Toyota Prius Prime Battery Discharge Rate When Sleeping In Car With AC Running

How Long Will the Prius Prime Battery Last When Parked Using AC?

I’ve started to collect data using my 2017 Prius Prime to figure this out. I’ve seen people asking this question in the context that they want to sleep in their car at night (car nomads and car campers), so I’m grabbing night time data as well as daytime data.

Test Conditions

Each test I do, I have the AC on Eco Mode, set at 70F, both the dashboard vents and floor vents open, and 3 bars on the fan speed. I’m assuming summer time conditions, and as such, I’ve designated a full battery as one that is showing 27 miles of charge left on the car’s display.

Results

So far the summertime solar gain (i.e. the car is sitting in the sun, heating up) significantly impacts how fast the battery is drawn down to a depth of discharge consistent with zero EV miles available for driving. It is best to use the AC at night and in more hospitable temperature conditions, which is good news for car sleepers. I’ll continue to collect data; I’m curious about high temperature nights in the San Fernando Valley, so hopefully some hot nights start happening soon.

Solar Gain Condition	Outside Temperature	Miles Draw Down	Time Draw Down	Implied Time From Full Charge (27 miles) to Zero EV Miles (Hybrid Mode Starts)
Daytime	91F	26.1 to 21.8 = 4.3	30 minutes	3.14 hours
Daytime	75F	26.2 to 25.5 = 0.7	6 minutes	3.86 hours
Daytime in Full Shade	88F	27.2 to 26.1 = 1.1	22 minutes	9.00 hours
Daytime in Full Shade	91F	26.2 – 23.9 = 2.3	47 minutes	9.20 hours
Nite Time	83F	14.3 – 13.6 = 0.7	10 minutes	6.43 hours
Night Time	69F	20.8 to 20.0 miles = 0.8	20 minutes	11.25 hours
Night Time	69F	19.3 to 18.5 miles = 0.8	20 minutes	11.25 hours

How long it takes to use full battery charge on a Prius Prime when parked, running air conditioner at 70F

How Long Will the Prius Prime Battery Last When Parked Using AC?

Test Conditions

Results

Further Reading