OK. It’s really not HAL 9000, although you’ve got to admit, it looks a bit like one of HAL’s ubiquitous camera eyes.
Actually, it’s a charger used to re-charge the two 12V batteries that power the mobility chair in the background. In my Kill A Watt™ EZ measuring madness, I decided to see how much power the charger uses. It’s a good example of an appliance that can generate a significant phantom/vampire load, if left on all the time.
What I found was that, to bring the batteries up to a full charge after being very close to completely run down, required the charger to run for about 9 hours. The Kill A Watt™ EZ recorded a total power consumption of 0.91 kWh, at a total cost of $0.18.
Then, I reset the Kill A Watt™ EZ and left the charger to run overnight, even though it was idle now and no longer charging the batteries. After 11 hours, the Kill A Watt™ EZ reported that the idle charger still consumed .11 kWh of power, at a cost of $0.02. It might not seem like much, but the cost estimation function of the Kill A Watt™ EZ shows that this comes to about $1.46 a month, and $17.78 a year. That’s more than it costs to run my cable modem continuously for a year. But unlike the modem, all that estimated idle time is serving no purpose whatsoever.
Of course, in reality, the charger wouldn’t be idle all the time; a certain percentage of its time would be spent trickle charging the chair. But still, the morale of this story is that there’s no sense in leaving the charger on continuously, as long as the chair’s batteries have a sufficent amount of charge on them.
“I’m sorry, Dave. I’m afraid opening the pod bay doors would waste too much energy…”