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No warning lights means you might be able to make your battery healthy again via reconditioning, which is 3 progressively deeper discharges and recharges, which breaks up all the poorly conducting crystallization inside the pack. Maxx-Volts and Hybrid Automotive sell systems to do this.

As for your battery cooling fan, they're a rarely used fan in these cars so it's a flat out lie that it was worn out. But it does seems to be increasingly common for dishonest mechanics to make a few hundred swapping it out with one they already cleaned, but honest folks like myself simply charge $20-$30 to clean it because it take less than an hour. A very easy DIY project to do yourself too.

 

"Refurbished" battery deals are mostly a BAD investment, bordering on a scam.
You have been taken in twice now.
I suggest that you STOP doing that.

At this point, however, you should go back to the place that sold you the most recent battery to see if they can pinpoint the problem.

In ALL of this time, has the 12 V battery been replaced ?
If not, it is probably overdue and could be part of the problem.

 

It’s an after market battery joint. Who is it? Doesnt matter they all suck.
They just replace the cells that have gone bad with the same crappy old vintage cells that have just not failed yet. Same 14 year old cells.

Meanwhile your driving around with a 16 year old battery with whacked cells dreading the red triangle of death.

They do not sell new toyota replacement cells. Only way to get those is buy a new complete battery from the dealer. very pricey.

These guys honored the warranty then drilled you for a fake fan repair to cover there cost. You got to know that fan job was baloney...

We call it Whack a mole battery repair it is the biggest scam going.

Get used to this Chinese fire drill battery replacement meanwhile your car will run like crap the whole time. A Prius G2 is an annoying go kart without a healthy hybrid battery.

We see this hundreds of times on this site. Craig's List whackers. Start reading all the g2 forums
Concerning hybrid battery’s. Everyone’s g2 battery including mine is dying from lack of driving
and just plain age. Its 16 years old. You ever see a battery sixteen years old that lives in the trunk of a car? That's some high quality engineering there.

Since I could not find the $1600 new Toyota battery people say are all over I went with the new innovative brand new cylindrical cells as a total battery replacement. A long time PC engineer reps them on this site.Been about 6 months so far they work exceptionally well. $1600 delivered. You install. The alternatives are ugly.

http://newpriusbatteries.com/

good luck.

 

get a corolla or some such

 

Bisco---lol...really. I bought a 2017 Optima EX NO BATTERY lol... need a break from the battery crap. It gets 30 mpgs and rides like a dream.

My 2007 new NPB battery is running good though mama is happy as she crashes and bashes her way around town in it.

 

I also went the route of replacing the modules with the ones from NewPriusBatteries.com back in October. Due to the pandemic, I'm not driving as much as I used to, but I've got about 1500 miles on the new battery pack so far and have had no problems. Not only does the car drive well, it actually accelerates like it did when it was new. Time will tell about longevity, but so far I'm pleased. Several others on here were more early adopters, and they all seem to be satisfied.

There was one person who said that his mileage went down, but he also said that he put an awful lot of air in his tires, and drove 80-90 mph on the highway. I didn't put a lot of faith in his testimonial.

Good luck with your car, I'm sorry to hear that you were taken advantage of by the rebuilt battery guys.

[EDIT] Didn't seem too helpful to rely on memory about the guy who didn't like the NewPriusBatteries. He said that his mileage was about 40-41 mpg after putting them in and that he tried putting 80 psi in the tires to get the mpg up, but that didn't help. (I'm surprised they held that much air). He then said that he could drive slow or 90 mph on the highway and his mileage wouldn't change. That seemed suspicious since even an aerodynamic car like the Prius would have a lot of drag at that speed, definitely resulting in even lower mileage. It's apparent that he drives his car hard, and could have had any number of issues resulting in bad performance. Other than that one guy, everyone else on this site seems pleased. Be advised though, the NPB are not a replacement battery pack, but a kit to replace all the old modules in your existing pack. It comes with everything you need including new hardware and wiring harness. It's not a plug and play swap, but it wasn't too hard either if you take your time, and it's helpful to have someone help you get the battery pack out of the car and get it back in when you're done.

 

I always wanted to drive a SomeSuch

They make great cars! Hope they make an EV version some day!

 

Mine with the combo of the new battery and the Red Bullet VVT solenoid hauls a little bit of butt actually. It's fun to drive now.
Its got power at that pass another car band it never had before.

My NPB battery's are freaky they just sit at all blue or green bars consistently which is odd because mama just trucks around town mostly no long hiway drives.

Its been so many years I cant remember if its like that when it was new always green it was so long ago. Amazing how time fly's. I now own a 14 year old car lol....and it runs pretty good.

 

16 years, 3 pri, all ran around 6 bars average

 

Due to this: So no warning lights on the dash are on or anything.

You likely have something else going on that is causing the battery to drain. It sounds to me like you probably have weak engine output, or something causing extreme drag on the car. The battery is trying to help the engine maintain speed and is just draining itself. Any time the battery gets down into two bars or less, a gen 2 acts like a dog until it charges the battery back to 3 or 4 bars. You can see this in the battery control limits. So basically, you're getting the car caught in a loop. Battery drains trying to help maintain speed, engine revving, but making no power, unable to actually recharge battery correctly. Maybe you have a mouse nest in the intake piping, or a stuck parking brake, or......

But I'm just guessin'........

 

That's alot of bars to visit in one night... I'm lucky if i can make it to the second bar because I've always had a three drink limit!

But it makes sense, professional cookie crumblers are known to keep the party going till the sun comes up.