100% or 80%.... myth?? [preparing for a road trip]

[rengel79]

Ok but it still charges the battery? I plugged the car in yesterday- set the car charge to 10amps telling me it would charge from 30% (where the battery was) to 80% in 17 hrs which it did. Given I’m paying 26c per kWh for power my assumption was doing the 10amp would be more cost efficient than 32amp charging. Good to know!

 

[CaseyL]

Do not for example charge up to 90% or more percentage in the evening before your trip and then drive out early morning as having a high load, meaning high charge over 80 percentile is bad for the battery health.

I do this frequently before a road trip. It's fine. There is no magic difference in 80% and 90%.

Here is how he laid out the scenario: Let's say you want to drive over 200 miles tomorrow morning at 7.00am and your charge is at 50% today. Leave it at 20% - 50% order night, get up a little earlier and head to your closest super charger station at about 6:00am for that 100% charge. Then within 5-10 minutes after the charging is completed you want to drive long range. Do Not Wait an hour to drive. A big no.

This advice is just flat out wrong.

Talk about making things complicated ... just charge to 90% or 100% the night before. Leave when you feel like. Don't rush.

If using non Superchargers at your location use trickle charge at home but set the schedule to 100% for 7.00am and drive at 7, not 8am!

The battery is not going to blow up.

Don't "trickle charge" at home. Instead, charge at 48 amps or the highest rate possible.

 

[danpass]

80% for regular daily living.

Charging to 100% the day/night before a road trip

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[MichaelSte2022]

80% for regular daily living.

Charging to 100% the day/night before a road trip

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I love this tip. Thanks. Driving far tomorrow early, so I'll top it off in our garage on our slow 1kW 110v charger home plug tonight and grab a super to 98% now. Thanks man.

 

[davewill]

Ok but it still charges the battery? I plugged the car in yesterday- set the car charge to 10amps telling me it would charge from 30% (where the battery was) to 80% in 17 hrs which it did. Given I’m paying 26c per kWh for power my assumption was doing the 10amp would be more cost efficient than 32amp charging. Good to know!

It does. The remark about not really charging the car in cold weather was aimed at people here in the U.S. charging at 120v. 240v@10a is going to charge your car in pretty much all situations, although in freezing temps it might be kinda slow. Anyway, the main thing to know is that for home charging, FASTER is always more efficient, and even the fastest home charging rate is slow as far as this big battery is concerned.

 

[MichaelSte2022]

Thanks all for the feedback here, and just confirming doing a slow charge (e.g at 10amp overnight) with my standard Telsa wall charger is a more cost efficient way of charging (trickle charge) rather than 'blasting' 32amps into it? I've got a single phase, 32AMP circuit connected to my wall charger.

Personally I'm all for the medium trickle charge speeds of 200v-240v depending on the wiring work by the electrician. Superchargers sure they're great however, used only for a few minutes, that practice keeps the battery cooler.

It's the hot heated battery during long sessions of Superchargers charging that leads to less lifespan, similar to a cellphone battery. Heat wear, the key terminology here.

Please chime in if I got any facts a bit off here. Should be correct, all of the above.

 

[rengel79]

It does. The remark about not really charging the car in cold weather was aimed at people here in the U.S. charging at 120v. 240v@10a is going to charge your car in pretty much all situations, although in freezing temps it might be kinda slow. Anyway, the main thing to know is that for home charging, FASTER is always more efficient, and even the fastest home charging rate is slow as far as this big battery is concerned.

Thanks @davewill - I'm based in Melbourne, Victoria (Australia) currently winter here and our days hover around 15c and at night 3-4c so not super cold. I honestly thought I was saving more money by not charging at 32amp and rather turning down the charging to 10amp and letting it charge overnight... (thinking less amps = less kilowatts per hour charging if I was charging at 10amp vs 32amp). guess I was wrong!

 

[rengel79]

Personally I'm all for the medium trickle charge speeds of 200v-240v depending on the wiring work by the electrician. Superchargers sure they're great however, used only for a few minutes, that practice keeps the battery cooler.

It's the hot heated battery during long sessions of Superchargers charging that leads to less lifespan, similar to a cellphone battery. Heat wear, the key terminology here.

Please chime in if I got any facts a bit off here. Should be correct, all of the above.

Tx @MichaelSte2022 - our wiring work is pretty good.. the electrician did a great job wiring a dedicated single phase, 32amp circuit to our switchboard... never had an issue with it.

 

[ucmndd]

It's the hot heated battery during long sessions of Superchargers charging that leads to less lifespan, similar to a cellphone battery. Heat wear, the key terminology here.

Please chime in if I got any facts a bit off here. Should be correct, all of the above.

Unfortunately you’re still missing the mark. In reality, fast charging a cold battery is far worse than a hot one due to a phenomenon called lithium plating.

This is why the car deliberately preconditions (heats) the battery when navigating to a supercharger and significantly limits supercharging speeds when the battery is cold.