Triple A aux batteries

It is better to use a $25 battery maintainer on the car rather than attempting to drive it a hour each week if there is no other reason. The car is always draining the battery when off, its called parasitic draw. It should be 15ma-30ma, easily measured by a mechanic or handy diy'er. If higher, say 90ma-900ma or more, the cause should be found and resolved, a more advanced task.

The brake actuator is failing. Get it fixed. Not cheap.

Battery Maintainer

Parasitic Draw

 

And stop connecting your charge leads right to the battery use the front jump point that's what its for.

Check the DC voltage on the front jump point. A happy Prius battery lives around 12.6 volts. Easy way to check how bad your battery is with the car OFF turn on the headlights on high beam. What does the battery voltage measure at the front jump point with that load on it?

 

agreed

 

Nobody knows the first answer because it varies WIDELY depending on the age of the battery and on what kind of power draw you have from accesssories.......and on how long it sits BETWEEN trips.......and on how HOT the environment is.
My wild guess: 50 miles a week.

And yes, it might explain the action of the brake "actuator".......or it might not.
You will see when you get a good, fully charged battery in it.

 

To prevent a bad crash on the freeway ?? I don't follow that logic.......or lack of.

And your wild guess on the cost might be WAY off.
It could be a loose fitting.
And a new pump might be a lot less than that.

Best to KNOW and not to guess.