Does Prius have engine thermostat and what if it is stuck?

i bought those glasses from the comic boks back in the 60's, they didn't work.

 

<GROAN>
Source: Prius - UPS Project

• 75 A - maximum 2003 Prius current before voltage drops
• ~1035 W - maximum practical power draw on 12V circuit to external load
• ~450 W - Prius internal, 12V overhead
• ~745 W/hp
• ~2 hp maximum 12V load (1035 + 450) / 745
• similar limits measured with 2010 Prius

Note: 1 kW dropped into a 12V battery leads to a lot of heat . . . steaming electrolyte if any remains.

Note 2: 2010 12V battery hold-down has a temperature sensor.

Bob Wilson

 

i'll wait for chappy's reply.

 

It has a regular thermostat, shown in the Repair Manual. I can't quite ascertain where, without actually digging down to it. Removal instruction says to take off the air cleaner assembly, and the dipstick guide sub-assembly, to access.

 

I am an EE !! but no training in automotive stuff ... That is why I am so skeptical about this claim !! IF the 12V battery would consume more then the quoted 70W ( I was comparing it to the headlights which I KNOW is nominal 110W !!) constantly rather then until it is charged it would be almost unmeasurable by mpg loss except during quite low speeds where the mpg is shitty anyways ...

So when my battery will be dying I will try to measure the current .... the only thing would be visible is that the car charging circuit will stay elevated around 14.2 instead 13.6 .... HOWEVER it is in that range with almost ANY load like the headlights on !!!

exactly !!! so where those lost mpg-s goes SURELY not into the charging of the 12V battery ...

also WHEN the car is in READY all 12V (13.6V) power is supplied by the DC/DC converter and NOT the battery and from this measurement the overhead is is almost a magnitude higher then base charging ..... is it possible that other systems somehow affected (somehow??) yes "everything" is possible (like chemtrail) but again they ALL powered by the HV (through the converter) not sure how they would even notice the difference. Thought experiment:

1. start prius put into ready mode and disconnect 12V battery ... that would mean totally dead 12V battery right? So what would happen ... my bet is NOTHING... (nothing negative to the fuel consumption).

I have to say I will not do this for real.

 

i can't stop recommending 12 volt health test when people complain of reduced mpg's, i've got nothing else.

 

Well, but that's the opposite of the test that would be interesting. The aux-battery-mileage-hit hypothesis, as I understand it, is that a faulty aux battery, maybe with a shorted cell or two, is sucking down more charge current at 14 volts than a healthy battery would. (An upper bound on how much more is what we could get using a clamp meter if somebody thinks they have that problem.)

A disconnected aux battery draws less than the normal current.

Bob has already supplied sort of the ultimate upper bound ... if you see no sign of your battery boiling, you're probably not losing more than one horsepower into it ... but I suspect even that's a generous estimate compared to the maximum loss into such a damaged battery in real life. (Also, a battery with a shorted cell or two would have telltale open-circuit voltage 2 volts or 4 volts low!)

Your car doesn't mind at all having the aux battery unplugged after being made ready. Unlike Grandpa's car, where the alternator really needs the battery to be there to buffer voltage swings, the Prius regulated DC/DC converter stays happily regulated without a hitch. That's my usual approach if someone asks for a jump from my car. I don't want my DC/DC converter exposed to their possible starting currents, which would probably blow the 100 amp fuse. So before I connect any jumper cables to my battery, I just unplug the connectors on the positive terminal so it's isolated from my car. In essence I'm using just my battery alone as the jump source. But I don't want to risk draining my battery too far and being unable to start my own car, so I just start it first before unplugging the battery. Then after unhooking the jumper cables I just plug it back in, and the already-READY car recharges it.

-Chap

 

I finally got around to putting my jump pack in the hatch tray, just leave it in there 24-7. Helped my daughter start her Pilot one time so far. Much simpler than having to maneuver vehicle into position too.

 

I was already convinced that the mpg loss is NOT Wasted on the battery. If there is a

The disconnect would simulate (I thought) a battery which needs constant charging I was guessing that something senses that the battery is full do not how... I know that my car in normal condition (it was driven day before) lowers the charging voltage from 14.2 to 13.6 about 30-40 minutes (of course no A/C no headlights) and after a weekend NOT driving the car it would take like an hour to hour 15 min ...for the same thing to happen. Not sure what the system looks for or senses. I confirmed my battery SOC a few times to actually measure open circuit voltage in the morning and it was consistently lower after two days not driving (even after 24 hours) then when I drove the day before. My commute to home is about 1.5 hour in a good day ... so that is sufficient to have the 12V fully charged. Sometime people do not realize that driving only 10-20 minutes only a day they actually deplete the battery ...

just got myself a clamp type DC meter so I WILL take measurments soon ... my battery almost 3years old ... and will measure it for a while both open circuit voltage charging current and ambient temp .... starting next week so we can put to rest OR prove this theory..

 

I'm betting you'll find less than 2A charging current (probably less than 1A) if the battery is in good shape and near fully charged. A lot more only if it's badly discharged or has a shorted cell (the only time an AGM battery will produce remotely significant quantities of hydrogen, unless the charging voltage is abnormally high).

 

Roll of toilet paper...always part of a good emergency kit. You should also throw in a pair of clean underwear.

 

What is that orange thing?

 

Collapsible traffic cone.

 

Ah! good idea.

 

thought it was a clown suit.