Battery Vent Tube Questions

Does anyone still paying attention to this thread know what the current draw of a Gen 2 prius sitting in your driveway with IG-ON --two clicks of power without pressing brake, not READY mode-- is? Assuming headlights off, sound system off, climate fan off, dome lights off.

I'm asking because I have twice now brutalized my new smaller 35AH AGM replacement battery, since replacing the tired regular 45AH OEM battery. I am surprised at how quickly the car dies. When working on it 'for a couple of hours', leaving the front door ajar, I brought the voltage (measured at the cigarette lighter) down to 8 before immediately correcting the situation and charging it with a decent 4AH x 8 hour charge. The second time, I must have left the car in IG-ON and walked away. I came back many hours later and it was entirely dead, no voltage registered at the cigarette lighter. It's on the charger now and I'm resolving not to do this any longer!

 

Considering that Prii charge rather slowly during driving, with the Gen2 being even slower than the Gen3, there seems to be a persistent issue of a big portion of the Prius fleet being perpetually undercharged, especially for drivers with short or no commutes. Pandemic shutdowns made it worse. You may have started the work with little charge on the 12V battery.

So any time you might be leaving the door ajar 'while working on it for a couple hours', consider putting it on a slow charger or a battery maintainer for the duration of the work. Or if not safe during the work, do it ahead of time, or disconnect the battery and charge it separately while you work. Or even do it regardless of the door position.

 

Yes, that's a probable scenario. I was also thinking about placing a small (10w?) solar panel on the dash, but I'd need to be able to get to 12v hot all the time, and these cars only have 12 when on Acc mode or IG-ON. If I knew the current draw on IG-ON I could plan better. Yes, I know that I could hook my tester up between the battery and ground, let it sit 30 min and take a current reading... As an additional factoid, I've ordered a handy-dandy battery load tester/analyzer because we all should have one of those, right?

 

sitting in your driveway with IG-ON --two clicks of power without pressing brake, not READY mode-

in this condition, the inverter cooling water pump is running, with no "recharge" being supplied to the 12v battery. Say good-bye to your 12v battery relatively quickly.

 

Yes, this is what I'm interested in. As a tangent, I bought a new OEM inverter pump, which will soon be installed, A non-auto website post mentions that the pump looks to be a 50W device (I think that's about 4.2 12v amps by itself) and would explain why even a larger aux battery like the OEM one (mine is undersized at 35AH,) would be dead quickly...