TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker or making a Paypal contribution here: paypal.me/SupportTMC

THANKS and a few questions from new owner of 2008 Roadster 1.5 #243 Radiant Red

Discussion in 'Roadster: Technical' started by djf, Jul 29, 2015.

  1. djf

    djf Member

    Joined:
    Jul 15, 2015
    Messages:
    33
    Location:
    Santa Rosa, CA
    First: My sincerest thanks to all of you as I have spent countless fascinating and enjoyable hours reading the Roadster Forum posts which have been profoundly informative. Special thanks to the gracious and knowledgeable ecarfan for sharing the 2008 Owner's Manual pdf and several helpful tips, and to rock star Henry Sharp for the amazing Can JR which works perfectly with my Clipper Creek HCS-40 charging station and a number of free public chargers here in the California wine country. I will have a few questions for the collective wisdom of the group and will start with the most "urgent":

    The car was throughly checked out by the Tesla Service Center in Burlingame before purchase and they replaced the (single I believe) PEM fan which had a service alert and did a full service and gave the vehicle a very clean bill of health. The original owner drove it only 845 miles and kept it plugged in. The battery charges to 181standard/210 ideal - consistent with the PlugInAmerica survey data suggesting that, at least to date, Roadster battery capacity is primarily related to mileage/recharge cycles rather than age. I don't know the CAC yet but that will be interesting to see and I will get it soon. It drives like a dream.

    My first 2 questions:

    1- The car makes many continuous (never-ceasing) sounds while charging, ranging from a soft whirring in the rear to loud and very loud fan sounds intermittently. That was not too surprising or concerning, and it charges exactly in line with expected " time specs" based on the current I use. However I have been surprised that the car continuously (again, never ceases) to make a soft whirring sound even when not charging. It is in the rear/PEM area
    and is soft and pleasant, but ever-present. Whatever is going on, it does not seem to deplete the battery much if at all even when the car is unplugged overnight. And the the car performs magnificently in every way with no warnings or alerts. It has been a bit warm in the wine country this week with ambient temps in the 90s but my garage is 75-77F. So, is continuous never-ceasing whirring normal at 75-77 degrees F ambient temp, even when not sharging? If so, is it likely a hidden PEM fan whirring or the battery coolant circulating, or both?

    2- I will be in Asia for about 6-8 weeks soon and my wife will not drive the car. I will keep it plugged in and of course in storage mode. Which charger would be the best of my 3 options: The MC-120 Level 1, the MC-240 Level 2 (30A output) or my Clipper Creek HCS-40 (32A output)? The car did come with a brand new and very robust-looking TS-70 HPWC (Tesla branded but made for them by Clipper Creek) but I don't think I'll install it as I should rarely if ever need a really quick charge at home.

    Many thanks for any thoughts on these questions and once again thanks for the wealth of info, experience, and insight that you have all contributed to the Roadster Forum over the years!
     

    Attached Files:

  2. Habious

    Habious Member

    Joined:
    Sep 30, 2014
    Messages:
    408
    Location:
    Springfield, VA
    There's a fain (or a pair of fans, depending on the car) for the PEM. The PEM fan(s) are located underneath the back of the car. These run as-needed to cool down the PEM. You'll hear them kick on and off intermittently both during charging and also during hard driving.

    Likewise, there's a pair of fans up front that also kick on and off as-needed. These are much noisier.

    The pleasant "whirring" sound you hear from the back of the car is the coolant pump. If you let the car sit long enough (and ambient temp allows for it), the car will eventually go to sleep and the pump will shut off - and it will be COMPLETELY silent. But, this doesn't always happen, especially during the summer months.
     
  3. djf

    djf Member

    Joined:
    Jul 15, 2015
    Messages:
    33
    Location:
    Santa Rosa, CA
    Thanks Habious! That fits my observations EXACTLY. If I listen closely and hard, I think I can actually hear a faint "gurgling" consistent with the coolant circulation. Also consistent is the fact that to the best of my recollection the car did fully "sleep" last week before the heat wave. I'm a little surprised that at 75 degrees in my garage the coolant needs to circulate ceaselessly even when not charging, but I guess that's about where the threshold is, since it didn't do so a few days ago when it was a degree or two cooler in the garage. BTW: Is the coolant circulation used for PEM cooling as well as battery cooling, or solely for battery cooling? Thanks again!
     
  4. ggr

    ggr Roadster R80 537, SigS P85 29

    Joined:
    Mar 24, 2011
    Messages:
    2,473
    Only the battery is liquid-cooled in the Roadster. The PEM is cooled by two (original) or one big (upgrade) fan, and I believe the motor is just cooled by ambient airflow.
     
