Tim Stevens for Engadget:
While we haven’t been able to confirm all the “several” supposed cases of this happening, we did hear back from Tesla issuing a statement (after the break) that more or less affirms this could happen. Tesla uses a number of so-called “countermeasures” to prevent this, up to and including calling the owner should a battery pack trail dangerously low.
To recap, a Web site called theunderstatement reports that Tesla’s all-electric roadsters can incur very expensive, out of warranty repairs if their battery cells are completely discharged – expensive to the tune of $40,000 to replace. Tesla says its vehicles have countermeasures to protect against this from happening.
I think the old adage “out of sight, out of mind” comes into play. Tesla roadsters are, by and large, the playthings of very wealthy people who don’t use them every day – and at least in some cases, don’t use them for weeks or months at a time. Enough time that the batteries can completely discharge and then run them very expensive bills.
My takeaway: If you’re going to fork out $109,000 or more for one of these things, the least you can do is take care of it according to the manufacturer’s instructions. Running a $40,000 bill just because you’re being careless with it tells me that you’re pretty stupid with your money and your toys, and you probably don’t deserve either.
Can’t they just instruct their valet or footman to plug the thing in for a couple hours a week? Of course if the worthless layabout forgets, he’ll be in for a sound thrashing!
Exactly. Gotta make sure your pets have food too or they will need replacing also.
Except that EV’s are being heralded as the future of motoring, and this shows just how impossible these cars are (at this point) for daily use. Remember this technology is supposed to be used for cars in the 40-50k range very soon.
There should probably be a lead-based (deep-cycle) battery to provide parasitic loads, getting that from the main Li-ion is indication that either their sleep mode needs *serious* work or they’re just lazy.
If they are depleting four percent of a 40 kWh battery pack a week, they have parasitic loads many tens of times higher than a regular car (typically, 50 Ah car battery times 12V is .6 kWh). When was the last time you depleted a car battery by not running it for a few weeks?
The only legitimate thing it could be is if the battery monitoring took all that — but I suspect that it doesn’t. Self discharge on notebook battery packs, which include charge monitoring as well, is minimal.
I suspect that their fancy software (a tow mode accessible via electronics? Really?) means they are keeping a touchscreen active permanently. That’d do it.