Collection of Roadster Tips April 25, 2023
The Tesla Roadster is an iconic little two seater sports car originally slated to be a Lotus Elise conversion to EV by Tesla.
A number of miscalculations turned the car into a custom vehicle, with only 7% of it still Lotus. Fortunately, Tesla recreated body panels, and made frame modification preserving the original look and feel of the sporty Lotus Elise.
This is a collection of tips, gathered from years of Roadster Newsletters.
We are always available either by phone, 800 658-5883 Extension 500, or email ev@gruber.com, for free tech support.
As always, our goal is to support the Roadster community. We believe in transparency, and are committed to vehicle owner education.
TIP - Charging settings to avoid
In Storage Mode setting, the vehicle will ‘wake up’ every 24 hours and if necessary, restart charging to
top-up the battery charge level to a reduced rate, about 20% charge.
The problem is that the vehicle’s cells, charged to a reduced level have little margin for error. In case of an unattended power failure, many Roadsters have been bricked in this state since the time from reduced full State of Charge (SOC) to zero is very brief.
TIP - The VIN story is still unfolding
There is a contradiction in this VIN decoder, between the prefix description claiming all VINs starting in SFZ were 100% manufactured in Hethel UK, vs the 11th digit which indicates a "3" confirms this status. We are aware of a number of early SFZ VIN cars that have a "1" in the 11th digit,
We are still gathering information from owners, Lotus, and Tesla employees, to shed light on this issue.
TIP - Legacy ESS Main Battery Pack Advice
In conversations with JB Straubel, the CTO of Tesla for over a decade, and heavily involved in the Roadster battery pack design, he admits the pack was designed for a 10 year service life. We are all pleased and surprised many Roadsters with original battery packs are still going strong after 14 years.
However, since the cells are marginalized by age, we do not recommend doing any more range charging, or depleting state of charge below 30 miles range. Keeping the yellow charge cable plugged into the Roadster when parked is the safest way to preserve the pack until replacement to the Tesla 3.0 pack
TIP - How to Preserve Your Legacy Roadster Battery
Our Roadster battery repair services require a fair share of research and development, as we are now observing and reacting to aging pack issues and behavior. This is beginning to reveal some interesting data, vulnerabilities, all related to preserving legacy Roadster packs aged 10 to 12 years.
We saw an interesting pattern emerge as we reviewed numerous log file histories. A pattern, suggesting bricks that have even barely perceptible resistive cells, cause brick readings that are ever so slightly lower than other bricks, often holding voltage for long periods of time. Reviewing log file history, this discovery led us to the conclusion that although the brick remains stable, this is usually the first brick with a dying cell later on. (Log file analysis is a free service we offer)
Secondarily, as these battery packs age, watch your depth of discharge. Avoid running your range miles down to low levels. One of the methods we have discovered to flush out marginal cells, is by doing a deep discharge, comparable to running the range down on a Roadster. Our recommendation with legacy packs is to limit the low range or state of charge (SOC) excursions and use a smaller percentage of your battery. Considering the influence charging conditions have on aged cells, to preserve legacy Roadster pack life while we wait for a replacement solution, we recommend charging only in standard mode.
For storage, keep the pack topped off rather than let the SOC drain for storage mode. Avoid using Storage Mode since the distance/time to a bricked state is short. Also, avoid using the yellow 120 VAC charge cable, since the GFCI plugs often fail and sometimes brick Roadsters in the process. The optimum charge program is using the Roadster UMC 240VAC charge cable and setting your charge amperage to 12-15 Amps. Although a much slower charge, rapid charging stresses the cells more. A current Tesla wall/mobile charger set to 12-15 Amps, with a CANSR is another gentle way to keep your pack healthy.
If you have a CHADEMO, JDEMO, or any fast charging conversion on your Roadster with a legacy pack, refrain from use since fast DC charging also stresses the cells.
TIP - Do not use impact wrenches on Roadster keyed lock nuts
The amount of force they apply to loosen or tighten these lug nuts is extensive. It is sufficient to cause locking wheel nut keys/fasteners and tools to break.
