dead starter battery after 3-week inactivity - all cars?

The battery of prius are inside the cabin, not outside near the engine like the rest of the cars....
So will last better than the Mazda for sure...

 

It is a problem common to all modern cars; it is just a matter of degree.

The hybrids have smaller 12 V batteries because they don't actually run a starter, so they will go flat due to "parasitic" drain sooner than a conventional car with a bigger battery.
It is easily solved with an inexpensive "smart" battery maintainer/charger during times of little or no use.

It could be a problem if you leave your car at someplace like an airport for weeks on end.
Then you would need a portable aux. battery.

P.S. This has been discussed in some great detail on here RIGHT NOW in an ongoing thread.
Have a look.

 

Since you are 'just looking' I will slip in here with my 'who should not buy a Prius' post, which includes those who do not drive for months at a time. (you can carry a jump pack or trickle charge if you leave it unused at home)

considering a Prius | PriusChat

 

Ask your friend how old is the 12V battery. If it's the original, it's no surprise that a 13 y/o battery loses its charge after sitting 2-3 weeks.

 

Since you are 'just looking' I will slip in here with my 'who should not buy a Prius' post, which includes those who do not drive for months at a time. (or trickle charge)

considering a Prius | PriusChat

 

i would get the mazda. 4-7 years is not great payback and the prius 12 volt is a known weak spot. un less you really really really want a hybrid, get the mazda.

 

+1 to asking your friend how old the 12V battery is; it's relatively normal to see them needing replacement after 4 years, though many last several years longer than that. Roughly a $200 item, I think.

The Prius should have no problems starting in cold weather; most cars have trouble starting in the winter because the 12V battery can't supply as much power when it's cold, so the starter can't turn the engine over as rapidly. In the Prius, the 12V battery is only used to boot the computers and close the relays for the HV battery; starting the engine takes power from the traction battery, which has plenty of power to start the car on the coldest day of the millennium.

As far as winter mileage, the Prius will lose a fair amount of mileage, but how much depends on many, many factors. If you take a lot of short trips (<5 miles or so), the car probably won't warm up, even in summer, so the engine will run more. In the winter, it will take even longer to warm up, although you can choose to block your grill to help the car retain heat, if you so desire. On the other hand, if you spend most of your time on the highway, you might not lose too much, since the engine is always on anyway, winter or summer. It also depends how much you use the heat - people who are nuts about saving on fuel (like me) will only use enough heat to keep the windshield from fogging (or frosting). Many others decide its worth a little extra gas to not have numb fingers and toes. If the car isn't fully warmed up (or if you are stopped for long enough that the engine cools off), it will run the engine to provide heat.

Overall, I'd suggest checking out both, and see which will make you happier while you get from point A to point B. Don't worry too much about the small price difference between them; if you want to make the best investment, put your $25,000 in a mutual fund and buy a bus pass instead.

 

12V Battery Replacement? Opinions Please | PriusChat may help the OP.

Yes, if a Prius is left for too long w/o anything to help charge the 12 volt (and driven (or rather in READY mode) for very little time), the 12 volt will go flat.

I got an Optimate 4 (that I mentioned at Which battery charger would you recommend? | PriusChat) that I use w/my Prius now that it mostly sits since my Leaf is now my primary car.

I posted a few other maintainers/slow chargers that I was considering at battery tender/maintainer suggestions | PriusChat. Slow/low amperage because Toyota warns that charging at too high an amperage will damage the 12 volt AGM battery.

 

Since I've gotten my Prius, I have to keep a maintainer on the Lexus because the security system will weaken the battery after setting for 2 weeks, so Prius is not the only car affected. How long will the Mazda set before the security system affects the battery?

 

zuzu's petals.