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Discussion Starter · #1 · (Edited)
I'm working on designing my cooling loop. The idea is to control flow via two solenoids to control flow to the original heater core when cold, and to the batteries to warm them on cold days, or bypass these for ordinary cooling. The "battery valve" in the diagram is a 2 way solenoid driven switch, sourcing coolant either from the coolant heater path or not, depending on whether the battery is below ideal temp. Here is a quick, dirty, terrible diagram. My question is am I off base, #1, and #2, what solutions are out there for the coolant heater I've indicated with a question mark below.

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Discussion Starter · #3 ·
After heating the passenger cabin and only if heating is on. Trying to reuse the original passenger heating setup but reuse a coolant heater for battery warming and passenger heat. Hmm, are you suggesting a separate reservoir and loop for heating vs cooling?
 

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No

I'm observing that the heat energy taken from your HV battery to run the coolant heater, in your diagram, has to go through the radiator when it's January in Chippewa Falls.

It's your loop design. I'm just providing the feedback you requested under #1.
 

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Discussion Starter · #8 · (Edited)
Damn, your right, clearly was thinking about the heating aspect when doing my thinking walk.

And that's the most common case here in Texas. Starting to understand why the OEM integrated coolant systems are so damned complicated.
 

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Discussion Starter · #13 ·
That is the plan. Was looking at these guys: these guys, which run about $60, or some Bosch ones I hope to pull from a junkyard if I'm lucky. I'm planning on running the loop with a VCU I'm writing for a small ESP32 or similar microcontroller (+ associated relays of course).
 

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I didn't say you needed proportional...you inferred you had it.

I merely stated you need to adjust the flow (is this why you used "flow" charts? 😂) between the two parallel paths or the lower flow impedance path may hog most of the coolant flow when you don't want it to.
 

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Discussion Starter · #17 ·
I didn't say you needed proportional...you inferred you had it.

I merely stated you need to adjust the flow (is this why you used "flow" charts? 😂) between the two parallel paths or the lower flow impedance path may hog most of the coolant flow when you don't want it to.
Yeah, that makes sense and had occurred to me with my limited knowledge of fluid engineering. This is a particular area I need to learn about. But it wasn't clear from your suggestion why I might need that addition. If I added a flow control valve there would I basically need a tunable valve that would be able to dial between three flow rates? Because in the current design there would be three cases: Flow only to the battery select valve, only to the heater subsystem, and partially between both.
 

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I have used the early, simple, two wire Prius coolant pumps in cooling systems. Prius also has a three-way motorized coolant control valve in the 04-09 Gen 2 models, that I have not used yet:
 

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Looks like that valve may have a motor in it. Any idea how it works, the connection modes, & the pinout?
No idea, at this point. In this video at~8:30, one is taken apart. It's motor driven through a gear train. It looks like it has a simple, electromagnetically activated positioning switch or sensor. Or, it could have Hall sensors. Although, that would probably take more wires?

 
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