Posted: Mar 31, 2017
What Size Battery Fits the Toyota Prius?
What size battery fits a Toyota Prius? That's a question we hear quite often, sometimes from folks who are surprised to learn there is more than one type of battery in the Prius. There is actually a 12-volt auxiliary battery located in the rear of the Prius and OPTIMA Batteries makes a direct-fit replacement for it. You can order it here and have it shipped for free directly to your house.
If you're not much of a do-it-yourself type of person, but you need to know the exact battery group size to purchase, it is an OPTIMA DS46B24R YELLOWTOP and it is considered a direct-fit replacement for nearly every Toyota Prius (you can verify your fitment by clicking here). Being a direct-fit replacement is important in the case of the Prius, because the battery is located inside the passenger compartment. Anytime a car battery is located in an enclosed area (including the trunk or interior), it should properly-vented to the outside atmosphere and the DS46B24R YELLOWTOP does have a vent port for connecting a hose that leads to the outside atmosphere. All Prius batteries came this way from the factory and it should be no trouble to connect the vent hose to the port when installing the battery.
There are also some batteries that may have similar physical dimensions to a DS46B24R YELLOWTOP, but the terminals are standard SAE terminals, while the DS46B24R terminals are much smaller (often referred to as "pencil posts," because their diameter is much closer to that of a pencil, while the diameter of standard battery terminals is closer to that of a nickel. If you get a battery that does not have these pencil posts, it will require additional time and probably additional expense, to adapt the Prius terminal connections to those larger diameter posts.
Dealerships can obviously get the job done correctly, but replacing a Prius battery is not an overly-complicated procedure, that couldn't be handled by a local mechanic. We called area mechanics and most quoted us a price of around $20, although many indicated they install batteries for free, if they are purchased at their location. While the process is slightly more involved than replacing a battery in a traditional car, that is located under the hood and near the engine, it can be done relatively-inexpensively. If your retailer sells you a DS46B24R YELLOWTOP, ask them about free installation (many battery retailers do offer this service, including national auto parts chains and Interstate Battery dealers, who can also order this battery).