Damp cloth on super charger handle to reduce ramp down?

[scottf200]

Bogus test since the kW are high at the start and low at the end.
Only way to compare is to have two cars at the same battery level side by side.
Or do it a whole bunch of times with and without cooling cloth and note the battery level, temp and KW (lot of work to really figure it out).

I think Kyle's care dropped to a low kW when the SOC was pretty low. He switched pedestals and used a cold napkin/towel/something while it was still at the low SOC. That is when he saw the kW start higher and stay higher compared to the other pedestal. I'm pretty sure he commented about using this technique a few times.

 

[mswlogo]

I think Kyle's care dropped to a low kW when the SOC was pretty low. He switched pedestals and used a cold napkin/towel/something while it was still at the low SOC. That is when he saw the kW start higher and stay higher compared to the other pedestal. I'm pretty sure he commented about using this technique a few times.

You just can’t assume anything. The same exact thing could have happened with no cloth. In fact that is exactly what a lot of folks suggest to do to get higher kw (plug into another stall). You need a better controlled test to know for sure.

 

[sacfan]

This may well have been addressed many times elsewhere (if so, would someone please direct me accordingly) but why is it so friiggin slow to squeeze the last 15-20 miles or so of charge in at a Supercharger?

Last night before heading off on a long trip to get back home, the sc started at a rate of 400+ miles/hour for a while, dropped to about 200-250 miles/hour for most of the time, but for the last needed 30 miles of desired charge, despite a rate of 60 miles/hour it just seemed like no matter how long I charged I was just never going to reach “full”.

is this the way it is supposed to work (I assume yes) and why? I ended up charging the last 25 miles via a 110v plug at the rental house that evening before driving home yesterday morning from San Diego to Sacramento in 110-115° F heat.

 

[juliusa]

My test was charging in the hot sun. Charge dropped to 60kW. Put cloth on handle and kW rose to 95kW.

 

[scottf200]

You just can’t assume anything. The same exact thing could have happened with no cloth. In fact that is exactly what a lot of folks suggest to do to get higher kw (plug into another stall). You need a better controlled test to know for sure.

I agree it should be a repeated 'controlled' test. I've seen many post of people plugging into another pedestal to try to get a higher kW, however, the kW quickly drops back down after a few minutes. This is often due to SOC % or problems at the location (utility restrictions). This problem of the handle is a completely different scenario.

 

[scottf200]

This may well have been addressed many times elsewhere (if so, would someone please direct me accordingly) but why is it so friiggin slow to squeeze the last 15-20 miles or so of charge in at a Supercharger?

Last night before heading off on a long trip to get back home, the sc started at a rate of 400+ miles/hour for a while, dropped to about 200-250 miles/hour for most of the time, but for the last needed 30 miles of desired charge, despite a rate of 60 miles/hour it just seemed like no matter how long I charged I was just never going to reach “full”.

is this the way it is supposed to work (I assume yes) and why? I ended up charging the last 25 miles via a 110v plug at the rental house that evening before driving home yesterday morning from San Diego to Sacramento in 110-115° F heat.

This is not the purpose of this thread or the topic of it. This is very basic charging scenario on all EVs. Go read: https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries Charging up to ~80% is fast. "Charging a battery is most effective when its state-of-charge (SoC) is low. Charge acceptance decreases when the battery reaches a SoC of 70% and higher. A fully charged battery can no longer convert electric energy into chemical energy and charge must be lowered to trickle or terminated."

 

[RedXowner]

Charge acceptance decreases when the battery reaches a SoC of 70% and higher. A fully charged battery can no longer convert electric energy into chemical energy and charge must be lowered to trickle or terminated."

This is true with all batteries of all types: lead acid, lithium ion, etc. The battery must be trickle charged for the last/final % of charge. That's why the preferred method, if possible, is to charge more frequently. Keep your battery between 20-80% SOC, drive faster between charges, and you'll spend less overall time charging while keeping your battery in its "zone of comfort." Lithium ion batteries will last longer (accept more charges in their liftetime) when you don't continuously charge them above 90%. Doing this a few times has no noticeable effect, but avoiding it when you can helps both you (time) and the battery.

 

[captanzuelo]

Charge acceptance decreases when the battery reaches a SoC of 70% and higher.

