Started my Prius after 17 day vacation, error P080A

How old is your 12 V battery, and have you checked its voltage?

If the 12V is okay, consider that your hybrid battery is twelve years old. That's not a bad life. It's probably time to replace it if you'd like to keep the car running for more than a year or two.

A shorter-lived and cheaper option is to buy a remanufactured battery, but it will use modules of the same vintage. Some hobbyists will rebuild, recondition, and rebalance their own packs for a great savings, but it takes time and commitment, and that that point the Prius becomes a project or hobby car.

Your OBD reader may not be seeing all the Prius-specific codes if it's not a Toyota product. There may be more information about cell voltages and temperatures, etc.

 

how many miles on her?

 

13.5 is the wrong measurement. you need to test it after the car has been off for a few hours.

unfortunately, a battery living on the edge can be put over by non use. if it turns out to be a bad hybrid battery, and you can only afford high mileage cars, i would agree that a hybrid may not be your best choice.
all the best!

 

Knowing that my car will sit for any length of time (more than a week) without use, I will attach a trickle-charger to the battery. If the battery is near 5 years old, then I'll replace it.

I have never been stranded by a bad battery.

 

You posted P080A correct?

Bad hybrid battery is P0A80

If it is in fact P080A you may have inadvertently pulled one of the wires out of the positive battery terminal block by the 12v battery when you disconnected it.

 

I was going to say that 13.5 volts with car running is pretty weird. It should be about 14 or 14.1 running. But Todd may have hit on it. I wonder if she disconnected the positive and accidentally pulled out that wire. Standard procedure is to disconnect the negative first and, in this case, only the negative.

 

Yes. This has now happened to me twice on my 06. Sitting for long periods of time will send a tired HV battery into fault mode. P0A80 A grid charger "may" save the failing module(s) or may not. Your options are: replace the failed module(s) with used, good ones, replace the battery with a rebuilt (refurbished) used one, or a new Toyota battery.

 

Not really, 13.5 V is acceptable in READY, it just means the 12 V battery is at the FULL end of SOC. 14.1-14.4 V means the battery is at the low to empty end of SOC.

She is a he.

 

Oops. Thanks for the correction. I missed that she connected, but MB31 was the one who disconnected. But the point remains.

I have never seen a Prius charging system put out less than 14 volts, but I only work on my own cars so my experience isn't that broad. All I know is at all four of mine have shown 14-14.1 in ready mode every time I checked. Hence my assumption that 13.5 was odd. But, if the code is actually P080A, all that is moot. When I googled that code, I discovered that a lot of people move that "A" around and still come up with "replace hybrid battery pack." A common typo, apparently.

 

if your po80a is a dyslectic P0A80, you can test the hybrid battery with a prius aware obd2 reader, or have the dealer do it.

 

Sorry about your accident. Hope you heal quickly.

My next step would be a load test on that 12V battery. I'm pretty sure it will fail. In our country, almost any parts store can do that for free.

 

why is 11.7 good in accessory mode?

 

if it's more than 4-5 years old, yes. if not, you can invest in a smart charger, but there's no guarantee it will hold a charge.
a good battery should hold 12.4 volts or better, overnight.

 

Keep in mind Gen2 will run down the 12v on standing, unless you remember to turn off the SKS smart key system before you park.
17-days is pretty long so maybe it has recovered since then.

 

First let me say that the 12V battery is probably a bit weak, but unrelated to the actual HV battery failure.

It sounds like the HV battery might have been marginal from the get go. Leaving it for 17 days definitely shouldn't kill a healthy battery, but a weak battery might lose some charge while sitting, and then it can take a while before it recalibrates to the new charge level (which would typically look like an abrupt drop of several bars of displayed SOC, down to the purple/red bars). If the battery is already weak then the SOC often gets out of kilter anyway, then being unused for those 17 days would have made it worse.

When the Prius first starts it initially (while cold) uses the HV battery almost exclusively for motive power (in addition to powering the DC-DC converter and charging the 12v battery and other electrical loads). So the first minute or so is really hard on the HV battery! Couple that with the battery ECU not having recalibrated (so the Prius probably doesn't yet "know" the the SOC is critically low at this point) and that is what killed the battery.

I would strongly recommend that anyone else in the same situation (old Prius with possibly weak cells and left undriven for some time) to start it up and just leave it in "P" and let it idle (which gently precharges the HV battery slightly), until the engine cuts out, before doing anything else. Perhaps even consider force charging it (foot on the brake and accelerator with engine at moderate revs) for another minute or so after that before driving off.