Advice after replacing first hybrid battery? (2002, 139k miles)

Last Friday, I got a turtle light on my 2002 Prius (which has less than 139,000 miles on it but which is nearly 21 years old with the original hybrid battery). I was in San Francisco at the time and decided to drive to Luscious Garage to get it checked out, and noticed that the car felt sluggish at times. (I had also noticed for a few months that the hybrid battery seemed to jump from nearly discharged to full very quickly.) The LG mechanic ran a test, which did find that the existing hybrid battery was discharging more quickly compared to a new battery. LG offers a 5 year warranty on a new hybrid battery, even though they simply get this from Toyota, so their warranty is a lot better than Toyota’s is.

(In August, my insurance had paid to replace the stolen catalytic converter and I paid for a shield over it; the CC is also protected by some welded curved iron rods over the visible end. I *hope* that this new protection is good enough to deter thieves. I also took the Prius to a hybrid mechanic about 6 weeks ago, who thought the car was otherwise in pretty good shape.)

I have an appointment tomorrow (Thursday) to replace the hybrid battery as I want to be able to drive long distances with the car and don’t want to risk the current battery failing while I’m on the road.

1) I’ve noticed that my mpg has been dropping down to about 35 mpg. Will replacing the hybrid battery improve that, or is there anything else I should do?

2) Since the current hybrid battery is still functioning, I’ve wondered if it can be repurposed. Any suggestions?

 

Aamdb, good point about the possibility that replacing the hybrid battery may become difficult. I also didn’t want to risk the current battery or a remanufactured aftermarket battery failing during a long drive (I had heard it can take a while to get the new battery.) Even if the new hybrid battery does fail within the first year, I should be able to get it fixed no matter where I am.

You were right that Toyota requires that the “core” be returned. Otherwise, I would have to pay another $1300 if I wanted to keep the old hybrid battery.

Luscious Garage’s price is $3386.91 overall for the labor and cost of the battery. It has the longest warranty of any place I had contacted within the past year: 5 year, 50,000 miles, but of course, one would have to be in the area to utilize the warranty. Still, it’s a good sign that they’ll stand behind their work for that long.

I’m also getting the rear struts replaced since one had leaked its fluid.

Even though there weren’t trouble codes, I had been monitoring the state of the hybrid battery since January. Recently it had started fluctuating a great deal between half-charged and then suddenly zooming up to 100% charged. It had even gone down to about 25%.

The battery was found to go from 65% to 43% state of charge in about 6 minutes. “A healthy battery goes from about 65% to 45% in about 18-20 minutes.”

I’m the original owner but there were a few times when people I’d asked to drive the car still didn’t drive it often enough, and the 12 volt battery died at least three times during my absence, requiring me to replace it with a new one. Those long periods without being driven may have damaged the hybrid battery further. Still lasted over 20 years, though.

Hope this gamble pays off!

I appreciate hearing different opinions about this from everyone here.

Thank you!