I may have misunderstood, but I remember reading somewhere that the Primes with the larger 11" screen could show the status of the 12V car battery (not the EV battery). What about the Plus trim? (The version with the small 5" screen not the large 11" screen). Is there any way to know the status of the 12V car battery in the Plus trim? I had mine die yet again when left in the garage for maybe 15-20 days. I ordered a trickle charger and jumper for the future because I'm tired of calling AAA to jump it when the battery is still "good", but just wondering if there's a way to actually see the status of the 12V battery (and if I need to charge it or not). Thanks!
Not sure how knowlegable the poster was but I read here that draining the 12V low enough for the Prime to puke probably damaged the battery. Maybe not the first time but if it's happened multiple times the battery may be very problematic in the future. I have a 2018 Prime Advanced (11" screen) and never saw a 12 volt battery status. If it exists I too would like to know where. The only time my car warned me of a low battery was for the key fob. I now change them annually because it's cheap and easy to do.
@stevepea I've got a plus and to the best of my knowledge there is not any way to see the 12 volt batteries voltage or temperature on any of the cars gauges / screens. Techstream software, again to the best of my knowledge, shows both voltage and temperature of the 12 volt battery. It's also possible to get the 12 volt batteries voltage from many of the ODB11 apps / bluetooth adapter combos. ie: carista, dr prius, hybrid assistant, torque, etc. In previous Gen Pri there was a 12 volt battery check available on the MID screen after putting the Prius into maintenance mode. Those previous Gen Pri maintenance mode checks are not available in maintenance mode on the Gen 4 Prius Prime.
If you use Hybrid Assistant with a compatible OBD2 adapter, at startup, it shows the 12V battery voltage.
Deep discharging of lead acid batteries shortens their life. There are blue tooth monitoring devices that you can attach to the battery. I think it was @Mendel Leisk that mentioned them elsewhere.
Thanks everyone, I'm all new at this. So I guess there is no easy (from the Prime itself) way to know the status of the 12V battery without doing tests. My OEM battery is still "good" and if used at least weekly it'll be no problem. But leave it only 2.5 weeks and it won't start. Don't want to keep calling AAA anymore so bought a 1.75A charger ($16) and jump kit ($38) that just came. Haven't tried the jump kit yet but the charger works fine. It also shows that after driving the car for about 30mins yesterday it was 11.9V today, so not too bad. But again, leave it for 2-3 weeks and it won't start. So I figured if I know I'm going to use the next day it I can use the trickle charger (or just use it anyway), and if I suddenly have to use the Prime and the battery is dead I have the jump kit as well (then driving it will charge it). Prime's my car but have been using a relative's car recently as I take them everywhere and drive them, so there are times when the Prime doesn't get used for a while. But I still love my Prime! Anyway, thanks for the help. PS: tried to post the Amazon links but PriusChat system not allowing it now. I bought the "Nexpow Car Jump Started, 1500A Peak Car Battery Jump Starter Pack Q10" (was $38.XX when I bought it a few days ago, price is a bit higher now) for the jump kit... And the "Nexpeak 1.75 Amp Car Battery Charger", was $16.XX when I bought it a couple days ago on sale, it's still about the same price.
I use one of these: Battery Monitor BM2 BM3 Bluetooth 4.0 Wireless Battery Tester 12V Automotive Battery Load Tester,Automotive Charging and Cranking System Monitor Digital Battery Analyzer for Android & iOS
Here's an older thread *( started by @Rob43 ) that might help to get you up to speed on the Primes 12 volt battery 12v Battery Is Discharging, Re-Charge Now ! | PriusChat
