Does anybody adjust their charging amps using app?

[Konicom04]

Maybe it is time to upgrade your electrical service and install a new panel. My home (built in 1963) had a 150 amp fuse panel. I was down with replacing fuses as needed. Then the neutral connection snapped off at the back plane of the panel, held only by the wires pressing against the neutral wire. This happened while I was away. There had been a storm and the power was interrupted for time. When I arrived home I found that half the house had low (really low) voltage, i.e. ~80V when measured at the receptacle and half of the outlets measured higher than 130V It took weeks to troubleshoot and in the meantime I lost a surge protector. Lesson learned; old service panels (my panel was 50 years old) should be replaced. I replaced the service panel shortly afterwards with 200 amp service and a new breaker panel. This happened about 4 years before I purchased my first plug-in vehicle.

Charging at 15 amps when you could be charging at a higher amperage is less efficient.

I do have a new service panel, and dedicated 220V line in my garage

 

[GSP]

I was under the impression (from a thread on this site somewhere) that lower AC amps was actually less efficient than higher?

Early Roadster owners ran tests to see how the charging efficiency changed with AC amperage and found there was a sweet spot. The results were posted here on TMC. I am not sure but @tomsax may have been one of the owners who did this.

At lower current, 8-30ish Amps, the energy used to run cooling pumps etc for the longer charge time made charging less efficient. At high currents 40ish to 70 Amps, the rectification of AC to DC in the charger was less efficient.

I don't remember what the sweet spot was, but IIRC it was in the 30-40 Amp range.

That was for the Roadster's charger. I think early Model S owners did the same test, but I don't remember how that turned out. I have not seen any tests on the "PCS" charger used in modern Teslas, starting with the Model 3.

GSP

 

[jcanoe]

I do have a new service panel, and dedicated 220V line in my garage

I have a 240V, 50 amp circuit and could charge at 40 amps; I choose to charge at 32 amps due to the EVSE I purchased (more compact size.) I see no benefit to charging at lower than 32 amps (7kW charging rate) as this does not excessively heat up the wires, receptacle, EVSE or charging connector.) (The charging circuit is effectively de-rated by 20% from 50 amps to 40 amps, and another 20% from 40 amps to 32 amps.) With even lower amperage the efficiency would be worse due to increased overhead losses.

 

[Konicom04]

I have a 240V, 50 amp circuit and could charge at 40 amps; I choose to charge at 32 amps due to the EVSE I purchased (more compact size.) I see no benefit to charging at lower than 32 amps (7kW charging rate) as this does not excessively heat up the wires, receptacle, EVSE or charging connector.) (The charging circuit is effectively de-rated by 20% from 50 amps to 40 amps, and another 20% from 40 amps to 32 amps.) With even lower amperage the efficiency would be worse due to increased overhead losses.

overhead losses or not - is it better for battery to trickle charge or is 30 to 40 A a sweet spot

 

[GSP]

How influential are Amps on battery life? Its common knowledge that supercharing has negative affect, but I wonder if charging at 40A versus 15A is "beneficial"?

Can someone chime in please

I expect zero impact on battery life from different AC charging speeds.

Anything from 8-80 Amps is still very slow compared to supercharging. Modern Teslas can charge at up to 48 Amps, which is 11.5 kW using 240 V single phase power. This is a C-rate of only 0.14 C for a MYLR, which is very, very easy on the battery. Supercharging uses the max power the battery can accept, up to 250 kW. That is a rate of 3C, which is stressing the battery as much as possible.

GSP

 

[jcanoe]

overhead losses or not - is it better for battery to trickle charge or is 30 to 40 A a sweet spot

Any of the Level 2 (240V) charging amperages, including charging at 48 amps (11kW), are far below the threshold where it could stress the battery (1C where C is the capacity of the battery in kWh, so ~74kW or greater when Supercharging.)

Note: Tesla manages the Supercharger charging session to avoid stressing the battery when Supercharging at levels up to 250kW, ~3C.

 

[LetsGoElectric]

Lesson learned; old service panels (my panel was 50 years old) should be replaced. I replaced the service panel shortly afterwards with 200 amp service and a new breaker panel.

I can certainly do this if you're paying for it. Otherwise, 100 amp service it is.

