HV Battery is Losing Charge Quickly

Hi Allen, You're learning a lot about this car. I strongly recommend techstream in order to get all the codes and details. I'd also suggest clearing any and all codes (after noting what codes you had with techstream) by disconnecting the 12V bat for a few minutes. If you have faulty charging system component(s) techstream should tell you this.

Do you have access where you live to junkyards with a lot of Priuses? If so you can probably find a relatively low mileage salvage battery and try that. Only problem is that some junkyards think their salvage batteries are worth a lot. With some research on PriusChat you can locate a new battery for not a crazy amount of money.

I would also ensure that you fully charge your 12 v bat with a charger.

After that I'd just drive the car until you get codes and not worry too much about indications. If you really do have a bad HV bat it's possible at some point it will discharge too much for it to start the ICE. This can be fairly easily resolved temporarily by making yourself a "grid charger" and recharging the HV bat enough to start the ICE.

If the seller of the HV bat you have now won't co-operate with you then you have to decide how far you want to fight with them.

But as you've seen, people on here much smarter than me are not convinced you have a bad HV bat.

Good luck.

 

As I understand it, a "real" test of the 12V bat requires it to be load tested. Most typically have it done for free by autozone

A HV bat for $89 sounds too good to be true (or too old and worthless) $400 is pretty cheap. In LA I've paid $800 for an HV bat with about 60k miles on it.

You can search PriusChat for grid chargers. Many use Mean Well LED drivers, which cost around $50, a few short battery cables, a switch (or a diode), and a male 110v plug.

Techstream is the official Toyota diagnostic software/code reader. As I said above, mini VCI cables can be bought on Amazon, and techstream and a hack for it can be downloaded.

Anything is possible but I'd say the wheel bearing is unlikely to be creating your issue.

Good luck

 

all 3 of my pri go between 2 and full bars

 

yup, that's a problem. i can't understand why you're not getting a code for those cells though

 

Hi Allen,
Yes, I agree with you and bisco after this test result. You might find techstream gives you more in depth information. But it seems you do have a battery issue as you've said all along. Your challenge is clearly what to do about it. If the seller creates roadblocks to their addressing this then your options are somewhat limited: you can pressure them further (your transaction with them will not be good publicity for their company), you can try to "refurbish" the battery yourself (you might find replacing blocks 1 and 2 with exchange blocks works, or you might just have bad connections, although any type of refurb is a temporary measure), you can replace the battery with new or another refurb. PriusChat is loaded with options on what you can do. The most conservative, long term solution preferred by some is to replace the HV bat with new. If you do this you can likely sell this old bat for a fair amount because many others are willing to do shorter term refurbs. I don't believe there is any magic solution - ie one which is long term, cheap, easy, and effective. Of course you can also just keep driving the car until you get other codes and more significant failures. Good luck.