car is throwing P0800 and P3011 codes and the elec.motor disconnects from battery

Looks to me like you need to undo the coils plugs and have a look The 300 whatever code you have is talking about cylinder one misfire I believe maybe that plug or all the plugs are just old and near dead that would be a good place to start misfiring is no good and generally in this engine it's not a head gasket or the fire being put out by water it's usually a bad plug failing coil or the plug well is filled with oil from bad valve cover gasket and o rings

 

I don't think P0800 is a code you're getting: that's an SAE standard trouble code for a transfer case, and your car isn't four-wheel-drive and doesn't have one of those.

Once you confirm the code you've actually got (P0A80, maybe?), you can use the Report button to have it changed in your thread title too, which will help other people find the thread.

 

what code reader are you using?

 

IF the HV battery was recently replaced AND you have codes (P0A80? & P3011), then I would look into getting the battery replaced again under warranty.

It's not uncommon to have problems with "refurbished" batteries. At best you might get 2-3 years. Sometimes you get a few months (or even weeks). It all depends on what the "refurbisher" did to the used battery modules before it was sold to you.

The most reliable solution is to get a new battery pack from Toyota.

Posted via the PriusChat mobile app.

 

unfortunately, most won't read complete prius codes because of all the computers.

 

Your HV battery is well over the 10 year limit . Or that's generally the max limit you'll get out of a HV battery in these vehicles some have gone longer but it's certainly not the norm many have been replaced much earlier so there's always these things If that's an original battery it'll have frosted nuts and discolored bus bars and so on and so forth if somebody looks.