Fast Charging shortens life of battery, if done regularly.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Joined
Oct 5, 2015
Messages
2,576
Seems dealerships are aware of level 3 Fast Charging not being the best for battery life on the e-Golf.

http://www.volkswagenvannuys.com/blog/how-to-charge-e-golf/

"It’s not recommended to use DC Fast Charging all the time because it can shorten the lifespan of the e-Golf’s battery."

I am wondering if anyone has a list of all the what I call Level 3.1 ChargePoint 100 24 kw chargers are located, at least in California. I'd like to know, so I can avoid the full Level 3.2 50 kwh jobs, and keep the charging down to a C/1hr rate of charge or slower.

Edited: Because I'm not an EE or know the difference between kw and kwh. Correct term for chargers is kw.
 
JT,

There are no 24 kWh chargers, but there are 24 kW chargers. kWh is a unit of energy. kW is a unit of power. Batteries are rated in kWh and chargers are rated in kW.

Also, they are not technically Level 3, but Level 2 DC (according to the SAE specification).

From what I can tell, Chargepoint is actively selling the IES Synergy KeyWatt 24 kW units (orange box with Chargepoint graphics) for any location and BMW also distributes the same device (blue box with BMW graphics) to BMW dealers. Also, with an e-Golf, about the maximum charge rate you can get is ~22 kW as these units are limited to 62 amps output current and I think the max voltage the e-Golf will take is about 355 volts (355V x 62 A = 22,000 W or 22 kW).

Look at www.plugshare.com, filter your results for DC CCS stations and the Chargepoint network and most of what you see will be the 24 kW units. You could also visit the Chargepoint website and look at the station map, again filtering for DCFC CCS stations and the Chargepoint network.

Chargepoint also has the 44 kW Veefil (125 A max current output) dual DCFC units out in the field, but I don't see too many of those as compared to the KeyWatt units.

While the 24 kW stations do take longer to charge, if you don't show up with a completely depleted battery, the difference in charging time won't be too great to get to 90% state of charge. I have used many of the 24 kW stations and they generally work well, though I have seen some that are on the fritz often - I don't know if the station owner did something wrong with the install or it the units themselves have spotty quality control.

Happy charging!
 
I see those Level 2 DC chargers that are 24 kw rated as being able to put about 3.3kw into my e-Golf battery every 10 minutes, if the battery is in a 40 to 50% SOC. The first 90 seconds are kind of wasted with the unit sorting out the pulse signal and what the battery is capable of taking on. Usually starts in 30 seconds with about 6 kw at about 320V, and within another minute, it will show about 20.6 kw in the read out.

I visited a couple of them today at BMW dealerships, and I am quite happy with the way they charge. The battery truly seems to get full on them, and the taper rate on the charging is over a much longer amount of time. A 4.5 kw charging rate readout is about 97 or 98% SOC on the gas gauge. I am pooped. 328 miles today on the e-Golf. North San Fernando Valley to Mexico, at the San Ysidro Border, and then back, in one day. LOVED the HOV lane where the I-805 and I-5 merge together in North San Diego County at 5:15 PM. Saved a ton of time passing all the ICE'ers, first time I remembered I even had the stickers on my bumper.

These units, IMHO, were engineered for e-golf and BMW I3 sized traction batteries. It also explains why VW and BMW both co underwrote the install of these units on the East and West Coast. We will see how the battery degradation goes with these level 2 DC chargers.

Where did you see this spec for Level 2 DC Chargers listed? A link?
 
Good job on using the DCFC stations! It would be nice if VW offered some information about battery degradation with DCFC usage, but they don't seem to like to give out too much information about their cars....

I got the info from the Chargepoint website. This is the datasheet for what they call the Express 100 (for 100 miles of range per hour).

http://www.chargepoint.com/files/datasheets/ds-cpe100.pdf

The Express 100 station works well with the current models of i3 and e-Golf, but I just read that the 2017 i3 will have a 33 kWh battery pack. The advertising will now need to change because it won't be possible to get an 80% charge in 20-30 minutes with a larger battery pack - it will take 30-40 minutes for the new i3.

Happy DCFC'ing!
 
http://www.torquenews.com/1/why-vw-recommends-using-vw-egolf-battery-sparingly-when-it-comes-fast-charging

"When it comes to e-Golf fast-charging VW has a statement in the owner's manual that every e-Golf driver needs to pay close attention.

