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Seller backed out
- Thread starter thefortunes
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There are two mods. They replace the separate PEM and motor fans units with a single motor dual fan unit that is more reliable and less susceptible to contamination. Then they add a large metal shroud around the area, which only allows air in at the top. This helps prevent stuff from the road from being ingested by the fan.
wiztecy
Active Member
Find a used MC240 or a Foundry charger for mobile use. They're tanks and I haven't heard of any failures on those... Telsa Technicians backed up also that they're better. Yes, I've been reading about many UMCs fizzing out.
Yeah, I was wondering how smart I was to get the HPC, given that I ended buying a UMC also and charge at 40A anyway. But now I'm very happy I did so. The UMC gets a lot less wear and tear this way, so it'll be working when I need it on the road.
wiztecy
Active Member
Doug, is your HPC dialed down from 70AMPS? That in itself is huge benefit... less wait time to drive off from a charge. I picked up an HPC a few months ago, would like to install it but it appears I'll need to upgrade my service to support the full 70 AMPs of current.... otherwise I'll have to dial it down. I believe one needs to run a 90AMP breaker as well for the HPC.
I have been using a HPC successfully on a 40 amp circuit for 4 years. I have the amps dialed down to 32 on my Roadster.
No, my HPC is fully capable of 70A. I actually did upgrade my service to support it. Wasn't cheap. But I have have my Roadster dialed back to 40A. I've charged the Roadster at 70A just once in the last year.
I've also swapped out the cables, so my HPC is now J1772. That allows me to do a faster charge on the Model S if I need to. I've actually used it to charge the Model S at 70A twice now.
wiztecy
Active Member
Is there a reason you're dialing the Roadster back to 40AMPs and only charged it once at 70? Was under the impression that pack should handle it fine due to its size. I know 70AMPs isn't as efficient and believe 30AMPs is the most efficient if I recall from the earlier research. Cool on the J1772 retrofit and flexibility.
I have to get in touch with my neighbors son... he came over the 1st week I had the Roadster to compliment me on it and offered to get the service wired up for me at cost. He's a certified electrician... also he gave me his card, he works for a solar company and said he'll help me install solar as well at cost. That's very tempting for sure...
I have to get in touch with my neighbors son... he came over the 1st week I had the Roadster to compliment me on it and offered to get the service wired up for me at cost. He's a certified electrician... also he gave me his card, he works for a solar company and said he'll help me install solar as well at cost. That's very tempting for sure...
Yes 70A is less efficient. It also makes my garage hot! We have insulated garages up here. Great in winter but in summer with a Roadster charging at full power, it gets hot. The Roadster ends up running the HVAC a lot. 40A is plenty fast enough for overnight.
Funny thing, because I had the only HPC in town, Tesla always charged their demo Roadster at my place when they did an event here. I think they may have used full power more often than me.
Funny thing, because I had the only HPC in town, Tesla always charged their demo Roadster at my place when they did an event here. I think they may have used full power more often than me.
dhrivnak
Active Member
Tom Saxton did a nice study on charging and determined 40 amps was most efficient. While differences were not large charging at 70 amps causes the AC to run more wasting energy and heating up the garage. 70 is also harder on the power companies. Since 40 amps always gives me a full charge by morning why mot charge at that rate.
If I was evaluating the value of the 37 month warranty on the CPO I would not only compare the likelihood of repairs costing more than the cost of the warranty but would include the value of the additional marketability of the vehicle if I needed to sell it (I said need because I can't imagine ever selling my Roadster voluntarily 
). Many people aren't comfortable buying a vehicle like this without a manufacturer's warranty attached. For me there is also value in the piece of mind knowing that if anything goes wrong I don't have to think about it; Tesla will just take care of it. Because of the high cost of the PEM and Battery I feel like the value of the warranty on the Roadster is higher than an ICE. I can afford to pay for the repairs if needed but if I was deciding between a CPO with a warranty or a private sale with current CPO prices where they are, I would go with the CPO if they had one that matched my preferences (color, etc.).
Good luck. I am sure you will love owning a Roadster!
). Many people aren't comfortable buying a vehicle like this without a manufacturer's warranty attached. For me there is also value in the piece of mind knowing that if anything goes wrong I don't have to think about it; Tesla will just take care of it. Because of the high cost of the PEM and Battery I feel like the value of the warranty on the Roadster is higher than an ICE. I can afford to pay for the repairs if needed but if I was deciding between a CPO with a warranty or a private sale with current CPO prices where they are, I would go with the CPO if they had one that matched my preferences (color, etc.). Good luck. I am sure you will love owning a Roadster!
Not how I read it.
Tom's study in cool weather
Tesla Roadster Charging Rates and Efficiency - Tom Saxton's Blog
showed that
My study in high temperatures
Charging in High Temperature environments 13A vs 32A vs 70A: cost of air conditioning
showed that
My conclusion is you may as well go for 32A or 40A as the efficiency benefit above that is zero or marginal. You only need 70A if you really need to charge the car faster.
P.S. One advantage of 70A is a reduction in noise pollution - those incredibly noisy fans only run for half the time compared to 40A
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