12v Battery Replacement

The other day I plugged my portable air compressor into the 12v outlet on my 2008 Prius and went to pump up my bicycle tires. I new my battery was a little weak (had to boost once after leaving the interior lights on for a few hours) but was surprised that pumping up two bike tires pretty well ran my battery flat. A quick boost (there are spots for jumper cables under the hood) got the car running and I was off shopping for a new battery.

I picked up an Optima DS46B24R -- an AGM battery made specifically for the Prius. It even includes a little vent hole in the OEM location and a back-saving carry strap. The battery cost CDN $195 with a core exchange at my local battery shop. Shop around -- the other local shop that carried the Optima wanted $275!

There are lots of good instructions on this site or even YouTube on how to R&R a Prius battery, so I won't repeat them here. Once I pulled the old battery out, I realized it was smaller than (not as long as) the Optima. My Prius is a base model without the smart key or a few other gadgets, so Toyota felt a smaller battery would do. Mine lasted 6 years, so I'm not complaining. The OEM battery is a sealed lead/acid battery, not a gel-cell or AGM unit.

Getting the larger Optima into the space that the smaller OEM battery occupied is possible, but a bit of a kludge. I didn't want to leave it like that, so I did a bit of research on this site and learned that there is a different battery tray used with the larger battery. My Toyota dealer had one in stock (Part number is 74440-47020) so I picked it up and re-did the battery install with the correct tray today.

I've learned lots from this site and thought someone else might benefit from my story (and small collection of part numbers) -- hence this post. I've also included a few photos comparing the old battery to new and old battery tray to new.

Cheers!