strange things with electrics!

Sounds like you have a poltergeist

Seriously though, you don't have any teenage kids do you? Who might just happen to borrow your car without your knowledge?

 

Not sure about the radio, but if you have the HVAC system on auto, when you change the temperature the computer will kick in the AC under some conditions.

However, the most common issue is the 12V battery might be going. This has been known to cause the most bizarre happenings as documented in a large number of threads on this board.

 

There is also the remote possibility of a fault or short in the electrical system.

 

A 'smart card'? Do you mean a Smart Key? Prius' with the smart key, if left for lengthy periods (like on a showroom floor) could drain the 12v battery, potentially damaging it. The dealer should disable the Smart Key system (switch under the steering column).

A new battery would not push too much voltage and shouldn't damage anything. Batteries usually go the other way - reducing voltage as they die.

 

There is no direct drop-in substitute for the Toyota battery. Get the correct battery with the correct original cables. If the dealer did some hacking to make an incorrect battery fit anything could happen because of poor or intermittent contact.

 

The battery intended for SKS cars is larger capacity tho, correct? If there's nothing wrong with how it can be installed I'd probably prefer one.

- D

 

It is unlikely that a battery with larger capacity (CCA) could be worse. It should be the other way around.

I would check the connectors of the battery. A loose connector could cause random reset depending on surrounding humidity and vibration, etc. If anything, tighten the connectors, which only benfits, no harm.

 

There is no possible way for an "incorrect" 12V battery to damage the circuits in your car.

 

Unless somehow the connectors were not seated well. The advice I got was to loosen the connectors a little bit, make sure they seat well, then tighten.

 

I wasn't aware the GII Prius has two different sized 12V batteries. I thought they all use the same one?

The GI Prius DOES have two different size 12V batteries.

 

G2 has two different battery sizes. The smaller one, 28Ah capacity, is for Prius w/o Smart Entry / Smart Start. The physical size is the same as the Classic original equipment GS battery; the only difference is that the battery terminal polarity is reversed.

The larger battery, ~35Ah, is for Prius w/ Smart Entry / Smart Start.

 

The installation instructions for an Optima Yellow Top battery I saw on here note that there is little clearance for one of the terminals. If the wrong battery was installed, this might cause grounding issues?