Understanding Lithium Battery Charge Cycles: A Complete Guide

A charge cycle refers to the process of discharging a battery and then recharging it back to full capacity. Technically, a complete charge cycle occurs when a battery has discharged to a certain percentage—commonly 100%—and is then charged back to its full capacity. However, it’s important to note that a charge cycle can consist of smaller partial discharges. For instance, if you use 50% of your battery one day and recharge it to full, then use 50% the next day and recharge again, that still counts as one full charge cycle.

So a charge from 0-100% is 1 charge, charging four times from 75%-100% is also 1 charge, and charging ten times from 90%-100% is also 1 charge.

Do note that some lithium batteries do not like to sit with a 100% charge for a long period of time, such as for my Model 3 the suggested daily charge limit is 80%. If I charged it five times from 60%-80% that would be counted as 1 cycle. On a trip it's OK to charge to 100%, just want to hit the road soon after reaching 100%.

Natural gas is still our biggest source of electricity* and heat in Texas, and it's production dropped nearly in half during the freeze:

Regional natural gas production (January 2020-February 2021)

A large portion of the decrease in natural gas production was from declines in Texas, which fell over 10 Bcf/d during the February 8–17 period. Unlike natural gas production infrastructure in northern areas of the country where below-freezing temperatures are more common and infrastructure is generally winterized, wellheads, gathering lines, and even processing facilities in Texas are more susceptible to freeze-offs during periods of extremely cold weather.

The nuclear plant south of me lost half its output:

How and why a nuclear reactor shut down in Texas cold snap when energy was needed most

One of two reactors shut down at the South Texas Nuclear Power Station an hour southwest of Houston, knocking out about half of its 2,700 megawatts of generating capacity.

Interestingly enough, even with all the frozen turbines wind was generating more power than expected when the grid collapsed:

Texas’ power grid crumples under the cold

Since wind in Texas generally tends to produce less during winter, there's no way that the grid operators would have planned for getting 30GW from wind generation; in fact, a chart at ERCOT indicates that wind is producing significantly more than forecast. [see chart, green line is what was generated, blue and red lines below it are what was forecasted]
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An ERCOT director told Bloomberg that problems were widespread across generating sources, including coal, natural gas, and even nuclear plants.

My understanding is it was windier at the coast than expected and those turbines more than compensated for the frozen inland turbines.

* from ERCOT's Fuel Mix report for 2024

- 35% Gas-CC
- 24% Wind
- 13% Coal
- 10% Solar
- 9% Gas (not CC)
- 8% Nuclear
- 1% other

but I'm not going to pretend it's foolproof - during the big freeze the nuclear plant just south of me lost half its output.

How and why a nuclear reactor shut down in Texas cold snap when energy was needed most

The shutdown of a nuclear reactor in Texas has contributed to the state’s power shortage crisis caused by extreme cold weather.

One of two reactors shut down at the South Texas Nuclear Power Station an hour southwest of Houston, knocking out about half of its 2,700 megawatts of generating capacity.

During that same time the snow & ice covered solar panels on my home generated just enough power to keep my gas furnace going, so my home did not freeze and I didn't have to deal with burst water pipes* like many others did. I got up on a ladder and swept off what snow I could reach, without climbing onto the roof itself, and the panels freed themselves of snow and ice by that afternoon even though it stayed below freezing.

* Really wish they didn't do stuff like this with our water pipes - if you're away during an unexpected freeze event you may be coming home to a big problem.

Been roadtripping in a Tesla since getting my Model 3 in 2018. Back then the Superchargers maxed out at 120 kW and during roadtrips to Wisconsin (from Houston) some of the stops would require the slow* 100% charge to reach the next Supercharger. On occasion I'd be prompted to drive slower to extended range, such as between Little Rock Arkansas and Miner Missouri (example of that prompt from a 2019 trip).

Now the newer (2019+) V3 Superchargers max out a 250 kW, plus those older 120 chargers were software updated and now max out at 150 kW. New Superchargers have infilled between older Superchargers, so I haven't needed to do the slow 100% charge in years. A lot of our stops are now:

1) plug in
2) take care of our needs
3) unplug and resume trip

Sometimes we do have to wait a little bit after getting back to the car, which makes those stops comparable to stops we used to have in a gas car when we had to spend time standing next to the car to monitor the refueling process.

The lastest V4 Superchargers currently max out at 325 kW** but not many vehicles support yet such as my Model 3 still tops out at 250 kW when using a V4.

Our longest trip to date was 5000 miles to Yellowstone, onto Tacoma Washington to visit family, then back to Houston. On the route back it was pretty wild to see the car gain range when we were driving down from Monarch Pass in Colorado.

We've been mostly lucky with options around a Supercharger, though on occasion we have encountered restrooms that we didn't want to use - sure am glad that Buc-ee's signed up with Tesla to host Superchargers, really nice for our roadtrips around Texas.

