Hello everyone, I’m from southern China and moved to Canada last year. I bought a 2023 Prius Limited AWD, and since I had never driven a car or seen snow before, everything feels both exciting and challenging for me. The biggest problem I face is that when the temperature drops below -15°C in winter, if I don’t drive for a week, my battery completely drains and I can’t start the car. I have to call for roadside assistance to jump-start it. As a work-from-home new driver who’s still a bit afraid of driving, it’s common for me not to leave home for over a week, or even a month, during winter. Last winter, I called for roadside assistance four or five times, and it was really frustrating. This year, I’ve decided to figure out how to keep my 12V battery charged enough to start the car. I’ve made some efforts and encountered some questions, so I’d like to ask for advice from experienced Prius users here. I bought a NOCO GENIUS1 charger and disconnected all the cables from the 12V battery in the trunk, including the thin vent tube. I directly connected the NOCO clamps to the positive and negative terminals of the battery and used the “default” mode to charge it for over ten hours. However, the charger’s red light kept slowly pulsing (according to NOCO’s instructions, the light should turn green when fully charged). After reconnecting the cables, the car went from completely dead to being able to start, but why didn’t the charger ever turn green? Also, do I really need to disconnect all the cables to charge it? Can I just clip the clamps onto some nuts or metal tabs connected to the terminals? And am I using the correct mode by charging in default mode? Or should I switch to AGM mode or LITHIUM mode? I found a cable in the trunk under the mat that seems to be included with the car. Its label suggests it has a “trickle charging” function, which seems to suit my needs perfectly. However, I couldn’t find any related instructions in the 500+ page manual. Does anyone have any idea about this?
1. The Noco Genius 1 is designed to charge 12V batteries up to 30Ah. Isn't the new Prius 45Ah? If so, that's probably why it never charged more than 75%. 2. Ohh.. that was one is part of the "Comfort+" accessories that Toyota Canada offers. Here's the owner's manual for the battery trickle charger. https://s3.amazonaws.com/toyota.site.toyota-v5/tci-prod/toyota/media/pdf/toyota-comfort-plus-trickle-charger-user-manual-03OCT2019-en.pdf?ck=11222024045529 Looks like you plug that cable into the outlet installed in the front bumper and the other end to a power outlet in your garage or at home.
It was common to do things like this to cars arriving in Alaska and needing real winterization, at least as far back as the mid 1970s. You'd mount an extension cord reel/bracket on the front grill or bumper, and that would feed a block heater and an interior cabin heater. Also a small nightlight mounted on the front of the car- that way you could tell at a glance, usually from inside the warm house, if your car was getting power. Sometimes you'd add a battery warmer blanket or a trickle charger. Each model of car needed slightly different tweaks.
After consulting with my dealer, I’ve confirmed that I don’t have a trickle charger. The cable I found is only connected to the Block Heater system, which was a mandatory add-on when purchasing a car in my area. So now I have two options: Go to Toyota and install an official trickle charger, but I’ll need to wait at least two days or more to get a quote. Buy a new third-party charger. Based on what you’ve told me, my current NOCO only supports 30Ah, but I need 45Ah? I’m not sure where to find out if my car battery is 45Ah. How can I confirm this information to ensure I purchase the correct third-party charger?
Look at the labels on the top of the toy battery. AH rating is usually included on that label. Take a cell phone pic of that info for future ref.
This is the problem right here... A 1 amp charger or a trickle charger only works if the 12v system is designed properly and Toyota has failed to do this in every Prius iteration. Much like the trickle charger they aren't sending enough amps to the 12v because in their tiny little heads that battery is not drained down very much at all when starting the car. But once you have an event that drains the battery down significantly, the charge amps the car sends, or that a 1 amp or lower trickle charger sends will take near forever to fully charge the 12v back up again. Just buy a cheap smart charger of 10amps or more and once or twice a year give the 12v a full charge.
The NOCO Genius1 will work with your 12v battery. It will just take a very long time to fully charge a battery that has a low state of charge. It may take 24 to 48 hours of constant charging to fully charge your 12v battery. You would be better off to use a NOCO Genius2 OR NOCO Genius5 charger.
Here's an idea, how about buying a legit smart charger with 20amps of power rather than a brain dead so called "genius" charger that are designed for non hybrid cars that have legit alternators that pump legit amps into the 12v unlike what Prius does: 20A Smart Car Battery Charger Maintainer 12V 24V LiFePO4 AGM Trickle Charger USA | eBay
noco genius is a great maintainer for a good price. your best bet is to replace the 12v, and keep the noco on it when not driving
No. Well, Owner's Manual likely says you do, but... Our '10 is on a charger (CTEK Multi US 4.3, with quick-connect wire harness), virtually all the time, everything connected. It would be totally impractical in our low usage scenario to do otherwise. With Noco, I think the 2 amp Genius 2 (or 2D, the onboard one) is more suitable. Consider block heater too.
