battery charge at 120kW (or maybe even 135 kW, depending on the charging station). That is 2C. According to your theoretical argument, Model S 60 batteries should be failing left and right. Do you have evidence of this happening?

Somehow it's ok for Tesla batteries (which are made by Panasonic, as are the batteries in the e-Golf) to charge at 2C. While you can argue Tesla doesn't understand how to manage batteries, I doubt you can prove it.

The issue isn't the rate per se, it's the heat. If you keep the temperature down you can safely charge batteries beyond the normal recommended rates. Since the Tesla batteries are actively cooled they can be charged at faster than recommended rates but since the VW batteries are passively cooled the batteries will incur damage from accelerated charging. How much damage and whether it matters to you is the issue, not whether it happens.

f1geek said:

You still haven't provided any empirical evidence that VW e-Golf batteries shouldn't be charged at 44 kW.

Tesla that sells a car with a 60 kWh battery in their Model S. Tesla lets the battery charge at 120kW (or maybe even 135 kW, depending on the charging station). That is 2C. According to your theoretical argument, Model S 60 batteries should be failing left and right. Do you have evidence of this happening?

Somehow it's ok for Tesla batteries (which are made by Panasonic, as are the batteries in the e-Golf) to charge at 2C. While you can argue Tesla doesn't understand how to manage batteries, I doubt you can prove it.

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Tell you what, why don't you provide empirical evidence that it doesn't happen. I don't have to prove anything on what will or what won't happen in an egolf with passive cooling of the battery pack. To you, or anyone else. Panasonic makes many different cell chemistries for different requirements. Vw's is not a performance model Battery with a fast recharging rate being good for longevity. Your clue is in the owners manual. read it.