Fridge design on 12v battery?

If you use that included cigarette adapter in an unmodified Prius dash socket, the power will be cut whenever you shut down. Your battery will be fine.

We have a small fridge for the cars and it comes with a secondary defense system to keep the battery charged: if it detects the voltage is getting kind of low, it turns itself off in the hopes that it saves enough power in the battery for another startup. We don't have to worry about that in our Prius, but in our other car the cig socket is not switched- hot to the battery at all times.

 

IF the power is connected to a socket that stays powered when the vehicle is OFF.......then yes, in just an hour or two most likely.

 

I hardwired my fridge in my prius, the fridge in my prius has a low voltage setting, actually three. the fridge will turn itself off if the battery voltage goes below the selected setting.

 

If this is the kind of fridge that uses 60 watts more or less constantly, then knowing your Prius comes with a 540 watt-hour aux battery, you can do the math and see how long a fully-charged, new-condition aux battery would hold up that fridge (if there were no other loads, and you didn't mind it being fully discharged at the end).

Then take that and cut it in half or smaller, to account for (a) probably not having a brand-new aux battery, (b) the aux battery in a Prius usually not being fully charged to start with, (c) a few other loads that stay active when the Prius is off, and (d) not wanting it to fully discharge.

Of the different kinds of fridge you can get, usually the thermoelectric kind are less money, but those are the ones that typically will draw 60 watts or so more or less the whole time you're using them.

The kind based on compressing refrigerant are more money, but use a lot less juice, so the battery can hold them up longer. (They'll draw more than 60 watts when cycled on, but they're cycled off a lot of the time.)

 

540 watt-hour?? Do they really have that much capacity?

 

You might be confusing a watt-hour with a cold cranking ampere.

 

I’m not. Off the top of my head (it’s too blanking cold to step in to the garage to check it) but I think my battery’s CCA is around 295 and the other rating is 45 (amp hours or is it reserve capacity?). Neither one of these converters to that watt-hour capacity do they?

 

45 amp-hours X 12 volts = 540 watt-hours.

 

Thanks! (Sure beat getting cold to find out)

 

Amp hours x 12(volts) gives Watt hours. 45 x 12 = 540

 

And thanks to you also (saved me the pain of the cold)