It's a booster pump - that flow rate includes a second main pump in the loop, I would expect.

What's wrong with an electric pump from a factory EV? At least you know it's automotive qualified...

Pumps are gravity (head pressure) fed from the reservoir to prevent cavitation. If you pull after the radiator, it's not just the pump that sucks.

Congrats on the newly acquired poop factory, btw 😛

 

Haha, thank you.

I can't imagine them giving a flow spec for something with the assumption that it's being added to the flow rate of another unknown pump?

In any case, there are other options in that price/size range, but not all of them publish the exact specs (eg Bosch has a handful of OEM 'auxiliary' pumps). I'd have no issues going with one from an EV, it's just hard to find actual specs on those too.

Someone linked this in another thread, it's a bit more flow but possibly not too much: Water to Air Pump 0392022002

As for the flow, I was assuming I'd be mounting the pump(s) near the bottom of the (down flow) rad, then pumping through everything and back to the top. Wasn't really thinking about a reservoir, just an expansion tank. Should I be using a pressurized reservoir, then?

 

I can't imagine them giving a flow spec for something with the assumption that it's being added to the flow rate of another unknown pump?

Correct - the flow will be for that pump at the specified pressure rise. "Booster" pump just means that it is a low-pressure but high-flowrate pump usually used to feed the suction of a higher-pressure pump (so the pumps are in series - same flow, each contributing a part of the pressure rise); if all you need is that low pressure, then you don't need the other pump.

 

No. You cannot pressurize.

Reservoir, surge tank, expansion tank -- all the same device that serves several functions. You don't want the pump pulling through any flow resistance.

Pumps are variable speed based on temperature sensing - your job is to hold a temperature range, not firehose the F out of the parts being cooled/warmed.

 

Hm, maybe that wasn't the best way to phrase it. I was thinking a chamber with a cap on it at the inlet to the rad. I guess the expansion tank currently connected to the rad wouldn't ever do anything since system pressure would never even get close to whatever the cap is rated to hold. May as well ditch it, make sure the aforementioned reservoir is the highest point, then add some kind of breather? That way I know I'll never have some kind of spike in gauge pressure of the system, else I'd fully expect the batteries to act as a relief valve, haha.

 

Hi all,

I may be overthinking all of this, so I thought I should solicit some input to see what other people think/are doing for their systems. I've also been away for a while taking care of my newborn son, so natrually this project was put on temporary hold. Glad to say I am getting back to it now and still hoping to be done the conversion by spring!

Anyway, I'm using a Leaf motor/inverter in the back of the car and most of a gen 2 Volt pack up front. The leaf inverter housing calls for 13.5 LPM of flow, and I'm not sure about the batteries. I'm also planning on dialing up the power beyond the stock 80kW so more cooling is probably a good thing.

What I'm trying to decide now is how to plumb everything and how much flow to try and ram through the system. I could put the batteries in series with the motor/inverter (batteries first!) or I could use two pumps that tee(or Y) off right after the radiator and go back together at the rad inlet. Or, I suppose I could use a single, larger pump and then tee off to motor/batteries in parallel, but then I need to figure out a reliable way to balance the flow.

The leading contender for a single pump in a series setup is this: ELECTRIC BOOSTER PUMP (EBP23) (12V) SHORT - PART No: 9051 It advertises a flow rate of about 17 LPM with a 1.5 psi pressure drop. Not sure how much of a pressure drop I would see in my system, but between the batteries, motor, inverter and piping from front to back, 1.5 psi sounds reasonable?

What do you all think?

Went with a Tesla coolant pump (I believe Bosch is the manufacturer for those) and used an adjustable y-splitter to control flow to the batteries and inverter as needed. They reconnect at the radiator. Remember to mount your pump at the physical lowest point of the coolant loop to prevent any air from getting trapped in the pump.

 

Cool, thanks. Good to hear a real example. How did you set the flow distribution? Check temps and adjust as needed?