2017 Prius prime battery low

Have you ever checked the fluid level in the 12V cells?

I had gotten used to the sealed AGM battery in our Gen 2 Prius and was not keeping an eye on the on the fluid level under the caps of the regular lead acid battery in our Gen 4 Prius. When I finally checked them 3 years after buying the car, I found them all to be low, so I added distilled water, but I'm afraid some damage may have already occurred. My not-quite-4-year-old battery is now showing signs that it is getting weak, although I have otherwise been very careful about never letting it discharge. (I keep a solar charger on it when the car is not in use). I wonder how many other Gen 4 or Prime owners have also neglected keeping an eye on fluid levels after having gotten used to the sealed batteries in the earlier generation Prii.

 

With COVID-19 restrictions, many people are not driving enough to charge the 12v battery. If you are currently driving less than 1 hour total/week, you may want to invest in the 12v battery charger/tender to maintain the 12v battery. Your price being quoted is not super high but if you DIY, it can be replaced around ~$100 with a compatible aftermarket 12v battery. That being said, if your current battery is still working, you may not need to replace it for a while. The Prius only need above 12v charge to start the computer, and it doe not require the clod cranking amp to start the engine.

 

primes suck the life out of the 12v battery because they draw a lot of power when the car is parked.

before doing anything else, get a second opinion. you can get a free load test at most auto parts stores.
in the end, 195 bucks installed is a great price.

 

I bought my car used from a VW dealer. They had let it sit long enough that the 12V went dead. They had a sister dealer (Toyota) recharge it and "certify" that it was good, then put it back on the lot for another month or two. There was no record of this service on the Toyota customer web site. The battery died within 9 months after sitting unused for a week.

I replaced it with a battery from Autozone for 1/2 the price that the dealer wanted to charge.

 

My 2 Prius C 2012 (230 000km and 170 000 km) still on their original 12 volts batteries... And I live in North...