With that info in mind, the parameters for my experiment will be 1st half of the charge from 40%-55% without a wet towel. 2nd half of the charge from 55%-70% with a wet towel. I am hesitant to hop to a different charger for the 2nd half of this experiment because, as others have pointed out, different chargers may have different charge rates.

 

[mswlogo]

With that info in mind, the parameters for my experiment will be 1st half of the charge from 40%-55% without a wet towel. 2nd half of the charge from 55%-70% with a wet towel. I am hesitant to hop to a different charger for the 2nd half of this experiment because, as others have pointed out, different chargers may have different charge rates.

I don’t think it’s so much chargers themselves vary (assuming no buddy is connected on the same pair). But I think it’s more to do with restarting at different conditions. Battery warmer (which can be a good thing) and SOC higher at the start of the charge.

 

[HenryFarkas]

Ok...time to research. 10 minutes goes by. Ah...not so good in high humidity such as Houston where I live. Might try it anyways.

If you know you're going the supercharge in a humid environment, bring a picnic chest with ice cubes. Then, put the ice cubes in a plastic bag and rest it on top of the charge handle during charging if you see the charge rate slowing down due to heat in the charge handle.

 

[captanzuelo]

Okay, the wet towel did nothing for my charge at a 120kWh supercharger today. Perhaps it was because I was in a covered charging spot? I plugged in at 45% SOC and noted 116kWh charge rate. After 10 minutes it gradually decreased to 89kWh. At this point, I slapped a cold wet towel over the charging handle. The charge rate just continued to decrease until reaching 56kWh for the last five minutes of the charge.

 

[juliusa]

Okay, the wet towel did nothing for my charge at a 120kWh supercharger today. Perhaps it was because I was in a covered charging spot? I plugged in at 45% SOC and noted 116kWh charge rate. After 10 minutes it gradually decreased to 89kWh. At this point, I slapped a cold wet towel over the charging handle. The charge rate just continued to decrease until reaching 56kWh for the last five minutes of the charge.

Cold towel does not affect normal taper due to SOC. It simply cools the handle to lessen taper due to a hot handle.

 

[Only Trons]

Superchargers Visited

@Big Earl posted about using this trick in his Model 3 on a long trip earlier this year. Posted in Superchargers Visited thread.

 

[njhtran]

Yup had the same issue stuck in the middle of nowhere near lake Isabella ca with 4 stations all Of them empty. It started at 150mph then dropped to 60mph at about 70% and I needed absolutely all I could muster to get to Ontario where the next station is. With absolutely nothing to do but sit in the car it pretty much ruined any idea of me wanting to go anywhere far with a Tesla until the range is improved.

 

[Ludalicious]

Anybody else think it's a bad idea trying to fool heat sensors. The current supercharger cables already have a cooling system according to the patent... But this just sounds plain stupid.

 

[ElectricIAC]

Yup had the same issue stuck in the middle of nowhere near lake Isabella ca with 4 stations all Of them empty. It started at 150mph then dropped to 60mph at about 70% and I needed absolutely all I could muster to get to Ontario where the next station is. With absolutely nothing to do but sit in the car it pretty much ruined any idea of me wanting to go anywhere far with a Tesla until the range is improved.

Sounds like someone’s been throttled!

In any case: this trick seems to work best in hot dry climates as I’ve noticed early taper when starting at a very low SoC.

 

[njhtran]

Sounds like someone’s been throttled!

In any case: this trick seems to work best in hot dry climates as I’ve noticed early taper when starting at a very low SoC.

any idea why i've been throttle? i do get a lot faster (250mph) at other stations tho. And I rarely use superchargers at all

 

[Ludalicious]

Sounds like someone’s been throttled!

In any case: this trick seems to work best in hot dry climates as I’ve noticed early taper when starting at a very low SoC.

Drink some more KoolAid. Theirs a reason why there is a sensor in the cable. So it doesn't over heat due to temperature. Artificially introducing a lower temp at the sensor is complete idiotic. This is the stupidest thing I have read on TMC since people started painting their rotors on the vehicle. Congratulations this is now officially the dumbest thing I have read on here.

 

[ElectricIAC]

any idea why i've been throttle? i do get a lot faster (250mph) at other stations tho. And I rarely use superchargers at all

SoC is pretty important but also pack.

 

[juliusa]

The V3 superchargers have cooling in the handle. V2 need some help from a wet cloth to cool the handle and keep the charge rate up.