HPWC 80 amp vs. 40 amp

[bonnie]

I'm with stevezzzz - I've charged my Roadster at home off 40amp service for over three years, many times with a near empty battery - and never wished for an HPC and 70 amps on the wall.

That said, I AM in the process of installing an HPC. Not because I need it. But because of all these parasite friends of mine who have electric cars and 'do you mind if I plug in while I'm here?' (I know they're really just coming over to steal my electrons & not see me ... ).

Seriously, you'll find after you get an EV that you'll likely get more involved in the local community. And then you make friends. And some of those friends come from greater distances and do need a charge, maybe more than 40 amp (unless you really like them and they're planning on staying overnight).

I'd put in the higher service. It gives you more options.

 

[scaesare]

In three years there has been one time I need to charge at a higher rate. And even then it was a want to not a have to. Normally I charge at 40 amps as I believe it is easier on the grid and the battery pack.

A "1C" charge power for the large pack would be 85kW. A 240V/40A charge current only represents a 0.113C rate. Increasing it to 80A only makes it a 0.226C rate... less than a quarter of the nominal rate of 1C. And rates of 2C or more when with conditioning (thermal mgm't, current shaping, etc...) are commonly employed with no long-term harm to the battery expected.

The difference in charging your pack at 40A/80A is going to be indiscernible as far as pack health goes. While there may be other reasons for it I wouldn't include pack deterioration as one of them.

 

[roblab]

- I don't consider the UMC "permanent installation" device. As a matter of fact the "M" in "UMC" stands for "mobile". I understand leaving it plugged in most of the the time, but I'm not sure that time, flex, weight, etc... won't take it's toll on the plug-head/adapter combo.

My experience in 36,000 miles of driving: Unplug the UMC when you know you will be charging away from home and toss it into the car. IF YOU EVER have any difficulties with the UMC, so far, Tesla has simply replaced mine on the spot, no charge. If it "wears" from being plugged and unplugged (which it is obviously designed to do) and they deem the wear to be a possible impact on safety, it gets replaced.

 

[scaesare]

My experience in 36,000 miles of driving: Unplug the UMC when you know you will be charging away from home and toss it into the car. IF YOU EVER have any difficulties with the UMC, so far, Tesla has simply replaced mine on the spot, no charge. If it "wears" from being plugged and unplugged (which it is obviously designed to do) and they deem the wear to be a possible impact on safety, it gets replaced.

You missed the point where I said I want a charging cable in the car with me at all times.

And "IF YOU EVER" and "so far" might be a bit at odds.

 

[brianman]

I AM in the process of installing an HPC. Not because I need it. But because of all these parasite friends of mine who have electric cars and 'do you mind if I plug in while I'm here?' (I know they're really just coming over to steal my electrons & not see me ... ).

How many are you installing for the picnic in July?

 

[sranger]

I did not order it as I know it would not do me any good. The only 40+ amp charger any where near me is the Tesla Service center and it is only 13 miles away. I have to keep a milage log and i almost never exceed 150 miles in a day of driving.

For long distance driving the SC network will be better and the only other higher capacity chargers in the four adjoining states are mostly Chademo chargers...

I just do not think I would ever be able to use the extra capacity so I got the Sound upgrade instead as I will use it every day...

 

[jerry33]

How about option 3: NEMA 14-50, for less than $500 (~$200, maybe less if installed yourself?)

I can't think of a reason to get the HPWC and put it on a 40A circuit. You get the same charging rate as the 14-50, for many times the price!

The cleaner install and extra cable length come to mind. I found out that the UMC cable won't really work if the plug is at the front of the car. It reaches but everything is stressed. I only have the UMC, but an HPWC is on the list (admittedly not in the top three right now.)

 

[techMology]

I know you're all waiting with bated breath to know what I ultimately decided, so I thought I'd post which direction I'm going.

...and the winner is: 80 amp HPWC on separate service!

Cheers:
- Quicker charging *if* I need it for a quick turnaround: this one gave me the most to think about. There's something in the home theatre community called WAF (wife acceptance factor), and it factored in here. All it would take is one "honey, you can't use the car to drive to Niagara Falls on a whim because it isn't fully charged" for me to regret not getting the 80 amp service.
- I live in Canada: so, nasty (especially this one) winters, which means I'll be using more energy than most of y'all (nod to the south) 6 months of the year. This brings me back to the first point; if we need to turnaround quickly, 80 amps will add range twice as fast.
- I'll be fully utilizing my twin chargers: I opted for them primarily for road tripping (thank you, Sun Country Highway), but not being able to utilize it at home stuck in my craw (second nod to the south!).
- The HPWC as many pointed out is just nicer to plug into every day. I want my UMC to live in the car.
- Another EV: we are a one car household now, but things change, and I'd like any additional car we potentially get to be an EV.
- PlugShare: I like the idea of sharing 80 amps with other MS owners in case someone needs a quick top-up. There are no SuperChargers planned for anywhere around here.

Jeers:
- Installation cost: it'll be about another $1100 or so.
- Monthly cost: this was the biggest one, but only out of principal. The $20 recurring fee due to the new service being required. Thankfully, my utility is offsetting that cost with an incentive.
- Installation style: I'll be running an aerial cable to my garage (it's detached and about 40 feet from my house) versus along the back of the fence (and buried). Aesthetically, it won't be as nice (more WAF here). Yes, I could bury it, but it would cost about an additional $3500 (and it's winter, so, possibly more - that was a quote I received in the summer).

So, if you're in the Beach (yes, really) in Toronto, look for a HPWC on PlugShare coming mid-March. That'll be me!

 

[pilotSteve]

Thanks for informing us techMology. Similar reasons I want with 100A/HPWC almost a year ago. No regrets, and agree with all of our "Cheers" (well, I live in Vancouver WA not Canada).

 

[steve841]

Ok, i will chime in...

Would it be so bad to try a month or two with the 14-50?

You can always grab the HPWC later (and possibly cheaper used) if really needed.

 

[techMology]

Ok, i will chime in...

Would it be so bad to try a month or two with the 14-50?

You can always grab the HPWC later (and possibly cheaper used) if really needed.

There is a $1000 rebate in Ontario for installing a high powered EV charging station. The HPWC qualifies, a 14-50 does not.

So, I'm only paying $300 CDN + tax for the HPWC. Plus, I would have to have an inspector come check the work (again) to ensure it's done right in order to qualify for the rebate.

Would it have been so bad to go 14-50 first? No, it wouldn't. But, it wouldn't have saved me much money.

The two installations I was considering were completely different. I wouldn't have been able to upgrade to 80 amps with the other option without spending a lot more (new panel, new service from street).

 

[Blaze]

I debated going with the 100 amp HPWC, and decided I just wanted it. S is to be picked up March 15, 2014. The unit arrived FedEx today. My electrician is talking with the power company. I understand we will need to move some gas piped to have the required clearance for the second meter. This will be a process with permit inspection,making holes to get the wire from the panel to the garage. Not sure where challenges await....

 

[scaesare]

I know you're all waiting with bated breath to know what I ultimately decided, so I thought I'd post which direction I'm going.

...and the winner is: 80 amp HPWC on separate service!

Cool... sounds like many of your reasons were similar to the ones I posted as mine...

Enjoy!