JRP3
Hyperactive Member
Highly unlikely. Thinking about it more this may simply be an improvement to eventually allow the million mile warranty.
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Highly unlikely. Thinking about it more this may simply be an improvement to eventually allow the million mile warranty.
ℬête Noire
Active Member
Yeah, you'd hope that the filter would be only for "just in case", for protection from an "surprise" wear snowballing. They may have moved to a more active circulation for heat dissipation reasons?
The electric motors are somewhat different tech, right? Would that have any influence on how the motor/gearbox combo is designed?
Wet cells have significantly more energy capacity than AGM. If they switched, then presumably they did quite a profiling exercise to figure out what works best for their loads and recharging profiles.
Interesting point. The 3 is supposed to be Tesla's first permanent magnet car. That means it's phase locked - the inverter phasing always matches the motor speed, with the slip angle between them determining the torque.
I hadn't been thinking about it, but I think that's exactly why it has the recirculation motor - and likely the filter to protect that pump. In other EV manuals and forums there are explicit warnings about not using the motor to hold the car on a slope - because on a permanent magnet motor it means running power continuously through the same couple of poles, leading to differential heating of the rotor. (Doesn't apply to the induction motors Tesla has used to date, where the fields are rotating relative to the rotor at all times.)
Unlike those companies, Tesla decided they could program the motor to be a heat source for the battery while the car is stationary. They probably need that oil circulation to keep the motor temperatures even throughout the rotor and stator when they are heating with it or doing high torque zero or low RPM operations.
AGM batteries often have a vent as well so the vent tubing doesn't definitely tell us it's a wet cell. Looking at the AtlaxBX website I can't tell for sure (after looking at the video and website again, it's not so clear after all)
arnold
If I remember correctly Tesla added a gear block flush to the 1st year maintenance for the S&X probably because they saw some contamination that could cause problems if left in there. By adding this filter maybe they can remove that item from the maintenance schedule to make the cost of ownership cheaper, while still maintain a long lifespan. I think it is a good thing.
JRP3
Hyperactive Member
I installed Bosch AGM battery, Bosch Platinum Series AGM Battery Group, Size 24F | 838890 | Pep Boys, in my 2012 RAV4-EV, it has a vent tube:
I also had replaced the 12V battery in a 2002 Prius with Optima Yellow Top AGM, D51R | OPTIMA Batteries which also has vent tube.
arnold
I would guess the filter assembly, electrical pump, tubing and associated wiring would cost more than using a better quality steel in the few gears associated with a one speed differential.
JRP3
Hyperactive Member
Interesting, thanks. I've heard that Optima quality has gone down, if you want a top quality sealed AGM I'd go with Odyssey.
highly doubtful given their focus on longer term reliability.
The filter just maintains the oil in better condition for longer - more likely to head for the claimed million miles target.
Remember that the semi uses these motors as well.
insaneoctane
Well-Known Member
I can't believe Tesla chose to save money on the resistive battery heaters by adding the oil circulation system we are seeing here. Feels to me like the MS/MX have historically gone through transaxles. We also know Elon has been talking about 1M mile drivetrains for a while. The fluid pump and filter likely make the transaxle much more durable and gave Tesla the option to forego battery heaters.
Tesla is all about synergistic solutions. I'm sure they didn't set out to replace the battery heater with the fluid pump.
More likely, they wanted the permanent magnet motor for efficiency reasons, and looked at durability and decided they needed the filter and pump to keep the heating even - and then decided that if they made them big enough, they could do away with the pack heater.
The original big motor drive units haven't had the best service history (though apparently a lot of the replacements were for noises rather than outright failure, and Tesla eventually discovered the noises were actually external to the DU itself.)
I haven't really read of replacements of the second generation units (in the dual motor non-Performance cars and the front of Performance cars.)
I'd prefer to see the cabin filter on the intake side of the blower to prevent dust and dirt from building up on the centrifugal blower. As dust accumulates, noise will increase and performance will deteriorate.
Agreed. Love my Massive Bioweapon HEPA filter, tilted to shed debris and located at the front of the system, big enough for minimal pressure losses and flow velocities. (Love the activated carbon ones even more, never have to smell any of that crap.)
I'm not quite clear on how that end works - maybe Ingineer can weigh in. In his video, we see a cylindrical opening leading down into the dash, but I'm not sure how it interfaces with the Frunk cover - or maybe it doesn't, and just sucks air from underneath?
Anything small enough to fit in that intake duct will likely create too much restriction. You could put a pretty fine mesh screen there to keep the big chunks out.
Better than nothing and likely what I'll do.
It looks like there's a ridge just inside the opening. I'll have to measure it once I get my 3 but I'm thinking a 3d printed insert that contains a mesh screen might work well.
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