  5. gregd

    gregd Member

    Joined:
    Dec 31, 2014
    Messages:
    574
    It can take some time for the battery to cool down enough (reportedly 30c) for the circulation pump to turn off by itself. Think of it - you've got close to half a ton of metal and liquid in a sealed box, and no real place for the heat to go quickly. One trick I learned here on the Forum is that you can do a short (an hour or so) range mode charge, stopping before the battery is really full. During any charge cycle, if the battery gets too warm, the car kicks on the Air Conditioning to cool the battery. That's when you hear the loudest roar from the car, with the front fans running. (It will also do this when you're driving, switching the A/C to the battery side, which can be a little annoying if you're warm too.) Range mode charging puts a priority on keeping the battery cool, so it will usually let the pump turn off when all the fuss is over, instead of letting it run for a few days.

    My strategy on hot days is to standard-charge the car at my work place, drive home, and do a range charge for an hour or so. Usually that gives me about a standard-mode full battery, but without the pump running. I just need to monitor things so I don't let it go all the way to range-mode full, which will stress the battery. On cool days, I don't bother to charge at home, letting my employer pay for all the electrons. :smile:
     
  6. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,250
    Location:
    Silicon Valley
  7. hcsharp

    hcsharp Active Member

    Joined:
    Jun 7, 2011
    Messages:
    2,532
    Location:
    Vermont
    Congrats on your new ride! You received some conflicting answers so I'd like to clarify. I'm not sure everyone knows you have a 1.5. The 1.5s had one fan for the PEM and one for the motor. Unlike the 2.x Roadsters, the 1.5s have the PEM fan up at the same level as the PEM. It's completely separate from the motor fan which is down low behind the motor. The 2.x Roadsters have both the motor and PEM fans at the bottom back of the car. There was a fan upgrade to the 2.x Roadsters that resulted in still having 2 fans but they are both run by one fan motor. I don't think there was ever a fan upgrade for the 1.5s.

    The fans in front are for the AC condenser which is used to cool both the battery coolant and the cabin.

    As somebody mentioned, the circulator pump will run continuously if your battery is above about 30C. If your battery is that warm, it's a good idea to cool it off using OVMS or just start a range-mode charge at low amperage (12 - 16A) for 30 to 60 minutes. Then stop and revert to standard charge for your regularly scheduled charging.

    I recommend the HCS-40 because it is the most reliable charger you own and you don't want your car to quit charging 2 days after you leave with potentially disastrous results. If it's as hot as you say then the circulator may be running a lot and deplete your battery quicker than normal if not plugged in.
     
  8. djf

    djf Member

    Joined:
    Jul 15, 2015
    Messages:
    33
    Location:
    Santa Rosa, CA
    -----------------
    Thanks all - super-helpful. I tried gregd's trick and it indeed shuts off the fans (in fact immediately when switching from Standard to Range mode on the Charge Screen).
    The coolant pump also finally shut off (after 22 hours!) - but just for about 5 minutes after completing a 1-hour incomplete range charge. Then it resumed its whirring and gentle gurgling. So my thought is that indeed the Range Mode charge is a super-cooling process that can help cool a battery fairly quickly and thus shut off the coolant pump. Thanks for that, gregd. But it seems that after the Range Charge with its inherent cooling is completed, the battery warms up just a tad if ambient temps are warm - and the coolant pump kicks in again. This is quirky but fine with me as it seems to signal that I have a well-functioning and not malfunctioning system! I imagine that on less sweltering days with my garage temp a few degrees cooler the endless coolant pump whir will abate. I also noticed another quirk: with the trunk lid up the coolant pump shuts off after about 5 mins, and when it is closed it resumes again almost immediately. Temperature-related?

    BTW I have read in prior discussions that the battery coolant pump threshold is 26C (about 79F) rather than 30 (about 86F). The former would be more consistent with what I'm seeing as my garage is in the mid-to-upper 70s with the current heat wave. In any event, this is all part of getting to know Roadster #243 as we begin our never-dull (but hopefully not tumultuous) relationship!

    - - - Updated - - -

    ---------
    Thanks for all the great info Henry! I used the HCS40 for the Range Mode "Cool-down" charge and next time I'll use the MC-120 or lower the amps with the HCS-40 as per your instructions to go with low amperage. I will also use the HCS-40 when in storage mode as I agree it is a solid workhorse. Would you recommend turning down the amps when using the HCS-40 in storage mode? How low?

    Fortunately this is a rare heat wave and it usually cools down nicely at night here in Sonoma since we get the cool breeze from the Sonoma Coast. It is highly unlikely it will be anywhere near this warm when I am away. I think everything I am seeing now is a reflection of a well-functioning system in the setting of an unusual heat wave.

    Finally let me note that the option to use the HCS-40 only exists thanks to YOU - I am a proud new owner of a Can-JR - THANKS again.
     
  9. Habious

    Habious Member

    Joined:
    Sep 30, 2014
    Messages:
    408
    Location:
    Springfield, VA
    When the car gets to its happy temp (30C if what others have said - I don't know enough to say otherwise), the coolant pump shuts off and the car goes to "sleep".

    If you "wake the car up", the coolant pump will start going again, as the car is assuming you're about to go for a drive. You can wake the car up by pushing the door release buttons, opening the trunk, closing the trunk, opening/closing the charge port door, pressing a button on the key fob, etc. Basically "touching" the car will wake it up from sleep and cause the coolant pump to start running.

