REPLACING 12V BATTERY

Lots of folks replace their own 12 V batteries.
Sometimes finding an exact replacement is a bit difficult.

 

They probably had to reset the clock...

 

You might need to get it to "relearn" the window auto-up function. IIRC, you run the window down, then up, holding the switch up all the while till it's up, then an additional 2~3 seconds.

Yeah, Pep Boys sells a compatible Bosch battery, dimensionally identical, proper posts, vent port, spec's. It goes on sales sometimes for around $145. They'll install it for that price, but it might be preferable to do it yourself, DIY you tend to be more careful and thorough, clean the clamps for example.

 

You might have to reset your radio station, clock, as FuelMiser said.
If you a have a 12v battery that you can hook up to the jumping point under the hood, you shouldn't have to
do anything when you replace the battery. Just cover the positive terminal so it doesn't touch ground! OUCH!

 

finding an exact replacement is easy, there are 4 or 5 on the market now.

i think the dealer is wrong about the warranty, i would delve further into that. i know the new one is 2 year full replacement, then several years pro rated.

 

There's a gizmo for connecting jump packs to the OBD port, for providing volts during battery replacment. Here's one example:



Google "Clore Memory Saver Connector"

 

The hold-down bracket over the battery is an odd-design, intolerant of any variation in battery height. I found when I swapped in an Optima Yellow Top, even though spec'd height was the same, it was slightly higher, and I had to resort to a shim washer under the bracket at one side.

A more typical hold-down bracket has these long hook bolts with generous threading for nuts at the top, will accomodate plus/minus 1/4" in height variation.

Bottom line: if you're going to DIY a swap in a store parking lot, bring a few washers, appropriate for the bolt diameter.

 

The prius tend to trickle charge the aux battery, it’s always in need of a full charge, a good idea is to once a month, after checking the air pressure, hook up your 2 amp trickle charger overnight, top up the 12v to keep it healthy.
Because the battery is in the cabin and not in front with the motor, it’s a sealed battery, and must be replaced with a sealed battery, the oem battery is minimal, Optima makes a yellow top, sealed, deep cell (rechargeable) battery that fits in the prius, the optima also needs a monthly top up.

So keep your tires between 40-50 lbs, keep the cabin air filter clean and top off the battery monthly.

 

The OEM battery is no slouch, typically a Yuasa: I believe it has higher "amp hours" than the Optima. It can be pricey though.

 

My U1 AGM battery cost $65 new, is almost 3½ years old now, and is still functioning well.

 

My battery is over 5 years old. How can you test it to find out if it's still good? I'd rather replace it before it fails. It's given no indication that it's bad.

 

They usually don't give any indication before they fail.

With conventional cars where the 12 V actually cranks the engine, you might notice that it was cranking slowly.
Not so with a hybrid.

Most any place that sells car batteries can test it.......but when it's over 5 years old, it might test good today and fail tomorrow.
Time to get a new one while you can do it on your own terms.......instead of calling AAA from the side of the road.

 

Easiest way is to check the battery voltage after sitting overnight.

Once you have that, you can see what the voltage is and of above 12.5 volts, you should be good for awhile.

Getting a battery maintainer helps increase the longevity of the battery.

Just retired our 2010’s original 12 volt January 2nd of this year after 8.5 years in service.

If you have never drained it, keep an eye on the voltage and you should be fine.