2008 Prius Hybrid battery drain

Generally I would say your battery's worn out It's like what 20 years old however old the car is old. So there's always that hybrid batteries go from 8 to 10 and a good run that's years If you're on the original you're well past that I have seen cars with 495,000 miles on them with the original battery and they seem to drive fine going back and forth to work I never was able to put the car under any kind of load as I live on flatland etc I was putting a break actuator on the car The car was in good shape other than the miles and it was in very good shape for those miles clean that terrible tan velor interior but clean is a pin women driven college employee very clean but the battery was original as far as the people knew they had had the car since basically knew they don't ever remember having the hybrid battery touched by anybody they put in plenty of 12 volts and plenty of sets of tires but not an HV battery. I have owned cars with failing HV batteries where the fan is running all the time and the ice engine is getting you 37 mi to the gallon and running constantly That's generally where you are when the battery is more or less crapped out and that's that so you're right there near that apparently and like your mag-like flashlight when the duracells are dead you go to the store and buy new ones same with the HV battery It's time to go to the Toyota dealer online order the battery have it sent to the store you'd like to pick it up at and do that or not maybe it's time for a new car.

 

Please provide some history of the hybrid vehicle battery that is in your car.

1. Is it the original OEM from 2008?
2. Has it been repaired by replacing some of the modules?
3. Was the original battery replaced with a refurbished battery?
4. Was the original battery replaced with a new OEM battery?

Based on the answer to these 4 questions, I can give you my guesstimate on what the problem is and some recommendations.

 

you should get a trouble light if it's the battery. might be some corrosion inside

 

I'll go with the assumption you have no codes, so the car thinks it's doing everything right. You have a simple problem. The car engine is not making enough power to move the car >50mph and the car is using battery power to make up the difference.

Find out why the engine isn't making enough power. It needs air, fuel, spark and exhaust. One of those isn't up to par.

It seems sad a shop can't figure it out. Could be something as simple as a mouse nest in the intake duct restricting airflow, or a crushed exhaust pipe not allowing adequate exhaust flow, but this is often accompanied by unusually load exhaust noise due to the backpressure popping the exhaust pipe off the exhaust manifold gasket.

 

I thought my 2006 HV batt might last a long time due gentle cold winters and we have a downhill to the house to charge it up on the way home. But it up and died in February 2020....go figure.

 

It did last a long time as hybrid batteries go generally speaking seriously? I don't know why I would think a battery would last some kind of superior long time just doesn't seem like a thing I mean look at the Tesla batteries catching on fire one or two things going wrong inside and the guy on Rich rebuilds is taking these cars to shop for they're dropping out I don't even know what it is 4,000 lb battery packs special lifts tables oh my God but yeah absolutely now if I got 14 so years I'd be happy and move on 1670 or so for a new battery. So on that 14 years what's your yearly cost for that battery 100 bucks or something certainly nothing to be disappointed about I guess I'd say like do you have to start replacing batteries in your e-bikes and all that stuff proprietary things stuffed and crazy places Big fun.

 

A Prius hybrid battery does not fail and give these symptoms. The battery is working exactly like it should, providing power when needed. Regardless of its age or current capacity, the battery is doing just fine. It's draining because the engine/transaxle is not doing its job of propelling the car and/or recharging the battery. Putting a new battery in that car would be a waste of money because it would drain just like the one currently installed. A key indicator is that it works fine at low speeds, but when more HP is needed, it falls on its face. This isn't even hybrid knowledge, this is basic ICE characteristics aslo.

 

I was first thinking that the HV battery has very low capacity remaining because of its age. But TMR-JWAP is right about the engine not producing enough power. The first three things to check are restricted air intake to the engine, restricted exhaust from the engine, and low fuel pressure/injectors. I am sure there are other things to check, but these three would be at the top of my list. The car has 146k miles, which seems low to have any problems with the engine.