Hello all.
I just had a 12 volt battery issue with one of these vehicles here at the company I work for. This may cover some topics that are on some previous comments but might be helpful all in one big pile. I apologize for the length of this post, but hopefully it will put some pieces together if somebody is having a version of the same issue. The boss's launch model r1t was parked with 60 miles left on the battery at my shop here in Washington state with a flat tire. It sat not plugged in and without the fob in the vehicle in 20-35 degree weather for about 6 days. When I got time to repair the tire, it would not respond to the fob or any amount of screaming. The door handles were not in a welcoming position nor would the front trunk lid or the charging door respond to any commands. I then pulled the jumper wires out of the round port to the right of the receiver and connected a battery charger to them. Still no luck but I could hear some actuators trying to come to life. I then took a gel cell 12 volt optima battery and connected it to the wires and tried again with the same luck. I put the charger on the battery and walked away for about three hours and when I came back to it with the fob, the door handles opened up and let me in but I couldn't get the charge door or the trunk lid open. The dash display was showing alarms, 0 miles on the odometer and actuators were buzzing due to the low voltage situation I assume. I tried to pop the trunk with the button on the RH side of the grille and the fob with no luck. I left the battery and the charger on a 40 amp charge for a total of about 5 hours that day and had no luck getting the charge door or the trunk open. That night I turned the charger down to 10 amp charge and left it and the optima battery connected all night. The next morning the optima was completely flat and the charger was going full cheese on the meter with no response to the fob again. I removed the optima battery and took it inside and revived it. I reconnected it and tried it all again with the same results. I got on the phone with Rivian support and discussed what the situation was and what I had done. The support representative told me that the 12 volts batteries are dead and need to be replaced at one of their service centers at the tune of $1250 (if I could drive it there, huh...). Also that it would be the customer's cost due to it not being plugged in within that idle timeframe with the state of charge that it was left in. I asked the representative what happens if it gets left at the airport for a 2 week sales trip. The representative said that it needs to be put on a maintenance charge while not in use for a extended duration. I asked how to get the vehicle's parking brakes off to roll it on a trailer and after consulting an associate the representative advised to put the vehicle on rollers to load on a trailer or tow vehicle. After repairing the rear tire, it looks like there is an actuator on the brake caliper that applies at least the rear brakes when in park (fyi).
We were able to get a ex Rivian tech that lives in the area to come by and see what he could do before we hauled it 4.5 hours one way to the closest service center and threw batteries at it. He had better luck getting the trunk open than I did with the fob, but the cabin doors wouldn't open for him. It must only consider me a friend... He pulled the plastic cover just to the rear of the trunk tub off and pulled the cabin air filter plenum off to the side. He removed two 10mm head bolts out that holds the back of the tub in place and shimmed the backside of the tub with a 2x4 forward to give some room to the 12 volt power distribution banks. Once the red plastic covers were removed from those banks, he was able to connect two jumper packs to the banks (see picture below)
. One to each bank, one on the left and one on the right. This gave enough line voltage to get the controllers to wake up and allow the charge door to open in it's Lambo style. Once it was open, we were able to connect the travel charger and let it sit over the weekend. This gave it enough charge to have everything come on line and drive it into the shop to warm up and charge some more. Even then, it still had a electric motor code, but that went away once it was fully charged and was driven a little bit. The 12 volt batteries seem to be fine and all of the functions seem to be good but time will tell. The owner and I were talking about it and came to the conclusion that it bleeds about 10 miles of charge a day while it sits. Maybe that is better when the batteries are at a higher state of charge, or maybe not.