NEWBIE 2009 prius, do I need a new battery?

Hello everyone! Happy to be a part of the forums here, I have a few questions. I own a 2009 Prius, 122,000 miles. I got what I felt was a great deal on the car, only paid $3000 out the door from a private lot. Wasn't shopping a hybrid at all, so when this gem popped up and I test drove it, I didn't have a clue what to be looking for. It drive great and was like driving on clouds suspension wise. Now I should mention all of the lights were lit up on the dash. Red triangle of death, tire pressure, check engine, and vsc all on. The touchscreen shows a red car with exclamation in the middle too. I didn't know or really notice too many of them as the dealer originally showed me the car and immediately said it needs tires filled up because of the light. They checked it and said no codes came back at all, weird because of all the lights on.

Bought the car and as I'm on my way home the worst possible thing happens... The engine makes a strange noise and feel as if it was in high "gear" (I know these are cvts), the car seems almost like overworking itself to drive super slow. Acceleration from a stop was 0 to none. Took a full 30 seconds to get to 40mph. The battery from the start of this slowly drained lower and lower and was not recharging as I coasted or was braking. I drove it home freaked out that I bought a lemon.

Next day, works fine. Like nothing happened. Drive it 30 mins, no problem. So I'm thinking maybe idk how to drive this thing etc... But then it happens again, in the middle of driving boom same thing. This time I pull over. Restart and it works fine to get home. Now from my research I have found this is usually either 12v battery, the hybrid battery or some cells within, or the power steering pump? Or leak or some kind not sure. I have ran the 12v self test and it checks out perfect 14.2v under load.

I have ordered a Bluetooth OBD2 Dongle to plug in and I plan on using TORQUE Pro to load custom pips for the Prius gen 2 and see what voltages these individual blocks are putting out from the hybrid battery. Only thing I'm not seeing is a Prius that works sometimes then doesn't other in this manner. If anyone has any clue on these exact problems, maybe I'm close to losing the hybrid battery as a whole and it's just a Toyota hanging on. Let me know what you think, sorry for the semi long post.

 

Thank you so much for the reply. The other bad thing about this Prius, the hood lid doesn't work (yes I bought a car without looking inside the hood lol). But sounds like if it's quiet outside I could hear it. I will try now and report back

 

I did hear it running right behind the drivers side headlight

 

Thanks, if the battery is shot it's not that great of a deal. But yes it's been Carfax checked no accidents, and mileage I would assume is honest at 122k. If the battery is bad I plan on going the cheapest route possible while still covering my butt. I have found an eBay seller who installs battery pack with 3 year warranty for $850. He has great reviews and I think that's the best price I'll find with warranty.

 

I have got the obdii scanner working. Here are the codes I received.

 

This as well

 

So as I observed more I noticed an odd trend. So the voltages look fine except for block 3 as indicated by the code and also the voltage. When in drivable mode the voltage of just block 3 goes down to 14.2 then races up to above the rest at 17.4 or so, then back down. Over and over again. The HP of the electric engine also drops to negative values while this happens. Eventually it goes into "safe mode" revs high and doesn't allow any acceleration or battery/elec engine usage. This is where the batteries all show balanced even block 3 at 17ish volts. As I totes around I cleared engine codes and about half had a heart attack when the car would barely start then die out from low idle... This happened several times and I thought oh crap I screwed it all up. Eventually I learned and hit the gas a bit when it started up, gave it a test ride around the block just fine. Let it sit and idle for 5 mins and it started to die again. So what is going on here... I'm so confused lol could a bad block #3 really cause all of these issues???

 

Oh sorry, die as in stalling out. My bad, rpms drop to like 900 and it starts to go off but by hitting the gas a bit it revved back up. Seemed like a low battery thing. And I'm going to purchase a refurb battery from eBay his user is hybridplusbatteries, he has 411 positive reviews all on just these batteries. Called him on the phone and get a good feeling, also he's pay after install and accepts PayPal so I will purchase through eBay to get buyer protection if need be.

 

Sure, but it will still have the electric motor to work from then. I'm talking about a full shutdown to power off state. No lights in dash. Have to restart with foot on brake. Getting battery replaced Thursday by technician for $850 with an 18 month warranty.

 

I'm sorry if I haven't been super clear. Also these were not driving tests. These were standstill in the parking lot tests. Only drove it to recharge the battery once it started stalling and the only way to keep the car running was to hit the gas.