2017 - 2022 Prius Prime - 8.79 kWh Battery and charging system info

@RandyPete, you're new here so no harm no foul. But if you'd been here regularly for a year, you'd have surely seen that exact video posted at least 50 other times. It's a very popular video and some of us have seen it's full length a few time already, much less the times it been posted at a specific timestamp.

 

There is a report button at the bottom of each post that will inform the forum moderator(s) of a members request concerning that post above the report button.
After a post has had a response I believe it's much harder for the mods to remove. I wouldn't worry about it. Like I said this video has been posted so many times, one more time is a drop in the bucket, so to speak.
I responded just as a service to you, since I think it's nice to have an understanding why the thread was not getting any responses.
Besides it's a great video and many if us are hoping the Professor Kelly will have to opportunity to follow up his work displaying the Gen 4 drive train with similar videos for the Gen 5 Prius Prime.

 

I think it’s fine to bring it up again with the link. Threads get buried, and users who have seen the video might not want to see it again, but maybe some do, and people who never heard of the video now see it.
I haven’t seen the traction battery charger charging the 12 volt.

 

One minor note - it never really uses 12V battery power for the heat - it will only use 12V power being produced by the battery charger.

The Gen 5 differs in a few ways, but is mostly the same. Three 24-module battery stacks, with each module having about double the capacity, and the battery assembly is under the car on the outside. Heating system is the same, but the cooling is now using A/C refrigerant piping, rather than airflow.

 

Yes he is.
I also have a question if @KMO or @tovli can grab the voltages from DrPrius at 100% SOC and at 0% SOC
My calculated guess is about 280 volts at 100% SOC and around 252 volts at 0% SOC ( when the engine switches on ).

 

The Gen 4, and hence also the Gen 5, as that's not one of the differences.

 

I think @tovli already supplied these in a thread you were in.

Latest Dr Prius SOC vs Car SOC | PriusChat

292V fully charged (4.06V per module, 91%), 249V on switch to HV (3.46V per module, 14%). I assume those DrPrius SoC numbers are the direct OBD readouts, same as Techstream shows.

 

I appreciate your patience and the link, Each time I go back to that thread I understand a bit more, see things I missed during previous views and even if I'm still not straight / understanding all the similarities and differences between Gen 4 and 5 Primes yet, I'm at least more clear about the traction pack configuration ( ( 3 stacks ) of ( 24 cells to each stack ) at a ( nominal voltage of 3.7 volts per cell )) .
Full charge voltage of around ( 292 volts ) and fully discharged voltage of around ( 249 volts ) according to the cars SOC gauge.
And packs nominal rated voltage of just over ( 266 volts ).

I see and understand a lot more than I've listed above, although I do learn more and see things I've missed each time I go back.

 

What do you mean? The charger module has output for the 12V battery. They are powered when the traction battery is being charged.

The battery heaters use the 12V system, not the HV. You can see that the heaters are On when the charge port light is lit although the battery isn't charging.

 

Yes, the battery heaters use the 12V system, but the power is coming from the 12V DC output of the HV charger. It's not drawing power from the 12V battery.

 

When the traction battery is being charged externally from an ac circuit, the 12 volt battery isn’t being charged. I wish it was.
I have noticed something else about 12 volt battery internal charging. When the voltage drops below 13 volts in ready mode and when driving, the 12 v charging stops. It does drop below 13 and rise above 13 during driving for reasons unknown to me, and sometimes stays constant a very long time above 13, then drops.

 

The AC charger outputs a high enough "12V" voltage and current to power the heaters and other components and sustain the 12V battery, if not actually charge it.

While in READY mode, it is presumably trying to vary voltage with presumably some sort of "intelligence" to try to control charging flow. (I do recall seeing complaints that it's not aggressive enough).

 

I think I've read the 12V is being charged at the same time as the HV, but maybe I'm confusing its AC charger with the one in my Model 3 too...

 

When the power is drawn by the car's charge cord, the accessory grid of the car is being powered. The 12V is part of that, so it is getting a charge.

Now, the drain on the battery when the cord isn't energized could end up in a net drain between plugging and unplugging the car.

If concerned about the starter battery, it would be better to charge at Level 1. The 12V system is being powered from the plug for a longer period of parked time than Level 2.

 

So, is the 12V battery being charged when plugged in and charging or not? I've got conflicting answers.

In Canada, when it's cold, the heater turns on and off to keep the battery above freezing (or as close to it when it's very cold) and while plugged in, even when not charging, the 12V battery is kept topped of since the battery heater is fed by the 12V battery. Like I mentioned in a previous comment, you can tell when the heater is running by the green LED in the charge port being On.

 

Is the 12V being charged when the car is running?

The starter battery is wired in to the 12V accessory system. When that system is being powered by something besides the 12V battery(alternator, DC to DC convertor from traction battery, etc.), the voltage is above the full point of the 12V. For the 12V to not be charged at that time, it would need to be disconnected from the system.

So the 12V is being charged with the traction battery or when the battery heater is on. The car won't charge it just to keep it topped off. If not charging or running the heater, there is still a chance the 12V can be drained down while the car is plugged in.