I had the same problem which I replied to on another thread, with my 2020 RAV4 hybrid limited. the battery went flat over two days in the garage. So, I read the responses, and I’m sure you have got your problem solved by now. A couple of things though. First, they don’t want you jump starting the battery from the battery location in the back. There is a specific place to hook up under the hood, with the positive terminal of the jumper cable going to the stud in the fuse box on the left side of the engine compartment. The ground point is in the middle of the engine. There is a location diagram in the handbook.
You have to be very careful jumping or just charging the 12 v battery. I did mine last night, after I realized that the battery was flat and that’s why it was telling me the system couldn’t recognize the key fob. To recharge the battery, you have to disconnect the negative wires from the battery. Just take the fitting off the terminal.
To openly the resr door manually, someone has already told you the manual reference. It’s a real pain in the ass to get at, plus it’s hard to figure out just what to lever on with the screwdriver to open it. It took me a while. The drawing in the book is about hopeless. It gets you close and that’s about it.
As far as what made the battery run down: There are at least 10 other folks on this site that have had the same issue, mostly with the gas models. I suspect it’s something not shutting off when the vehicle shuts down. I put a meter over the terminals to check the current draw when the car was shut off. i couldn’t get the little screen in front of the driver to shut off, with the rear door open, so couldn’t get a reading with that screen off, but with it on, it was drawing 1.2 amps. That’s a lot. So, if the System doesn’t shut completely down, you will have a problem. I don’t know for sure what caused my problem, but I do know I didn’t leave any of the doors open or the lights on inside or out. The car sat in the garage for two days. I went out to leave, and the system fired up. Then about the time I was putting it in reverse, the screen shut off, and I had a message that the parking brake was not initialized, and that the key fob couldn’t be identified. I tried another key fob, same messages. When I closed the door, I got 8 beeps out of the security system. I had to attend a meeting so took my other vehicle. When I got home, I noticed that now, the entire vehicle was dark and not lights would come on. I manually opened the rear door and checked the battery. Yep, 5 volts.
I recharged the battery using the toyota procedure in the book, and then reinitialised the hybrid system per the book also, and all was well. There were a couple of systems that took a minute or more to come online, the park assist, and one other, but they all came back and the vehicle is running ok. I checked the battery voltage after three hours and it had not dropped. I wanted to check the current draw with the entire car off, but as I mentioned above, I couldn’t get the system to power all the way down with the back door open. Maybe I didn’t wait long enough??? I thought after 20 mins the vehicle would power off any systems still running. Anyway, I hope this helps. I think Toyota has a gremlin in the system that is not shutting something off. Could be that mini dsplay in front of the driver. I will keep an eye on it.
