As a hybrid vehicle, the battery on the Toyota Prius is just as important as its gas tank, providing an equal measure of mobilizing power in addition to all the usual things a car battery does like power the lights and trip the engine starter. Compared to a lot of battery-operated devices widely utilized these days, the Prius's battery is surprisingly hearty, able to last about eight to 10 years, or around 150,000 miles. Unfortunately, no matter how hearty a battery is, it will fail eventually.
Normally, when you experience a severe parts failure in your car, the obvious solution is to take it to a licensed mechanic and shell out for parts and labor. If you consider yourself a handy individual, though, you may be tempted to forgo the mechanic and attempt to replace your Prius' battery all on your own. This is technically possible, but the real question is whether or not it's a good idea.
Potential for danger
Replacing a full car battery, especially one as heavily used as a hybrid battery, is nothing like replacing the battery in your TV remote. It is an extremely delicate, complex process, and, if approached incorrectly, there is a very real risk of electrocution and severe injury. Unless you are an extremely experienced D.I.Y. expert, any money you might save isn't worth the potential for harm.
Toyota doesn't offer official documentation for replacing a Prius battery home, likely because they'd rather not be liable for people who try on their own and get injured. As such, if you wanted to do this, you'd need to consult a D.I.Y. manual or video, which may be out of date or just flat-out wrong. Also, in the event something goes wrong with a replacement at a licensed garage, they'll usually provide compensation and replacements free of charge. If you do it yourself, you're not getting any do-overs in the event of a hiccup.
Money saved, money wasted
Even assuming you're confident in your mechanic skills, there's another major concern when it comes to replacing a Prius battery: cost. The goal of doing this yourself is to save money that would normally be spent on parts and labor at the garage, but there are many potential ways that doing it yourself could end up costing you more than you'd save.
Labor notwithstanding, replacing a Prius battery can cost anywhere from $1,000 to $4,500 depending on your Prius's exact make and model. You might be able to veer toward the lower end of that range if you buy a refurbished battery, but that's a big gamble. Refurbishing batteries is a tricky process, and if they're not prepared properly by an expert, they can swiftly fail right after installation, necessitating further costs for another replacement. Additionally, if you happen to make some sort of mistake in the process of hooking up your new battery, you could cause damage to your Prius's electrical system, which means more money for repairs.
It is possible to replace your Prius battery on your own, and if you manage to do it perfectly, then yes, you could save at least a few thousand dollars. However, that potential for injury, damage, and lost money must not be ignored. If you're not 100% confident in one or more of these factors, you'll want to stick with your local or a certified Toyota mechanic.