Is the starting 12v battery lithium or flooded and how to store

1. The 12V battery does not start the car. The car is started with the HV battery and one of the MG units. The 12V battery only powers the car's electronics, lighting, etc. That's why it's so small.
2. The 12V battery is a traditional flooded lead acid.
3. The 12V battery will not be maintained* if the car is left plugged in. In fact, the manual expressly advises the owner not to do this.
4. Your best bet for preserving the 12V battery while you are gone is to either disconnect it or install a battery maintainer(such as a NOCO Genius 1, 2, or 2D). Which route you choose will be best decided by the conditions where you plan to store your car.
5. I believe the 12V plug is switched(so it's not live when the car is off), but I would reconsider your choice to use it to power your cooler. As said before, the 12V battery is pretty small because it doesn't start the car. That means you have far less power storage available to run a 12V accessory. You'd be better off running off the 120V with an inverter or just switching to a 120V cooler.

Can't help you with the rest.



*The car does actually monitor and charge the 12V battery, but only if it's also actively charging the HV battery. So if there's no appreciable draw on the HV battery, the 12V battery will slowly deplete and the car won't do a thing about it.

A scenario that may eventually apply to you is in freezing temps. If the car is plugged in, it will try to maintain the HV battery at a temp where it can provide full power immediately at startup. To accomplish this, it uses a resistive heating element at the bottom of the HV battery that is powered by the HV battery. So if the car runs the heater long enough, it will deplete the HV battery enough to initiate a charging cycle. During that cycle, the car will resume monitoring the 12V battery and charge it if necessary. A normal USA Prius Prime will do this for up to three days before shutting off that system. Prius Primes delivered to Canada and Alaska will go for up to 30 days before the system is disabled. But this doesn't apply to you in this instance since you will be gone during the summer and the temps won't drop low enough to ever trigger the heater, plus you'll be gone for far longer than 30 days.

 

That's what I've been hearing. And it's back in the hatch? is there a vent on it? With Gen 2 and 3, they were AGM and vented. Supposedly because they're in the cabin. But with gen 5 it's flooded and in the cabin. How'd that come to be, maybe regulations changed??

 

Just wanted to note that this is just another ECU setting that you or the dealer can mess with in Techstream. So it's just something that's set up as part of the pre-delivery inspection, rather than being an actual vehicle difference.

 

Yeah, I think that should work, actually. You can set charging schedules in the car, and you could tell it to do a short period every Sunday.

You're the first person who's made that suggestion, and I can't see anything wrong with it - it should keep it topped up for quite a long time, if you're taking the care to start with a low charge. (Toyota themselves suggest long-term storage at "---" - bottom of EV range, top of HV buffer, so I wouldn't start from 60%).

Note that until recently many including me thought the G5 was like the G4 and had a separate 12V DC converter used when charging, which only output a maintenance 12V level, which would have made that less effective. But it's recently been established that it does now use the main one, and that it will apply full 12V charging voltage as required. (See the video above, and this thread about it)

Only note of caution is that there is a TSB about current drain while plugged in - if your car had that fault unfixed it might not last the week between top-ups. Otherwise, it should be fine for a week.

 

When you are camping you can put the car into “Ready” mode and the 12 volts will be maintained by the Traction battery. “Ready” is also required to power the 120 volt sockets. Once the EV range is used up, the gas engine will start periodically to keep everything powered up. No need to worry about the 12 volt battery while the car is in “Ready” mode.

The 12 volt socket also has power when the car is plugged in to charge and has been put into “Room” mode whereas the 120 volt will not be available in this mode, therefore a 12 volt cooler is actually better for situations where you are camping with the car charging.

I would think that the traction battery will power a Cooler for a long time provided you ensure that the car heat and ventilation system is shut down and there aren’t any other power draws - headlights and parking lights off if your car allows that.

You can use HV mode to hold the traction battery charge while driving to the campsite or use the Charge function to bring it up to about 80% while driving.

 

What is the power of your water pump? Multiplying its power by 14 hours will give you the calculated value of useful energy expended. The Prius battery should expend more energy since there is also unproductive energy expenditure for conversion and transmission through the cable.