* charging from 0%-80% takes about the same amount of time as charging from 80% to 100%, so it's a waste of time to go past 80% unless you absolutely need it, or are stopped for a meal.

** with plans to go up to 500 kW

I've imported DVDs and Blu-rays of shows from Europe and with Match Frame Rate turned on I no longer experience the 50 fps to 60 fps conversion judder that would show up with my prior setup. The judder was most noticeable when a scene would pan.

Match Frame Rate: Turn on to have Apple TV 4K or Apple TV HD match its refresh rate to the original frame rate of content. This applies to content that's mastered at different frame rates — for example, 24fps film-based content or other international content.*
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*Apple TV matches the frame rate of content encoded at 60, 50, 30, 25, and 24fps. Frame rates match the refresh rate appropriate for your region, for example 29.97fps for NTSC. 25fps and 30fps content uses frame rate doubling to display at 50Hz and 60Hz when available, matching its original appearance while preserving a fluid user interface.

Interesting....thank you!

You're welcome! My folks were skeptical of EVs, but after joining me on a number of road trips they now own a Model Y.

I don't hear the same positive things about other EVs.

I haven't kept up with others, that's a bummer to hear.

The charing...6-7 minutes ok...but once above 12-30 min....not acceptable to me.

Next time you're on a road trip time your stops as you might be surprised, I know I was - from a trip in 2019 at a V2 Supercharger in Alberta Lea, MN.

$8.12 for 126 miles of range in 22 minutes.

The 22 minutes is how long it took us to walk from the back lot to the travel center (with 4 restaurants), visit the restroom, grab some drinks and snacks, and walk back to the car.

"Back lot" sounds far, but it wasn't - check the map at google, be sure to check the photos as well.

I use to keep it wound up to about 95mph or more, but these days, I stay about 80-85mph....

Speed limits are pretty high around in Texas; though living in Houston I don't often get on 130, it connects Austin and San Antonio and has our highest speed limit of 85 mph.

Just curious....does this give you the shortest route...or does it alter the shortest route to make sure you can find charging stations?

Shortest route based on the location of the chargers. If you pause that video at 0:12 you'll see the routine route in 2022 took us thru Dallas, Oklahoma, Missouri, Iowa, and Minnesota before coming in from the west side of Wisconsin. Our most recent trip to visit my brother was thru Texarkana, Arkansas, Missouri, and Illinois, before coming into Wisconsin from the south, saving about 30 miles.

On this trip, each time you needed to recharge...how long did it take?

When I got my first Model 3 in 2018 the Superchargers maxed out at 120 kW. That changed when the V3 Superchargers that max out at 250 kW started to roll out in 2019. Existing V2 Superchargers are still there, though were bumped up to 150 kW. I just checked by having my new Model 3 plan the route and the 7 charging stops would be:

1) 6 minutes in Carthage, TX (V3)
2) 7 minutes in Hope, AR (V3)
3) 12 minutes in Little Rock, AR (V2)
4) 26 minutes in Jonesboro, AR (V3)
5) 21 minutes in Mehlville, MO (V2)
6) 14 minutes in Normal, IL (V3)
7) 19 minutes in South Beloit, IL (V4)

One thing we've learned is not having to stand next to the car to monitor the refueling process means some stops are quicker than getting gas because car's ready to resume to the trip before we're done taking care of bio requirements(which takes way more time than people realize). Some stops are longer, so it ends up being a wash.

Do note that due to the charge curve you don't charge to 100% as it's a waste of time (ie: charging from 80-100% takes as long as charging from 0-80%), so during any stop that the car's ready before you are the car will just continue to charge so you end up leaving with more range than planned for, which reduces time needed at the next charging stop.

I got the Supercharger V# for each stop from Supercharge.info. V4 Superchargers use a new cabinet design with a longer cord to better support other EVs that might have their charge ports in different location than Tesla. Original V4 Supercharger sites use a V3 power supply, so are limited to 250 kW. Newer V4 sites now go up to 500 kW, though my Model 3 will still max out at 250 kW. I believe there's only a handful of EVs, such as the Cybertruck and Taycan, that can currently take advantage of the higher limit.

Was there a line?

I've been road tripping in an EV since 2018 and have only had to wait 3 times for a Supercharger to free up. In each instance the wait was under 5 minutes. I've been queued up significantly longer for gas on many occasions.

Were there any chargers that were out, etc?

The car knows if Superchargers are out, or congested, and will automatically reroute. We were surprised the first time we experienced that - we were on our way to charge in Texarkana when the car suddenly rerouted us to Shreveport. While charging in Shreveport we did an online search and found out a storm had knocked out power in Texarkana. We were rerouted 2 additional times during that trip, once when a Supercharger site was congested, and once when another storm decreased our range via heavy rain and a headwind.

Did you find any stretches on this drive, that were a bit few and far between on charging stations?

