Not having had a Spark, does it do anything when not in use--other than charge? With Tesla you're getting something that is at listens for a connection all the time. maintains the 12V battery, maintains the traction battery temperature, checks for things such as preconditioning and cabin overheating if you have those turned on, etc. That all comes at an energy cost.
For the Tesla:
First: to reiterate, the 5W (which is acceptable, borderline) is enough to:
1) allow instant door opening.
2) listen for wake ups (though they can be slow)
3) draw down the 12V battery
Cabin overheat protection: having this on does not impact vampire drain if it does not engage. I’ve checked.
Preconditioning: this is not vampire drain.
Battery temp protection: the car does nothing with the HV battery to maintain the pack temperature over a wide range of “normal” temps. What it does outside of those temps is not vampire drain. In any case this is not the reason for vampire drain (not does Tesla claim it is).
Again, the majority of the issue is what happens in the few hours it spends in a non-sleep state.
Spark EV:
Allows remote connections.
Allows preconditioning/lock/unlock/etc.
Keeps track of vehicle system status.
Does battery thermal management if needed. (Never seen any energy used for this in my Spark under any scenario, but it does happen at extremes.)
