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Prius Resale Value and Other Issues

Does this project affect resale value for all Prius owners?

An interesting issue came up in the Priusonline forum.  Avid poster BIF added this thought to the discussion of using Prius power:

If the rest of the world begins to think that people can power their houses with their Prius ICE's, you can watch our resale values crater to rock-bottom levels.

Why? Because we only have an odometer, which only tells us how many revolutions the wheels have made. There's no mechanism to tell us how long the gas engine has been running. Think about it, why would ANY buyer want to "pay up" for a used car if he can't tell how heavy its service was?

Time to rethink our way of measuring the life-expectancy of our cars! Until then, I don't want to hear any more of this "use my Prius as a house generator" crazytalk.

Stripped of its dire conclusion, it is a valid question.  (And what is the internet but a bunch of crazytalk anyway?)  How does one respond to this?

First, a major purpose of this project is that it's suitable primarily for emergencies.  One expects to drive a car an hour or so per day.  One expects to have power outages a few hours per year.  In this case the extra usage is negligible and shouldn't affect anything.

Next, resale value depends on a number of imponderables, some far more significant than a few extra ICE hours.  Perhaps the vehicle has been used as a taxi, perhaps in stop-and-go traffic,  perhaps for road racing or towing a boat.  The odometer reading is a poor proxy for true usage, but it, along with the honesty of the seller or used car dealer, and perhaps an expert inspection, is pretty much all we've got, and really all we've ever had.  Perhaps a small number of Prius owners will use it to power their hunting cabin for days on end after driving only 50 miles to get there, but it seems unlikely that this will cause the resale value of all Priuses to plummet.

Finally, one would hope that the unadvertised and valuable ability to use the Prius for emergency power would cause the resale value to increase!  I, for one, bought it with that in mind, and others, especially in hurricane-prone areas, will do the same.  As long as this remains the idiosyncratic project of an eccentric New Jerseyite, nobody will care and it will have no effect at all.  If it becomes mainstream after a lot of crazytalk and promotion, it will be a boon to sellers.  

Still, I wonder if there is any way to determine how long the ICE has been used.  It wouldn't surprise me to find statistics like that are kept in the Prius computer.  If you know, pass on the info!

How good is your Prius battery?

In considering the above question, I realized that one can get a good reading on how much use the Prius generator/battery has had, at least to the extent of how it may be reflected in the efficiency of the battery.  When you charge a battery, e.g., when braking, some energy is wasted as heat and some is reflected in the increased charge of the battery.  Likewise, when you discharge a battery, e.g., when accelerating, some energy goes to the motor and some is wasted as heat.  (This is an argument for not braking even in the Prius!)

As batteries get older and weaker, their charge/discharge efficiency decreases.  Because the battery is maintained insofar as possible at a constant state of charge by the Prius computer, one would think that the ratio of input energy to output energy measured over a reasonable interval would give a good indication of the quality of the battery.  This should be possible to measure since the current sensor and battery voltage are accessible.

Add a "to be continued" to this thought...

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