These are the codes from code reader

jg,

Although I have no firsthand experience, I would avoid the towing method of charging. With just a small amount of pondering, you would need to tow the car while it was in "drive" in order to even have a chance of charging the HV battery. The car will not charge the battery if in neutral. The car must be in "Ready" state in order to be shifted out of neutral. But, the car will not go into "ready" state in it's current condition due to the low HV battery charge (assuming no other issues). Plus, there are too many expensive parts for me to consider that as a viable option.

Your easiest option would be to obtain a high voltage charger like the Prolong unit (or any grid charger for a 202v HV battery), connect the harness and let it charge. Next option would be to charge each module individually using smaller hobby chargers. Decent one can be had for about 150-200 $$ and can do 4 at a time.

 

How would towing even charge unless you were also using the regenerative braking?
The only 2 ways to charge are the engine using MG1 or regenerative braking using MG2.

 

@jgfinley since you like to play with voltage and still have a DIY streak, you might find this thread of interest:

P1080, P3022 | Page 2 | PriusChat

And others have also built HV chargers out of LED power supplies for cheap, if you want to try that path.

 

You can but it will take awhile to charge all of the modules individually.

 

Be very careful with your amperage when charging the modules. Do not use greater than 350 mA once you go outside the 40% - 80% SoC range. I believe this equates to ~1.28 - 1.36 V/cell or 7.68 V - 8.16 V per module.

You want to charge the modules until it stops rising (at around 8.44 V) and then continue the charge for 4-6 hours to top balance each module properly.

 

OK, it's easy to check/verify the 12v health so it's not bad advice but it really has nothing to do with a P0A80 code.

We know 12v lead acid batts typically have a 3-6 year lifespan so every gen 2 on the planet went through a weak/failed 12v battery years ago (and maybe even a 2nd or 3rd time). Most of those 12v issues reported here were evident from the SKS getting flaky, no starts, completely dead car, etc. What we didn't see was a rash of P0A80 codes, trouble lights, etc during those early years because the HV batts were still quite healthy.

 

188 volts is too low for the car to start and is way outside the 40%- 80% range the ca uses. 201.6 V is the nominal voltage of the pack but is also at the low end. The pack is used in the 215 V - 235 V range, but can go higher in use.

11.9 is a hairs breadth of totally flat, so the advice the advice to charge up is solid advice. A full Prius (AGM) battery should be in the region of 12.-13.2 V.

Good solid general battery housekeeping advice.

It is time for this oft repeated urban legend to be consign to the annuls of history. Just because it is repeated (often) does not make it true.

The 12 V bus voltage needs to drop below 10.5 V before it becomes a problem in some of the computers and south of 9 V in others. Therefore 11.9 V is not going to have any detrimental effect. Yes, it is flat and needs to be charged up, but that is a side issue.

 

This. In general, as in any other car, the 12 volt battery can cause you all the usual kinds of headaches, if it is so low that it's obvious without arguing about multimeter readings. You know, locks-won't-unlock low. Lights-glow-feeble-orange low. That kind of low.

The idea that a 12 volt battery at a volt or two below nominal invalidates your trouble codes by making the ECUs "confused" and their diagnostic reports "random" is one of those odd notions that circulates so vigorously on PriusChat that you'd assume there must be plenty of substantiated examples ... until you start searching the forums looking for them, and notice that there aren't.

-Chap

 

It is NOT an urban legend because............

From just reading text messages in a place like this, we don't KNOW under what conditions the battery voltage is being checked.......and in some cases, the OP doesn't seem capable of actually doing a check at all.

If a reading of 11.9 is seen under no load conditions, when subjected to any load at all it may not be able to supply the current necessary current and drop even farther.

This is not just speculation. I've been doing this electronics thing for a bit over 50 years now........and trying to "fix" a problem reported by an on-board computer without first being positively sure that the power supply is healthy and stable......is just a fools errand.

But you are certainly welcome to be foolish if you want. Sometimes it works out just fine. Other times not.

 

Doesn't sound like the engine actually started to keep the HV battery charged.. any codes thrown?

 

No one is disputing that if a no/low load voltage is 11.9 V then when then car has load applied will drag the voltage lower. What is speculation is how low the voltage goes and then the leap that that voltage is the cause of the problems. In your 50 years of doing the electronics thing, how many years do you have with Gen 2 Prius ECUs? What are the voltage thresholds where there will be problems? Just answering these question would add value to the discussion. Unless you can answer these with any accuracy, you ARE speculating and therefore perpetuating the urban legend.

Again, no one is saying otherwise. What we are trying to highlight that in a lot of cases the 12 V is proved to be healthy (enough to do the job) and stable, yet people will not let it go and move on.

 

I did notice also that was the second "50 years" reference in a single week. There's certainly nothing wrong with experience. Indeed, one of the coolest things about PriusChat (maybe even among other car enthusiast forums) is the sheer concentration of members here with similar qualifications.

That makes it a pretty good crowd to have for an audience, in a way; it means as long as you're bringing sources and data and participating respectfully in reasoning things out, people tend to recognize your chops and credibility in the natural course of things, with not a lot of need for drum banging.

-Chap