Actually, the impact wrench does not provide constant torque. Instead, it is more akin to putting a wrench on the nut or bolt that needs to be loosened and hitting it with a hammer, turning it in small, incremental stages. As power is applied to the impact wrench, an internal "hammer" strikes against an anvil, which is connected to the square drive on the end of the wrench. This attempts to force the tool (usually a socket) that is attached to the air drive to turn.
The sheer power of the impact wrench can damage the locking wheel nut key, and can also damage the locking wheel nuts. Instead, the locking wheel nuts need to be tightened by hand, using a calibrated ‘Torque Wrench’.
Finally, at publication, we are unaware of any Tesla Roadster wheels ever stolen. There is no standard lug nut key for the Roadster. There are actually dozens of variations, mostly hard to find and replace, and often sourced in the UK. We routinely replace them with matching standard original non-keyed TORX lug nuts to eliminate the hassle and risk of breaking.
TIP - Charging Cable and Extension Cords
The yellow 120 VAC charging cable is only 10' long, and it is tempting to use an extension cord when the outlet is too far away. We have seen Roadsters get bricked due to improperly sized extension cords in use for charging.
The yellow charge cable needs a full 15 Amps to properly operate, and be on a dedicated circuit which is not likely in a residential setting where multiple outlets are "daisy-chained" or shared with other devices. Further, most off-the-shelf extension cords are only 16 gauge (7 Amps) which is cannot be used to charge a Roadster. They will overheat. Extension cords should be 50' or less. Here is a table for proper sizing:
18 Gauge Extension Cord - 5 Amps
16 Gauge Extension Cord - 7 Amps
14 Gauge Extension Cord - 12 Amps
12 Gauge Extension Cord - 16 Amps (Minimum recommended size)
10 Gauge Extension Cord - 22 Amps (Ideal size)
TIP - Wheel Lock Key Tip
This little Lotus leftover can cause a lot of grief, both when you lose one (they are hard to find) and if you strip one (even worse).
The ideal solution is to remove them and replace them with non-locking wheel lug bolts, but if you find yourself in a predicament without this wheel lock key, and you need to get your wheels off, here is a trick:
Find a 22mm 12 point long socket, 1/2" drive, as narrow as possible, and using a 2 lb sledge hammer, slam that socket onto the keyed lock nut until it bottoms out.
To remove the lock, put the 22mm socket with fused lock nut into a 23mm socket and use a hammer and punch to knock the lock nut out of the 22mm socket.
TIP - Range Mode Charge
Under normal usage, you do not need to range charge to balance your main battery. The only reason to range charge for re-balancing is when the battery is so far out of balance one brick can't maintain the minimum voltage required for balancing, like after a sheet replacement. Standard mode is plenty sufficient to keep it balanced.
Keep it plugged in and it will wake up every 24 hours to charge and balance itself.
TIP - Fluid Replacement
Battery coolant and brake fluid are flushed every fourth annual. So, the going replacement rate is about every four years. The brake fluid is easier to tell when change is necessary by simply viewing the color of the fluid.
The darker the fluid gets, the more moisture it has absorbed. The typical replacement color is that of a cup of tea, but don't wait until it resembles a Coca-cola color.
TIP - Overheating Roadsters
The 1.5 Roadsters, VINs 1-500, are especially sensitive to overheating during hot summer months. Certain areas of the globe, in high temperature summer climates like UAE, southern Arizona, where temperatures can exceed 100F, 1.5 Roadsters not only reach power limiting during driving, but will also prevent charging since the battery temps are often are beyond what the firmware considers a safe environment to charge.
Our recommendation for charging is to open the rear trunk lid before charging, allowing more air to circulate around the 1.5 PEM, and do your charging at night.
If the 1.5 series Roadster is being serviced, it is a good practice to replace the 12V DC Brush Motor coolant pump, along with the PEM cooling fan every 5 years./p>
TIP - 12 Volt Battery in the trunk
There is an AGM 12 Volt motorcycle battery buried underneath the right front headlight, behind a fender skirt, which powers all the 12 volt devices in the Roadster. These batteries need to be replaced every two years, which is usually a trip to a Tesla Service Center.