    As a side-note, I have a head's up speedometer on my dash. It's wired into the 12V aux circuit (same circuit as the cigarette lighter plug in the center console). The 12V aux is also on/off when the car is awake/asleep. So, if you have, say, a dash cam or something like that hooked up to the aux 12V line, it'll be on/off depending on the sleep state of the car. I mention the HUD speedometer only because it gives me a visual indication of the car's sleep state. If the HUD is lit up, the car is "awake".
     
  10. djf

    djf Member

    Joined:
    Jul 15, 2015
    Messages:
    33
    Location:
    Santa Rosa, CA
    Thanks once again, Habious. I've had many roadsters, from my MGB in the 70s to my Boxster in the new millennium. This baby clearly has the most complex "personality" of all. Understanding the diurnal rhythms and sleep-wake cycles as you metaphorically (and aptly) refer to them is key. It's cooled down here and she is "sleeping" like a baby.
    I like the HUD speedometer as a sleep/wake indicator - I'll have to look into that.
     
  11. supersnoop

    supersnoop Tesla Roadster #334

    Joined:
    Mar 24, 2014
    Messages:
    825
    Location:
    Pflugerville
    Also note that the 1.5 uses the motor to charge. So, that's some of the noise. But the a/c is by far the loudest noise.
     
  12. slcasner

    slcasner Member

    Joined:
    Feb 20, 2011
    Messages:
    561
    Location:
    Sunnyvale, CA
    The motor is just a coil in the circuit when charging; it does not move. How would that create more noise than the transformer that is in the later cars?
     
  13. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
    I do not understand what you mean. Please explain how the 1.5 motor makes noise when the car is charging.
     
  14. spaceballs

    spaceballs Member

    Joined:
    Sep 17, 2013
    Messages:
    533
    Location:
    Sammamish
  15. Doug_G

    Doug_G Lead Moderator

    Joined:
    Apr 2, 2010
    Messages:
    15,850
    Location:
    Ottawa, Canada
    The A/C really howls when you charge the car at 70A in warm temperatures. That's one reason I lower my charge rate to 40A. (That and it's a little more efficient at 30-40A.)

    The Roadster is far noisier when charging than when driving! Model S is always pretty quiet... well maybe some noise when Supercharging in the heat.
     
  16. tonybelding

    tonybelding Active Member

    Joined:
    Aug 17, 2006
    Messages:
    1,091
    Location:
    Hamilton, Texas
    My 2.5 spends a lot of its time burbling and humming to itself. It's only noticeable indoors, where the confined space of my garage amplifies the sounds. Also... Has anybody else noticed the sounds the power brakes make? I've never noticed it outdoors, but in my garage, when I start up the car and depress the pedal, the brakes make a slightly alarming GRONNNNNK noise.
     
  17. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
    Thank you for the link. That article says: "As the wire that makes up the coil passes a variable current, a varying magnetic field exists around the coil. Forces due to this magnetic field can cause vibration of the coil wires or the core of the coil".
    However, up thread it was stated that during Roadster charging the motor makes noise. I thought that during charging the current is routed through the inverter to the battery. Does current actually pass through the motor during charging, meaning the motor is in the charging circuit? Just want to understand the circuit better. I'm not an EE.
    That post implies that the 2.0 and later Roadsters do not "use" the motor to charge (by "use" does that mean the motor is in the charging circuit?). Is that correct?
    Thanks.
     
  18. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,250
    Location:
    Silicon Valley
    #18 TEG, Jul 31, 2015
    Last edited: Jul 31, 2015

    AC Propulsion's Reductive™ Charger


    Did Roaster use AC Propulsion Technology?

    Basically the motor windings are used as a coil in the circuit so that they don't have to use a redundant coil in the charger itself.
    It saves weight by re-purposing the motor when the car is stopped.

    Reports were that Tesla redesigned the 2.x Roadster to avoid the need to continue to pay AC Propulsion royalties on those related patents.
    I would assume this means that they added some components in the 2nd gen PEM so that they didn't need to use the motor windings anymore.
    Also, they may have been able to remove some electrical isolation components from the 2.x motor if it wasn't part of the charging circuit anymore.
     
  19. strider

    strider Active Member

    Joined:
    Oct 20, 2010
    Messages:
    2,918
    Location:
    NE Oklahoma
    Yep. Older Model S's do the same thing. That's because the brakes are still vacuum boosted. But since there's no engine to provide vacuum like in an ICE there's an electric motor to create the vacuum. That's what you're hearing - every time you release the brake pedal the motor kicks on to rebuild the vacuum. Newer Model S's have cut out the middle vacuum step and just use an electric motor to provide the brake boost. So they just hear the clicking of relays.
     
  20. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,326
    Location:
    San Mateo, CA
    Thanks TEG, I was not aware of this. Yet another difference between the 1.5 and the later Roadsters. Though from the perspective of the owner it's not a difference that is noticed much.
     

Share This Page