 

[Konicom04]

Maybe it is time to upgrade your electrical service and install a new panel. My home (built in 1963) had a 150 amp fuse panel. I was down with replacing fuses as needed. Then the neutral connection snapped off at the back plane of the panel, held only by the wires pressing against the neutral wire. This happened while I was away. There had been a storm and the power was interrupted for time. When I arrived home I found that half the house had low (really low) voltage, i.e. ~80V when measured at the receptacle and half of the outlets measured higher than 130V It took weeks to troubleshoot and in the meantime I lost a surge protector. Lesson learned; old service panels (my panel was 50 years old) should be replaced. I replaced the service panel shortly afterwards with 200 amp service and a new breaker panel. This happened about 4 years before I purchased my first plug-in vehicle.

Charging at 15 amps when you could be charging at a higher amperage is less efficient.

Well - my panel replacement story is a bit more drastic. The event also happened before me going electric for my commuting,

One morning while leaving for work i heard an odd noise coming from the basement ( i have an obnoxiously excellent hearing).
Went down to the basement - witnessed flames coming out of the panel. Killed the main switch, made sure no flames / smoke was visible, called my good friend electrician who came in that day and replaced the whole 40 year old panel with a new one.

An amazing coincidence and timing. If i had left without noticing, I suppose i would be living elsewhere by now.

 

[jcanoe]

I can certainly do this if you're paying for it. Otherwise, 100 amp service it is.

Electrical service panels do wear out from age and can become unsafe. When I replaced my 50 year old fuse panel the electrician also performed a heavy up (from 150 to 200 amp service) when installing the new panel.

Someone I know with was having their kitchen remodeled with all new lighting and circuits. They went through weeks of hell working with electricians and the power utility to trouble shoot electrical problems in the home. In the final analysis the meter head was found to have corroded; this was creating all sorts of electrical demons. The house was ~40+ years old

 

[LetsGoElectric]

Electrical service panels do wear out from age and can become unsafe. When I replaced my 50 year old fuse panel the electrician also performed a heavy up (from 150 to 200 amp service) when installing the new panel.

Someone I know with was having their kitchen remodeled with all new lighting and circuits. They went through weeks of hell working with electricians and the power utility to trouble shoot electrical problems in the home. In the final analysis the meter head was found to have corroded; this was creating all sorts of electrical demons. The house was ~40+ years old

100% agree on replacing electrical items that are old and out of date. But the cost to upgrade service from 100 to 150 or 200 ain't cheap.

 

[jcanoe]

100% agree on replacing electrical items that are old and out of date. But the cost to upgrade service from 100 to 150 or 200 ain't cheap.

You can include the cost of replacing/upgrading the service panel in you cost basis when you sell your home.

 

[LetsGoElectric]

You can include the cost of replacing/upgrading the service panel in you cost basis when you sell your home.

Have you seen home prices recently? I don't think I'll ever be able to move.

 

[davewill]

100% agree on replacing electrical items that are old and out of date. But the cost to upgrade service from 100 to 150 or 200 ain't cheap.

Couldn't hurt to get a quote. You might get lucky and find that the incoming cable can support a higher service level.

 

[LetsGoElectric]

Couldn't hurt to get a quote. You might get lucky and find that the incoming cable can support a higher service level.

Very true.

So I did.

Unfortunately, the cable coming into my home can support 100amp service.

 

[DblOSmith]

I charge on a 5/15 outlet. Anything above 9 amps makes the TMC unhappy, so that's where I keep it.

 

[Jerryr]

Because

The power used by the Wall Connector when not charging is just a few watts as with other electronics. The built-in WiFi circuitry uses some power. There is no practical way to turn off the Wall Connector. The circuit breaker is not designed for that type of usage and would not last long if you continually flip the breaker on and off. You could, at some expense, have an electrician install a service disconnect switch close to the Wall Connector. (In some areas the local electrical code requires a service disconnect switch for any hard wired circuit/equipment rated for more than XX amps.)

It could save a few pennies if you flipped off the circuit breaker for the Wall Connector if you are going to be away for many days or weeks.

I have been flipping my 30 amp Double Pole Water Heater breakers off weekly for 40 years and never had a failure. We travel between two homes and never leave water or water heater on when not at home overnight.