We have developed a battery relocation to the trunk, in an accessible housing, with a meter showing battery condition. Replacement now is DIY, and takes only a few minutes.
TIP - ESS Battery Pack Coolant Tip
We have had two Roadsters where coolant reservoirs were nearly empty. Both were exhibiting noisy pumps. In one case, the low coolant level, and subsequent ESS pack overheating, caused an APS (DC-DC Converter inside the ESS pack) to fail.
The solution from Tesla was a $30K ESS pack replacement. We pulled the battery pack and repaired the APS to component level. Pay attention to your coolant levels.
TIP - Do not use Storage Mode
Roadsters can be placed into storage mode charging. With this feature, the battery gradually trickles down to and maintains a 20% state of charge, the advantage being prolonged battery life.
The disadvantage is that if an interruption to charging occurs, the trip from 20% to 0% can be very brief and if not caught in time, a bricked Roadster is the result. We have seen Roadsters brick from this scenario.
TIP - A few extra miles
When the Roadsters battery is fully depleted while driving, the vehicle switches to RESERVE mode which provides you with the opportunity to immediately get the vehicle off the road.
The distance you can drive in RESERVE mode is very limited (depending on the age of the battery, road conditions and grade, or energy being used, this distance could be as little as 1 mile) Play it safe and have your car towed.
TIP - ESS Battery Pack Coolant
The Roadster uses a very specific coolant type. Sierra propylene glycol coolant which has a fluorescent green color. Zerex G48 ethylene glycol coolant, more commonly used in the newer Tesla models, has a dark blue color and should not be used or blended with the existing coolant.
Propylene glycol is used because it is less toxic than ethylene glycol, but ethylene glycol has better thermal conductivity.
TIP - Key FOBs
Roadster key FOB’s do not have a great range. A declining battery can compound this problem. Make sure you replace your FOB battery at least once every year. The battery type is a common CR2032. You can program the top FOB button to perform one of the following:
Sound a one minute alarm - Activate the trunk release - Operate a Homelink device such as your garage door.
TIP - Winterizing your Roadster
For those of you who store your Roadster over the winter, keep an eye on charge levels, and keep it plugged into the charge cable. We have had several owners contact us this past spring with bricked ESS packs, usually due to power issues, charge cable issues, blown breakers, etc.
Get the cell phone accessible OVMS alert system, or make sure to check your stored car weekly!
TIP - Roadster Charge Port Care
The Roadster charge port is a high current connecting point which periodically requires cleaning and lubrication. Deoxit Spray Contact Cleaner cleans and chemically improves conductivity, deoxidizes, reduces wear and abrasion.
Both Socket & charge cable plug need this maintenance. Use compressed air and Q-Tips to clean out recessed areas after spraying on Deoxit, and finish the job by applying a Teflon lubricant like a McLube product.
TIP - Roadster Brakes
Roadster brakes are undersized, and regenerative braking means brakes do not get enough of a workout.
Go out to a deserted paved road and do several HARD STOPS - Emergency-level stops, hard enough to trigger
the ABS. Do this until the rotor surfaces gleam like mirrors, and then do it periodically to maintain them.
The result will be night-and-day in terms of braking performance.
It might just save you from a collision.
TIP - Password for Roadster Diagnostic Screen
A common question we are asked is what the “password” is to gain access to the maintenance/diagnostic screen in the Tesla Roadster.
This is useful to reset “maintenance required” alerts, provide battery condition information, etc.
The password is 1050. (The street address for the San Carlos factory - 1050 Bing Street)
TIP - Tire Warranty
Roadster tires are different diameters with 16” front and 17“ rear tires.
Most tire manufacturers are willing to warranty tires for 40K miles, provided you bring the vehicle in for periodic tire rotation, not possible on a Roadster due to dissimilar tires front/rear.
The fallback then becomes a 20K mile warranty which is still quite generous considering you are wearing tires during acceleration, and regen braking.
TIP - Roadsters sometimes lose their mind
This can be caused by a number of factors including a low voltage instrumentation battery is on its way out.
As simple and effective system reboot is opening and closing the charge port door 7-10 times which often clears errors and allows you to get to a service center.
