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Discussion Starter · #1 · (Edited)
Antifreeze in my 2014 ED?::thanks_smile:

The coolant in my electric car I understand is to cool the battery only? I understand that I don't have to change the antifreeze very often, if at all and that the water antifreeze mixture last's a really long time these days, especially in a electric car that doesn't get hot.

Saying that I am wondering does the water get moving around when I'm charging the battery because you know batteries get hot when you charge them in my little home charger C&D batteries they get pretty hot sometimes. I understand that heat is the worst thing for a battery. so if you know the answer to that question let me know.


Authorized electric drive smart center :laugh:
Authorized electric drive smart technician. :crying:

smart enough to fix my ED? 1poke
 

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Some people believe in lifetime fluids - I don't. However, I might be very close to believing it for the coolant in the EV's. The coolant is really under no stress or extreme conditions like it is on an ICE. The coolant only circulates around the battery to keep its temperature reasonable. In fact there is no mention in the service sheets for ever changing the coolant in the EV's, but it is a maintenance item for the ICE's. Personally I don't plan to mess with mine for a long, long time. Not sure if it's still the case, but for awhile Mercedes was putting 15 year/150,000 mile coolant in their ICE cars. To me that means that it should last 50 years or so in the EV's. :)

Len
2014 EV Coupe 17,500 miles
2014 EV Cabriolet 9,500 miles
 

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Yeah, if you open the front service flap, you will see coolant circulating whenever charging or driving the car. The coolant does not only circulate through the battery pack but through the motor, motor controller/inverter ("Power Electronics Control Unit" in MB's terminology) and charger. The heating of the coolant when charging is almost all coming from the charger. The charging current in the Smart (about 10 amps max for level 2 charging) is not enough to heat the cells any amount to speak of.

With regard to the battery pack, the most important function of the "coolant" is actually as a "warmant". There is a coolant heater - and the circulation to the radiator gets shut off, when charging or operating the car at temperatures below freezing - and all the time if the temperature falls below -20C. In fact, the car MUST be kept plugged in so the pack can be kept warmed in at temperatures below -20C (-4F) or the pack can be damaged.

But also, Smarts sent to hot climates have a coolant chiller that runs off the car's A/C for keeping the pack cool when the temperature goes above 40C (104F). I still don't know if this includes all Smart ED sent to the USA or not.

So, "coolant" is not a good way to describe what that reddish liquid does for the battery pack. It is better described as the working fluid for battery pack temperature management in various ambient temperatures - not any temperature the battery pack itself generates - which is pretty minimal. The real heat generators in the Smart are the motor, inverter/controller and charger - and that is still minuscule compared to the heat an IC engine generates.
 

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coolant chiller that runs off the car's A/C for keeping the pack cool when the temperature goes above 40C (104F). I still don't know if this includes all Smart ED sent to the USA or not.
Good info Yinzer. I've got to think that all Smarts sold in the US, maybe in the world have the chiller and warmer included, but it would be nice to have someone verify that. Seems like a Smart could be sold in Minnesota where the warmer would be needed and then resold to someone in Phoenix where the chiller would be needed. I'm guessing Smart would have both bases covered?

Below is a shot of the "Engine cooling" page for my coupe from the EPC. Looks like it has the cooler and a pre-heater.

Len
2014 EV Coupe 17,500 miles
2014 EV Cabriolet 9,500 miles
 

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But also, Smarts sent to hot climates have a coolant chiller that runs off the car's A/C for keeping the pack cool when the temperature goes above 40C (104F). I still don't know if this includes all Smart ED sent to the USA or not.
Yinzer, good stuff! And to another previous query the diagram posted by sokoloff supports that the Bosch circulation pump is electric and NOT belt driven.

Absent any preponderance of climate related high temperature HV battery pack failures I believe that all 451 ED's sent to NA are carrying a "complete" heater/chiller package.

This was a major issue for the (air cooled) Nissan Leaf in the SW that ultimately led them to multiple HV warranty replacements AND the development of their "Lizard Battery."
 

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This was a major issue for the (air cooled) Nissan Leaf in the SW that ultimately led them to multiple HV warranty replacements AND the development of their "Lizard Battery."
Yeah. I understand that Nissan LEAFs didn't or still don't have any temperature regulation at all. One would think they at least need a battery heater - lithium batteries get pretty "sluggish" in cold weather - especially in the charging direction. They won't charge at all except at a trickle at around 10F or so.
 

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Len,

Where did you get that detailed part diagram?

Paul
Got it from the EPC - Electronic Parts Catalog. Mercedes charges $75 a year now for it I think, but I renewed my subscription for about five more years when it was free. If you need anything in particular, let me know.

Len
2014 EV Coupe 17,500 miles
2014 EV Cabriolet 9,500 miles
 

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Yeah. I understand that Nissan LEAFs didn't or still don't have any temperature regulation at all. One would think they at least need a battery heater - lithium batteries get pretty "sluggish" in cold weather - especially in the charging direction. They won't charge at all except at a trickle at around 10F or so.
The LEAF does have a battery heater that turns on at ~ -20°C (-4°F) and then turns off at -10°C (+14°F).

There is no cooling of the LEAF battery.
 
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