Rookie question -- check engine light "inspect battery"

You can buy a brand new Toyota for a generation 3 Prius from Toyota without any problem You want to buy the battery from your local dealer online and have it sent to the store this way you'll get the most inexpensive price if you walk into the parts counter in New Hampshire be prepared to pay $2,500 if you buy it on Toyota's website and have it sent to the store whichever one it is that you live near it should be more in the 16 1785 range Go look and see post back and tell us or you can spend the $2,100 and get a project lithium battery which is sold right here by the people who make it or whatever see Prius camper. So there will be no problems getting a battery getting a good diagnosis could be a problem realizing that the car is a I don't know what it said above 2010 2011 realize that battery is past the 8 to 10 year normal window of a Prius battery so there's always that so figure the car is going to need a battery now whether you want to play around with these aftermarket the green beans and the all these companies that rebuild batteries or do you just want to get a new battery that's going to go the 8 to 10 again if he's not one to be having wrecks and carrying on on the road go with the new battery you'll be happy you did also be ready for the brakes to do funny business and the brake parts are going to be about $1,700 when it becomes time so just get geared up and ready for this or not If these two repairs will put you out of the car then start looking for a Yaris or a Corolla because you may not need the extra expense for the seven or eight miles to the gallon savings It does cost money to save fuel We personally got out of the generation threes or on our way out now they are not very good on any kind of ROI it's just not there but if you're already stuck in the car there's always that It can be dealt with You just have to know when to stop throwing money at this series of car It's a good car it just has some problems that are costly especially now with what's happened to Labor rates and quality of work and all sorts of things It's easy to get taken by people that claim to know what they're doing.

 

It might have been “check hybrid system”, which is a near-generic message, that pops up for any and all. There should be codes, and getting them will hopefully shed light. Post them here.

 

Welcome!
If it is the battery, call around to dealers for competitive prices, they have new batteries.
Unfortunately, the 2010-2015 generation Prius have multiple weak points, and you should weigh repair costs vs finding another car.
You may run into head gasket problems and brake actuator failure which can run $5-10,000. In repairs

 

Yeah I’m trying to restrain myself, but your grandsons car is overdue for EGR (Exhaust Gas Recirculation) system cleaning (including intake manifold), due to it’s propensity to clog up with carbon.

Head gasket failure happens quite reliably around 150~200k miles, and EGR carbon clogging goes hand-in-hand.

Toyota naturally downplays a connection, and they have some support here. My tact is more chauvinistic: I want my car to last, without a major mechanical headache, so periodically clean the system.

anyway, see first two links in my signature for more info. On a phone turn it landscape for to see signatures.

btw, my grandson (19 years old) came by yesterday with his recent acquisition, a 92 civic, to look over the brakes. It’s got a few issues, CV joint and steering tie rod both with boots letting go, and cam timing belt change likely well overdue. All of that is too much for us, best left to pros. I can help with some stuff though, and will. Just a milestone, when your grandkids are driving.

We even toyed with selling him our 2010 Prius, packing in this game called cars, but dang it we’re not there yet. Will hold that thought though.

 

^ This.

Once you have the codes, if one of them is the "you need a battery" code, you'll know that. There are also a couple hundred other codes. You could have one of them instead.

 

Yeah site’s file upload function is broken, for about a couple of weeks now.

I had a brake “communication” problem some years back (likely due to Scangauge I had constantly plugged into OBD port), and it displayed CHECK HYBRID SYSTEM constantly. Still drivable but no fun; brakes were kinda “work to rule”. Went straight to dealership, was ok.

Try driving quiet side streets first, see if anything feels unusual?

 

When those lights come on, it means that there are diagnostic trouble codes stored in the car to help determine what problem(s) may exist.

So, a good next step is to read those trouble codes. Posting them here will allow people to help.

 

Anything regularly plugged into the OBD port? That's what triggered mine.

 

Ailing inverter coolant pump might be a factor.

Also, 3rd gens had a recall, involved a software update for hard acceleration, which could cause some soldered connections within the inverter to fail. That was only up to a certain VIN as I recall.

 

Those codes aren't about the battery. All those things are in the inverter assembly under the hood, which I believe is covered under a warranty extension that was originally for unlimited miles and 15 years, and was recently extended to unlimited miles and 20 years. Don't clear the codes (they are what qualify you for the coverage). Talk with a Toyota dealer.