Our 14-50 outlet for the RV and the mobile connector is also turned off (Flipped) when not being used. Never had a failure with these either. In fact it's a good practice to never plug in a 50 amp plug to a hot outlet.

I just had a Wall Connector installed and I will turn off the Wall Connector breaker when not in use.

 

[jcanoe]

I have been flipping my 30 amp Double Pole Water Heater breakers off weekly for 40 years and never had a failure. We travel between two homes and never leave water or water heater on when not at home overnight.

Our 14-50 outlet for the RV and the mobile connector is also turned off (Flipped) when not being used. Never had a failure with these either. In fact it's a good practice to never plug in a 50 amp plug to a hot outlet.

I just had a Wall Connector installed and I will turn off the Wall Connector breaker when not in use.

The consensus, here in TMC, is that circuit breakers are not designed for a high duty cycle. Your experience seems to contradict that information. I do flip the circuit breakers in my home, perhaps once a year as I have read that it is good practice to prevent a breaker from sticking closed when it needs to trip, open. Hopefully you will have no issue with regularly turning off the circuit breaker on the TWC when the TWC will not be used for a time.

You are correct that you should always turn off the power before plugging equipment into a 240V circuit, i.e. 240V, 50 amp circuit. It is the consensus on TMC that most NEMA 14-50 receptacles are not designed for a high duty cycle with regular plugging and unplugging. The 14-50 receptacles connection with the power plug may not remain tight after a fairly low number of plug and unplug operations.

I rarely use my home charging circuit 240V/50 amp 14-50 receptacle. There have been periods where I have left the breaker turned off but I now leave the breaker in the on position even though I don't regularly need to charge at home.

 

[Ctuna]

The question I have is would it be more better for battery longevity to charge at lower speed over the long Run. If you have the full 60 amp breaker can you or is it better to charge at lower rates.
Choices are 32 ,40 and 48 amp from the wall connector I guess . Having the flexibility to change the charge rates from time to time might be a good option.

 

[jcanoe]

The question I have is would it be more better for battery longevity to charge at lower speed over the long Run. If you have the full 60 amp breaker can you or is it better to charge at lower rates.
Choices are 32 ,40 and 48 amp from the wall connector I guess . Having the flexibility to change the charge rates from time to time might be a good option.

No, charging at any of the Level 2 charging rates are not high enough to affect the health of the battery in the Tesla Model Y, ~82 kWh total capacity. Level 2 charging maximum is currently 11.5kW (48 amp). This is ~1/7th of the capacity of the battery, C. Charging at up to 1 X C is safe depending on temperature and the battery's state of charge. When Supercharging the Tesla battery can be charged for brief periods at up to 3 X C. Tesla manages the Supercharging session to minimize any stress to the battery.

Some believe that lowering the charging amperage from 48 amps (when available) to 40 amps or 32 amps prolongs the life of the Tesla Wall Connector. I have not read of any long term testing of the TWC. In general quality electric vehicle service equipment (EVSE) have a 3 year manufacturer's warranty. Eventually all EVSE will need to be replaced due to normal wear of the connector or damage to the charging cable.

Tests have shown that charging as fast as the charging circuit enables is more efficient than charging at lower charging rates. There is a fixed overhead while charging of ~230W due to the Tesla Model Y being powere on and also for heat losses in the charging equipment while charging. Completing charging as quickly as possible limits the overhead.

 

[stroked250]

I charge at 32A, just to keep any heat buildup in all the components well below their rating limit. Just a wild guess, but working with battery engineers, I know how they decide on maximum ratings. If there's a built in safety factor that allows for a very very low rate of failure over the design lifetime, and I'm only using 3/4 of that rating, then I'm lowering the chances of failure even more, maybe so low it can't be reliably calculated.

Heat cycling is the enemy. Expansion/contraction of different materials in contact with each other eventually degrades that contact.

But I have no problem charging at full amps if I am ever in a hurry and really need it. Has not happened yet.

Another anecdotal observation: the heat pump seems to kick up into a higher setting at 48A compared to 32A. So there might be something going on with excess heat that they are needing to remove.

I might be totally wrong, and getting no benefit from lowering the amps, but what does it hurt? I still only need a few hours at most, most nights, to get back to 75%, so there's no reason to push it.

Good thought but isn’t the full 48A draw already well below potential. Superchargers are quite a bit more powerful.