Vic
Posts: 3
Joined: Mon Nov 19, 2018 12:37 am

15 amps or 20 amps

Mon Nov 19, 2018 12:45 am

Brand new EV owner. I just bought a 2015 B250. All I have is the slow charger that came with it. I may not need more than that, given it will be a true commuter car. I have a 15 amp 110 charger plug very close to my car there's another 110 outlet that's 20 amp, it's not as convenient. Would the 20 amp charge the car substantially faster? I also noticed on eBay for about $200 I can buy a cord that fits my clothes dryer its 220 and not far from where I park. How much faster will that 220 charge than the 15 amps or 20 amps 110? Thanks for your help for the Newbie.

JeffRay
Posts: 805
Joined: Thu Dec 11, 2014 9:12 am

Re: 15 amps or 20 amps

Mon Nov 19, 2018 5:25 pm

Vic,

Welcome. In general, as my last physics course was back in the day, a 220v charges up to 5x faster. If you are saying you will be charging overnight, you are right that a solid 10 hour charge will restore around 40% of the battery. If you are in warm climate area, 40% will get you over 40 mile roundtrip. So you can top up every night with your existing convenient outlet. I can't comment on 15 v 20 amp but you can search this forum for topics on charging.

It is generally not advised to use a long cord to charge using 220v given a concern about overheating the cord or outlet. I figure one hour gets me 25% of my charge back, so only four hours to get 100% back.

Hope this helps directionally if not specifically.

Enjoy the ride Vic.
Jeff in NYC
MB '17 B250e; MB '06 E500W; MB '81 380SL

GlennD
Posts: 449
Joined: Mon Jul 21, 2014 5:26 pm

Re: 15 amps or 20 amps

Mon Nov 19, 2018 10:45 pm

At work I charged for free. In my case a 208VAC EVSE worked for me. Now as a retired person I charge at 240VAC at 40A. As much as I drive I could get away with 120VAC trickle charging, I charge at 75% of the 80% default. The EVSE was upgraded to 40A but just because,my 30A EVSE was fine. The Quick Charge Power cable replaced the cable on a EVSE I sold so the charge was minimal. I really have the time to trickle charge

I really like the size of the Quick Charge cable. I purchased a 40A cable from TucsonEV and the cable was huge. Both worked for a fixed installation.
2014 Cirrus White B Class (Totaled).
2016 Urano Gray eGolf.
I loved the VW but it was too hard to get into for my aged body.
I am back to another 2017 Cirrus White B250e.
Blind Spot Assist, Performance 3 and Sahara Beige interier.

Vic
Posts: 3
Joined: Mon Nov 19, 2018 12:37 am

Re: 15 amps or 20 amps

Tue Nov 20, 2018 8:07 pm

Good info, thank you. Vic

hallcp
Posts: 13
Joined: Mon Jan 07, 2019 12:45 pm

Re: 15 amps or 20 amps

Thu Jan 17, 2019 9:16 am

I was curious about this too. On the Clipper Creek website they have a chart of the charge times for various cars, based on which charger you use.

My interpretation of the chart is below:

Max charge rate: 9.6 kw
Battery capacity: 28 kwh

Time to charge:
120V 15amp: 20 hours
240V 20 amp: 7.5 hours
240V 25 amp: 6 hours
240V 30 amp: 5 hours
240V 40 amp: 3.5
240V 50 amp and up: 3 hours

The original chart is here: https://www.clippercreek.com/charging-times-chart/

By comparison, my Chevy Volt charges as fast as it's ever gonna charge with a 20amp 240V circuit.

GlennD
Posts: 449
Joined: Mon Jul 21, 2014 5:26 pm

Re: 15 amps or 20 amps

Thu Jan 17, 2019 1:23 pm

Do not forget the Lear (Mercedes) charger defaults to 8A. For 12A would have to select it each time . 8A on a B would take forever.

Beware of Chinese EVSE's on eBay. Many claim to be J1772 compliant even though they are not. There is very little to no regulation in China. It is the technical Wild West.

Do not forget that any circuit must de-rated to 80% for EVSE use. For example my 40A EVSE requires a 50A circuiit.
2014 Cirrus White B Class (Totaled).
2016 Urano Gray eGolf.
I loved the VW but it was too hard to get into for my aged body.
I am back to another 2017 Cirrus White B250e.
Blind Spot Assist, Performance 3 and Sahara Beige interier.

GlennD
Posts: 449
Joined: Mon Jul 21, 2014 5:26 pm

Re: 15 amps or 20 amps

Thu Jan 17, 2019 1:35 pm

hallcp wrote:
Thu Jan 17, 2019 9:16 am
I was curious about this too. On the Clipper Creek website they have a chart of the charge times for various cars, based on which charger you use.

My interpretation of the chart is below:

Max charge rate: 9.6 kw
Battery capacity: 28 kwh

Time to charge:
120V 15amp: 20 hours
240V 20 amp: 7.5 hours
240V 25 amp: 6 hours
240V 30 amp: 5 hours
240V 40 amp: 3.5
240V 50 amp and up: 3 hours

The original chart is here: https://www.clippercreek.com/charging-times-chart/

By comparison, my Chevy Volt charges as fast as it's ever gonna charge with a 20amp 240V circuit.
The car charger sets the current. No B charges at 50A.

A Volt charges at 14A at 240VAC.. I was under the impression that it charged at 16A but I was wrong.

Every car's charger sets the current. Buying a larger than necessary EVSE is a waste of money.
2014 Cirrus White B Class (Totaled).
2016 Urano Gray eGolf.
I loved the VW but it was too hard to get into for my aged body.
I am back to another 2017 Cirrus White B250e.
Blind Spot Assist, Performance 3 and Sahara Beige interier.

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