Your Toyota Prius may be built to last, but nothing’s built to last forever, and the battery is probably going to be one of the first things to go. So now you’ve got to do a little battery shopping, and you’re going to have a few questions.
What’s the best battery for a Toyota Prius?
The OEM battery, or Original Equipment Manufacturer battery, is your best bet. You can get these directly from your Toyota dealer. If you’re shopping around, you’re going to be looking for a Toyota TrueStart AGM. No matter the make and model, the OEM battery is always going to work best.
Why is it that the OEM battery works so well? You can swap out batteries in your TV remote or flashlight with no issues, so why does a car require the original equipment? It’s all about specs. Here’s what you need to know.
Battery Group Sizes Explained
A Toyota Prius 12V Starter Battery is classified under group size S46B24R.
Now what on earth does that mean? If you’ve never read up on battery group sizes, this might as well be a foreign language. It tells you absolutely nothing about the size of the battery.
Here are the numbers you need to know:
- S – Terminal type. In this case, it’s an S.
- 46 – The BCI physical dimensions of the battery. 46 would be 10 3/4 x 6 13/16 x 9 inches in length, width and height.
- 24 – Voltage. 24 volts.
- R – Post configuration. In this case, the R means that the posts are reversed, so the negative terminal will be on the left, positive on the right.
It can be a real headache trying to make sense of every digit in a battery group size code, but good news: All you have to do is write it down somewhere before you head out to buy a replacement.
Lead-Acid, Lithium-Ion or SLI?
The Toyota Prius battery actually uses an alternative to lead-acid, AGM, or Absorbed Glass Mat. This results in a more durable battery, and one that doesn’t spill like a conventional lead-acid battery might.
AGM uses fiberglass that can be saturated with electrolyte, storing it in a suspended dry state instead of as a liquid. The charge in an AGM battery is up to five times quicker than a flooded battery, and it stands up better to low temperatures.
OEM vs. Aftermarket
If you can buy OEM, buy OEM. Here are a few reasons why:
- Aftermarket batteries aren’t typically built to the same standards as OEM. Automaker recalls are a lot more expensive than battery recalls.
- Aftermarket batteries might void your warranty.
- OEM batteries come with the same guarantees and protections you get with the battery that was in your car when you bought it.
- The OEM battery’s specs match up perfectly with the Toyota Prius — amp/hr, internal resistance, etc. An aftermarket battery might work, but the OEM fits like a glove.
And of course, it’s just fewer headaches to go with a battery that you know was built specifically for your car.
If You Must Buy Aftermarket…
You really don’t want to buy aftermarket. But if you absolutely must, like if you’re stranded and can’t find a Toyota dealer, our advice would be to make this a temporary fix.
First, make sure to buy the right type of battery. Check the group size number on the battery or in your owner’s manual. Take that into the shop, and find what you’re looking for.
Check the expiration date. The newer the battery, the better the performance you’re going to get out of it.
And as soon as you can, replace that temp battery with an OEM. You can keep the temp for emergencies, sell it, or give it away.
If you want your warranty to be valid, and if you want the best possible performance out of your car, you want to treat that aftermarket like a spare tire and swap it out for the real thing as soon as possible.