VW's statement about DCFC reads: “Requires charging at select DC fast-charging stations. Frequent and consecutive high-voltage charging (including DC charging) can permanently decrease the capacity of the high-voltage battery. See your Owner’s Manual for details." There really isn't much more than that in the big manual. And the warranty doesn't apply if the owners manual is not followed.

Ronald B. Vlack explains in a VW e-Golf group on Facebook.

"The e-Golf battery has no cooling system like Tesla, i3 etc. Only passive cooling to save cost and weight. High speed charging generates lots of heat and heat is the enemy of BEV batteries. That's probably why VW recommends using sparingly and not consecutively. When they announced the change to no cooling, they said their tests showed it wasn't needed, but didn't indicate if the tests included some mix of high speed charging.

"The battery warranty does say it doesn't apply if guidelines described in the users manual are not followed. These guidelines are pretty specific, so assuming VW logs battery/charge/temp data, they do have an out on 8 year 70% coverage," Vlack explains.


Says it all...There is no way to modulate DCQC charge rate from the EVSE, it's up to the car and EVSE to negotiate. Higher speed means more heat == shorter battery life due to Lithium dendrites: https://en.wikipedia.org/wiki/Lithium-ion_battery#Degradation

.02
 
I contacted VW of America to find out more information about DCFC recommendations. Here is the email response I got back:


"Thank you for your patience while I got back to you. I’ve had the chance to research the charging options for your e-Golf with my product specialist team and I am happy to share what we found.
DC charging pushes power directly into the battery. This allows it to recharge more quickly than AC charging but, because the energy isn’t as controlled, it may try to push more power than is needed to some of the cells and ultimately may decrease their charge capacity.
We do not have a specific recommendation for how many DC charges is too many – just that it should be used less frequently than AC charging. Because AC charging is more controlled, it charges the individual battery cells until they are full and no further. While this is slower than DC charging, it can serve to help re-balance the charge in the cells. This helps the cell’s longevity, which is why we recommend doing an AC charge after a DC charge."

Again, VW won't give out specific information about their research into DCFC-related battery degradation.

You can decide what you want to do in relation to the battery warranty, but VW is not prohibiting DCFC usage.

I generally use DCFC once to be able to travel over 90 miles in a day, charge overnight and then use it again for the trip home the next day or the day after. This is a trip I take no more than 4 times a year. I don't view this as excessive, but each driver will have to weight their own usage appropriately.
 
f1geek said:
I contacted VW of America to find out more information about DCFC recommendations. Here is the email response I got back:


"Thank you for your patience while I got back to you. I’ve had the chance to research the charging options for your e-Golf with my product specialist team and I am happy to share what we found.
DC charging pushes power directly into the battery. This allows it to recharge more quickly than AC charging but, because the energy isn’t as controlled, it may try to push more power than is needed to some of the cells and ultimately may decrease their charge capacity.
We do not have a specific recommendation for how many DC charges is too many – just that it should be used less frequently than AC charging. Because AC charging is more controlled, it charges the individual battery cells until they are full and no further. While this is slower than DC charging, it can serve to help re-balance the charge in the cells. This helps the cell’s longevity, which is why we recommend doing an AC charge after a DC charge."

Again, VW won't give out specific information about their research into DCFC-related battery degradation.

You can decide what you want to do in relation to the battery warranty, but VW is not prohibiting DCFC usage.

I generally use DCFC once to be able to travel over 90 miles in a day, charge overnight and then use it again for the trip home the next day or the day after. This is a trip I take no more than 4 times a year. I don't view this as excessive, but each driver will have to weight their own usage appropriately.
The language in their e-mail makes it sound like you should not DC charge to 100%, which is actually a good tip for another reason - it slows down. So, you might as well start driving again because the benefit of fast charging is already lost by the time the battery reaches about 90%.
 
miimura said:
f1geek said:
I contacted VW of America to find out more information about DCFC recommendations. Here is the email response I got back:


"Thank you for your patience while I got back to you. I’ve had the chance to research the charging options for your e-Golf with my product specialist team and I am happy to share what we found.
DC charging pushes power directly into the battery. This allows it to recharge more quickly than AC charging but, because the energy isn’t as controlled, it may try to push more power than is needed to some of the cells and ultimately may decrease their charge capacity.
We do not have a specific recommendation for how many DC charges is too many – just that it should be used less frequently than AC charging. Because AC charging is more controlled, it charges the individual battery cells until they are full and no further. While this is slower than DC charging, it can serve to help re-balance the charge in the cells. This helps the cell’s longevity, which is why we recommend doing an AC charge after a DC charge."