 

The inverter is an integral part of the Prius 'transmission'. I mean, obviously it's in a separate box and isn't made of oily gears, but the power being 'transmitted' from the engine to the wheels has to go through it just the same. Depending on what sections of the inverter are damaged and how damaged they are, you can be driving in a 'limp' mode, or just not going anywhere.

If the car will move at all and there's a dealer nearby, you can give that a try. Otherwise, you might end up arranging a tow to get there. Or you might anyway.

 

First I've heard of it, sorry to say. I don't remember ever seeing that in the manual (owner's or repair). Doesn't mean I couldn't have missed it....

If that's easy, and covered, it'd save you some worries about surprises on the way.

Right. In general, the term "inverter" means a gizmo that takes DC power in at some voltage, and produces AC out, at some frequency and some possibly different voltage. The one you're thinking of is just an inverter built to take 12 V DC in and produce one constant 120 Vrms 60 Hz wave out.

A Gen 3 Prius transmission has two motor/generators in it, each one having three phase windings. Each MG gets its own inverter (though both of these are inside the box we usually just call "the inverter"), and each of those is built to take up to 650 VDC in and produce three waves of changeable voltage and frequency out, to drive the three windings of its MG.

Where, you may ask, does that 650 VDC input come from? Well, both MG inverters in the Prius can do a trick your familiar 12VDC to 120VAC inverter can't: they can work backwards. Each one can take controlled sips from its three AC "output" MG windings and lay them down in the right order and polarity on its DC "input". Like rectifying with diodes, but with control. By changing the width and timing of sips, it can decide how much that MG is allowed to generate, and put that amount of power onto the 650 VDC bus that is the common "input" of both inverters. The other MG inverter can then act like a normal inverter and take that power from the DC input and make AC output to drive its own MG. The AC frequency is changeable because it has to match the rotation of the MG.

So the usual thing happening in the transmission is that one of the MGs is acting as a generator, that power is being "un-inverted" onto the DC bus, and then being inverted to power the other MG. In the simplest case, MG1 is the one generating, powered by the engine, and MG2 is motoring, delivering power to the wheels. (There's also a case during higher-speed cruise where MG2 generates and MG1 motors; that one takes a little extra thinking about, but it works out right for those conditions.)

That isn't all that's happening, though (if it were, the Prius would be a "series hybrid"). At the same time, there is some power flowing mechanically through the transmission, without being converted to electricity and back.

However, that mechanical path depends on the electrical path. "Neutral" in a Prius is just when neither MG inverter is doing anything, so there's no electrical power flow, and when that isn't happening, the mechanical power flow is also effectively nil. So the inverter(s) really must be seen as essential to the power flow in the transmission.

I didn't say anything about the battery yet. Its voltage is lower than 650 VDC, so there is also a "boost converter' inside the inverter box, just to convert between different DC voltages. Whenever the car wants to send more power to one MG than the other MG is generating, it can take some from the battery, boost its voltage up, and add that contribution. Sometimes the boost converter is the part of the "inverter assembly" that conks out, which is ok, 'cause the extended warranty covers it too.

The boost converter can also work backwards (purists would call it a "buck converter" then, but Toyota doesn't bother), so whenever one MG is generating more than needed to motor the other (say, when slowing the car), the excess can be bucked down to the battery voltage and stored in the battery.

Depending on how curious you are about the operating principles, you can go about as deep as you want. As an introduction, the model Niels made in Blender is really good.

Just how those inverters control those motors is the kind of thing that can be explained in a range of ways, each way being "right" for a different level of interest, starting with "well, they take the DC and flip the polarity with transistor switches" at the simple end, up through a ten minute video from Mathworks, up through an hourlong video from TI, and every one of those could be called a fair description for a certain level of detail and audience interest.

The TI video is great if you've got the time, but the ten-minute Mathworks one is pretty good. And it has a companion video that picks up where it leaves off and shows how that really can be done with transistors that only switch on and off.

It's kind of neat that you can start out all oversimplified with "all we do is flip the polarity", and then you go into all kinds of three-phase AC messiness, and then you get the transforms that let you look at all that in the reference frame that moves with the rotor, and you end up back where you can say "see? all we did was flip the polarity!"

Those mathy transforms are thanks to Robert Park (published 1929) and Edith Clarke (published 1937/38, first woman to be professionally employed as an electrical engineer in the United States), if you happen to care. I think it's cool.