2010 - replaced 12v battery - problems ensue

Hi all. So we have a US 2010 Prius with us in France and we are moving back to the US. (Employer pays for moving the car around so that’s why we do it this way.)

In preparation for the trip back to the US, I thought it would be smart to replace the 12v battery, which is at least 6-7 years old.

Got it replaced today for a Varta A15 - which retails for like €40. I called the shop to say this doesn’t sound right as Prius 12v batteries are expensive. He insists it’s correct. So fine.

Got the car home today (40 minutes on the highway) and I realize the traction battery gauge is showing 2 bars. This is not normal.

I start the car and sit in the driveway with AC on. It blows AC with the engine off even though the battery indicator is low.

I drive it around and it stays mostly at 2 bars. After 10 minutes and a lot of intentional regeneration, I get it up to 6-7 bars. Then I start driving normally and it drops after a while to 2.

So I plug in my Carista ODB thing and fire up Dr Prius and it says the inverter is warm. I try a full battery test but can’t get past 80% and then after some fussing around, realize the inverter is showing warm in the Dr Prius app.

So then I look at the battery and notice it’s a Varta A15, which doesn’t show up as a Prius battery on the Varta website.

Could the wrong 12v battery cause the traction battery not to charge or the inverter to get warm?

ODB reader showed no codes or errors and there are no dash warning lights. Even after letting it sit an hour, the motor stays off even when AC is on and 2 bars are showing on the battery gauge.

TL;DR - shop installed possibly crap 12v battery and now traction battery won’t charge and inverter is warm - why?

 

I can get a voltmeter and yes I can disconnect the battery. In fact the battery vent is not connected correctly anyway so I’m going tk have to reconnect it.

Does a 40€ battery sound plausible? I thought they were more like 150-200?

 

What does this mean?

 

Ok, somebody mentioned it could be as simple as the computer relearning the state of the traction battery after having been disconnected.

This seems to have been the correct answer. The behavior was indeed pretty weird but after 45 minutes the display and the behavior of the battery were in sync and everything was fine.

I am glad to hear the battery specs aren’t super specialized.

The inverter was showing as too warm because of the Dr Prius battery test I did. Still haven’t figured that out but it’s a problem for another day.

Thanks all for the help.