Again, VW won't give out specific information about their research into DCFC-related battery degradation.

You can decide what you want to do in relation to the battery warranty, but VW is not prohibiting DCFC usage.

I generally use DCFC once to be able to travel over 90 miles in a day, charge overnight and then use it again for the trip home the next day or the day after. This is a trip I take no more than 4 times a year. I don't view this as excessive, but each driver will have to weight their own usage appropriately.
The language in their e-mail makes it sound like you should not DC charge to 100%, which is actually a good tip for another reason - it slows down. So, you might as well start driving again because the benefit of fast charging is already lost by the time the battery reaches about 90%.

I have DC fast charged a few times, once again on this trip on May 3rd. The device showed I charged 29 minutes and took on 17.3 kwh. I immediately followed this DC charge with a balancing/equalizing charge at a Level 2 208V 30 amp charger that took another 35 minutes to fully 100% charge my battery pack.

What I have noticed is that using a 20 -30 minute recharge, for reasons unknown, to be a battery recharge that has a relatively few percentage shorter distance range on a recharge. This has been consistent, about 5 to 7% shorter range. It's as if the battery gets a false "full charge" reading.

What I notice with the ChargePoint 100 level 2 DC fast charger at 20 .6 kw is an almost full 98% SOC when the amps drop down to about a 4 Kw rate on the charger. The e-Golf does not seem to lose range between charges on this type of charge.

Screenshot%202016-05-06%20at%203.25.16%20AM_zpsgi5o53rp.png


Screenshot_2016-05-03-22-45-16_zpsgffdiexh.png



Screenshot_2016-05-03-22-44-57_zpsoxqnbnkv.png



Screenshot_2016-05-03-22-44-16_zpszygaf2je.png


It should be noted that I immediately followed with a full 100% Level 2 recharge at 240V AC and 30 amps the next morning, after letting the battery cool off overnight.

The drive performed sole purpose was to test extended range driving that can be one in one day, without an overnight excursion, which would allow a full Level 2 recharge and a hotel or motel overnight.

I left around 9:20 am for San Ysidro CA, and the Mexican Border of Tijuana, and back, and arrived home late that night, around 10 pm. Very, very long day of driving with all the recharging involved. Charge stations dictated when I stopped, not how low I could run the battery, although I did go 98 miles from Santa Ana to Chula Vista on one charge, and I did use a level 3 charger there, and did follow with an AC equalize charge also, per VW recommendations, every other charge being AC. I did use the HOV lane at 5 o'clock rush hour traffic going north on Interstate 805 and where it merged with Interstate 5, the CA white HOV lane sticker finally paying for itself.

I did pace myself in the slow lane, as long as possible, at a self imposed 55 mph to extend my range and minimize my recharge time between battery charging sessions.

The drive above was performed pretty much for scientific purposes only.

I feel the ChargePoint 100 24 kw level 2 DC rechargers are easier on the battery, but I still would do my very best to follow VW's instructions with Level 2 208-240VAC recharges at 30 amps to a full SOC, every other recharge, and not deviating from their recommendations.

I'd still use ChargePoint 100 Level 2 mid range chargers "sparingly" as VW suggests, instead preferring home overnight charging with my e-Motorwerks Juicebox 40 Pro at 240V and 30 amps, if at all possible. Overnights at lodging facilities or RV parks with 208V or 240V at 30 amps are also very good choices.

* An important footnote, I own my 2015 SEL e-Golf, outright. How I treat and recharge my traction battery may vary significantly from how you use yours, and whether you lease and don't care at all about your battery condition, or whether you are in it for the long haul. The 2015 SE VW's leased or owned with the 3.6 Kw charger on board have battery packs that will never suffer the potential abuse any e-Golf with the DC quick charger feature might at the hands of multiple DCQC recharges in the interest of saving time over battery life. All the above is IMHO and YMMV.
 
Back
Top