Tesla Mode S: 20,000 EV miles loss due to vampire drain

If that's accurate that means people who leave their cars parked 100 days at a time w/o out access to a plug should not buy Teslas. I've been driving for over 30 years now and can easily recall how many times I've done that, zero.

 

I'm not sure what the actual phantom losses will turn out to be for the car, but I'll not be surprised to hear in excess of 50 watts. Homes in the US are often hundreds of watts. A year or so ago I went on a rampage in my home in NM and turned off every single vampire that I could find in the house*, and I STILL had a 20 watt phantom load.

One fellow reported (on Teslamotors forum LOL) that his home consumes 20 kWh a day when he and his family are away !

My point is that the Tesla car is far from unusual in having a high phantom load. An extraordinary amount of electricity is wasted in the US.

*Really. I went so far as to disconnect the doorbell, the remote controlled fan, the home furnace in the summer, and the garage doors. I even put the microwave on a switch. The only device I found and left alone was the oven, and that was because it was on 220V.

 

[RANT] A real on/off switch on any device, including a car, should be available and able to really turn it completely off. I design electronics for a living and it is a pet peeve of mine that way too many things (needlessly) cannot be turned off. I have no problem whatsoever with any device having standby selection or sleep selections as the preferred control. I have no issue with truly turning something off requiring a long wait or lots of steps for it to come back on. I do have a problem with requiring a dealer or service expert turn it back on.

My problem is some folks want the real On/Off quite often and quite a few want it sometime during the life of the device...and all want this for any number of good reasons. Sooner or later this will become a deciding factor in buying electronics, including EVs.[/RANT]

 

What? No.
The 1% from Tesla isn't a hard number, but a rule of thumb. It likely is for a car without power save on.
One of the Model S owners stated they lost 9 miles over 3 days. After that it was a mile a day.

I agree, but Tesla might have to balance off and leaving the car able to communicate in the event it is left for a real long time unplug, to save itself from the battery bricking.

 

The rant was not an On/Off switch that can cause more harm than good in some situations. I would hardly want an operational pacemaker to have an On/Off switch for example. Likewise there are a lot of things I have had to design to make it extremely hard to be turned off, such as flight control systems. To turn those off is (and should be) a very deliberate sequence of interlocking steps. But these are very few and far between. In the Telsa case, without knowing the real technical details, I really cannot say if the design is too power hungry or if what they have is necessitated by legal, regulatory, or warranty factors. But I am very use to manufacturers making devices extraordinarily wasteful of power in order to save a few cents on capital costs.

 

Seems rational conduct since in the US at least, most consumers are not interested in avoiding phantom losses. Energy is cheap, and they don't know how to figure out the cost regardless.

 

Amazing how much you learned from people making the nickel mine and "Hummer is cleaner than a Prius" arguments.
Try your math again.

 

Ok, now that that is fixed...
Why take the worst case without mentioning best case?
it could also mean 0.33% drain per day in seasonable weather.

How much energy/efficiency is lost due to under inflated tires? Due to poor engine maintenance? Etc.
All cars have efficiency losses. The amount of vampire drain can easily be replaced with a simple 110 outlet which is available just about anywhere.
So on a convenience factor, it is a non issue.

On an energy efficiency basis, it is still far more efficient than any gas car, even the upcoming Elio.

On a CO2 level, all depends where you get your energy from and once again, their are bigger losses elsewhere.

 

BMW's bi-fuel gasoline/hydrogen ICE's, that I think was actually available to the public, liquid hydrogen tanks would go dry in about a week of sitting parked.

This is a proposed hydrogen permeation rate maximum for a FCV from this 2012 study, Allowable hydrogen permeation rate from road vehicles , for EU regulations.
Table 3.

Proposed allowable permeation rate.

New or Simulated end of life container Minimum testing temperature (°C) Maximum allowable permeation rate
New 15 6.0 mL/hr/L water capacity a
20 8.0 mL/hr/L water capacity a
Simulated end of life 55+ 90 mL/min/std passenger vehicle

With its 122.4L tank, the Mirai could lose up to 734.4mL, 979.2mL, or 11.016L of hydrogen per hour, depends on what the final conditions of the certification test. If these are the final maximum rates the EU settles on to avoid garage explosions from hydrogen permeation of FCVs, then that means a daily loss of 14% to 19% is acceptable.
I'm positive that the actual rate of FCVs offered for lease will be much lower than that. I think 1% would be high, but it will still be happening. Even the Prius doesn't have zero evaporative emissions.

And it could be as low as 0.35% or 0.3kWh a day.

In the Tesla thread I linked too, the OP there saw a 10 mile/day loss over 3 days. It was a new car off getting a protective film or window tint applied. The owner didn't yet know about the power save setting, and likely that he could turn off the cell connectivity to further save power. Then the technicians doing the work may have turned on the radio or just checked out the display.

The responses to that thread were all much lower than that, and also lower than the OP article here. Though I don't remember any being at as low as a temperature, but some were winter temps.

The 1% in the Tesla owner's manual is just a rule of thumb. It is the owner's manual, not the technician's one or engineering paper. It is included to let the owner know that they can't just leave the car unplugged indefinitely, and that they have to take the power loss into account when they do have to to leave it unplugged. Being an owner's manual, the 1% value may not have updated since the first version, and could reflect the VD from the beginning when it was really bad, or be 1% of the 60kWH pack.

The reality is the majority owners aren't going to leave their S unplugged for a hundred days. A week is likely the longest such time. Otherwise the car will be plugged in while parked at home, and just be another VD on the house. Which most that bought the car would be fine with as a minor cost to not use gasoline.

I know, and I would hit the switch on the power strip to the TV and cable box, but the wife is the last to use it before bed.
I was alluding to a couple of fools that bought Roadsters as investment, and parked them away in a garage without reading the manual. The batteries bricked, and they bitched, and then the press picked it up. Wanting to avoid a repeat of that, I can see Tesla being cautious, and choosing VD to let a car warn them if it might happen again.

 

My Ranger was a third car for awhile, so it sat most of the time. The pin grease for the front brakes dried out. This lead to the pads dragging on the rotor. Not only did it mean more gas burned, but also heated up the rotors and warped them.

A friend couldn't drive for a year. During that time, they did turn on the car, and even rolled it back and forth on the driveway about once on week. When I first saw him after he started driving again, there was a perfect little dome about the size of a quarter and a half inch high was sticking up from the hood. The strut had seized, broken through the the top mount, and hammered that dome into the hood.

Another friend bought a 1975 Chrysler Newport convertible that sat for ten years. It started right up on the gas in the tank. That old gas left gum and varnish on the valves that lead to bending push rods.

Motor bike riders hook the battery up to maintainers during the off season. The same should be done of any lead acid battery that isn't being used. Boats get winterized in areas with a winter before being stored away. The NiMH in a hybrid will self discharge will self discharge over time.

There is going to be a cost of letting any vehicle just sit for extended periods of time. Properly preparing them for long term storage has a cost. The Model S has vampire drain that has been reduced, but could be improved upon. It doesn't have worry about gasoline oxidizing and going 'stale', or diesel growing bacterial mats. Neither is motor oil oxidization and water condensing into it a concern. The low steel content means less rust to worry about.

Now, depending on the battery's SOC, leaving an S unplugged could have a more pressing time factor. It will likely cry for help before there is a danger of premament damage to the traction pack occurs.