Experienced that back in 2018, distances between some Superchargers were far enough that we had to charge to 100% - we'd use to stops for meal breaks to decrease the impact. We would get warnings to drive slower to make it to the next charger such as this example I posted in 2020 from a 2019 trip. I've even drafted a semi to make it to the next charger. Haven't seen those warnings, been required to charge to 100%, nor needed to draft a semi for a few years now.

was it ever a close call on running out of power along the way?

As mentioned above, the car will warn you to drive slower. As an example of how much difference speed makes, this Model 3 with an EPA range of 310 miles was able to achieve 606 miles on a single charge.

don't have plan my driving or trips like I'd have to do with an EV...to me THAT seems like a PITA.

As an example I live in Houston and to visit my brother in central Wisconsin I just:

1) get in the car
2) press the microphone button on the steering wheel
3) say "go to Nekoosa, Wisconsin"
4) confirm the destination
5) start driving

Here's a video of that from 2022.

Longest EV trip we've done so far was 5000 miles to Yellowstone, onto Tacoma Washington, then back to Houston. Only planning we did ahead of time was to book hotel rooms in West Yellowstone and an AirBnB in Tacoma.

I'm only familiar with Tesla, though expect other EVs to be similar such as Ford's Connected Navigation.

It was not something Elon planned to do, he put forth for others to pursue.

From 2013: Elon Musk gives us the goods on Hyperloop

Finally, it should be noted that Musk doesn’t plan on building the Hyperloop himself – he simply wants to get the design out there, for other parties to run with.

"As someone that uses back seats to carry some luggage, I am not a fan of this requirement."

Already solved by Tesla and others. From Tesla's Model 3 manual: Using seat belts and child safety seats

You can temporarily disable a seat belt reminder associated with a rear seating position. This is useful when you are carrying an object in a rear seat that triggers the seat belt reminder alert. To disable the reminder, touch the associated seat on the seat belt reminder popup message that displays on the touchscreen when a seat belt reminder is active. When a reminder is disabled, the seat belt reminder icon is replaced by a seat icon, for the current drive only. Touch the seat again to re-enable the reminder.

Really? My understanding is the overall auto market has declined while EVs have increased.

Despite Tesla Slide, EV Sales in Q2 Mark New Record

Electric vehicle sales in the U.S. grew by 11.3% year over year in the second quarter, reaching a record-high volume of 330,4631 units, according to new estimates from Kelley Blue Book.
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The sales estimates from Kelley Blue Book show that electric vehicles accounted for approximately 8% of total new-vehicle sales in the second quarter, higher than the 7.1% share in the first quarter of the year and higher than the 7.2% recorded in Q2 last year.

EV Sales Forecast To Rise 8% In 3rd Quarter As Overall Market Slows

US auto sales are expected to drop 5.4% for the third quarter.
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Electric-vehicle sales in the US are expected to rise 8% for the third quarter of 2024 over Q3 2023 when sales numbers are released next week, pushing EVs up to nearly 9% market share, Stephanie Valdez Streaty, director of industry insights for Cox Automotive, said during the firm’s industry insights and sales forecast call.

I had a pair for a week, I quite liked being able to play music on them while still being able to clearly hear my surroundings. Also liked using "Hey Meta, what am I looking at", it could even identify plants - one response I had was "You are looking at a pot of red chrysanthemum flowers".

Ended up returning them because the frames were too tight, which gave me headaches. They could not be adjusted like my other frames due to the electronics in the temples (aka the arms).

I plan to check them out again when it's time for my next new pair of glasses, hopefully they'll have added larger frame sizes.

I picked up one of these at Microcenter last month:

Micro Center 512GB Dual Type-A Type-C 2-in-1 SuperSpeed USB 3.2 (Gen 1) Flash Drive - Green

I use a Mac mini as my home theater PC and have used it for video calls in the past, such as when I was interviewed by ZeroPage Homebrew for my Atari 2600 Homebrew games.

Other World Computing has used Mac minis starting at $59.

Was without power for 3+ days after Hurricane Beryl went through the Houston metro. I have solar and 1 PowerWall. The PowerWall can output up to 240v at 30amp which is enough to keep most of my house running, so no spoiled food, but not enough to power the AC unit or regular car charger.

During the day I used fans to keep cool. Once the sun recharged the PowerWall to 100% I'd plug my Model 3 into the dryer outlet to capture the excess solar production. At night I slept in the garage in the Model 3 using Camp Mode to have AC during the night without fear of carbon monoxide poisoning.

For those interested II documented the experience, including some photos, over at AtariAge, Hurricane Beryl.

I recently learned there's new solar inverter that does not require a battery to provide power during an outage: Enphase Energy Launches IQ8, the Industry’s First Microgrid-Forming Microinverter

Unlike competing devices, IQ8 is capable of forming a microgrid during a power outage using only sunlight, providing backup power even without a battery.