Battery coolant lifetime?

[lzolman]

I attended an EV show today at the Lawrence, MA municipal airport. Loved that it was a relatively small affair, maybe 20 cars in a nice mix, and I could relax this time because there were no rides being offered.

Spent a few minutes chatting with a fellow who runs a shop that works only on EVs, doing things like battery upgrades on Leafs, lots of varied services. We discussed the maintenance requirements of a Tesla, and he was very certain that the battery coolant has a useful lifetime on the order of 120,000 miles and then needs to be replaced because certain additives begin to break down at that mileage.

I showed him the refresh MS LR manual (which I happen to keep, printed out, in Nameless) where it says the coolant system would never require maintenance under normal circumstances. He just shook his head and couldn't accept it.

With a potential lifetime of a battery (and, presumably, car) in the multiple 100K's of miles, it can't be both ways...

Thoughts?

 

[Wol747]

My own thoughts - based on nothing but gut instinct - is that Tesla have an interest in promoting zero maintenance as an EV feature. Sure, there are no oils etc to change, but I would have thought that greasing and lubing steering etc would be required at least?

 

[PCMc]

You are correct that the current manual states that "should not need to be replaced for the life of your vehicle under most circumstances." It actually goes on to state that any damage from opening up the battery cooling reservoir is not covered under warranty. What I have not found documented anywhere is what are the circumstances where coolant replacement would be recommended.

Early on there was a recommendation that the battery coolant was to be replaced every four years of 50,000 miles. That went away when Tesla did an major overhaul to the maintenance schedules somewhere around 2018. I presume by that time they had seen enough cars get to the 4 year / 50k miles threshold to have sufficient data, along with continual improvements in HOAT coolant chemistries in that era, that gave them the data to move away from a scheduled repair interval. This is where if that's out past 10-12 years that Tesla may consider this to be sufficiently long enough that is not warranted to even publish the recommendation.

I'd actually think time is a better indicator than miles when it comes to potential depletion of the coolant additive pack. Maybe when cars actually get to the 10-12 year plus range in a few years, and have not needed the cooling system opened up for other repairs, we might see Tesla recommending to owners to do this service on a case-by-case basis when vehicles are in for other reasons.

 

[rickyjb]

whats the chances that a component in the cooling system might need replacing the first 120k miles ? its no longer recommended every 4 years or 50k , but if something fails and the coolant has to be drained surely they would put new coolant in right.

 

[bruce4000]

I’m an ice car, the coolant is subjected to high temperature swings unlike in an ev so I would expect coolant would last longer.

 

[lzolman]

whats the chances that a component in the cooling system might need replacing the first 120k miles ? its no longer recommended every 4 years or 50k , but if something fails and the coolant has to be drained surely they would put new coolant in right.

Very good point, that there's a "point of diminishing returns" for having it as a scheduled maintenance item. It's not really saying it'll never fail, but rather that the risk/reward of not changing it is good enough. Works for me.