* I'll preface this with stating my understanding that this is a largely academic discussion, and that no matter what charging strategy employed, battery degradation won't matter overly much across the 5 or so years I plan to own this car. I also have a MX75D but there are more people in the MS forum and it's the same battery type, so who cares?
I'm a fairly heavy driver (though probably a lightweight with some around here) at 15k miles a year, but I work from home, and live in a big city where I spend most days walking or taking transit when I'm not traveling.
So my driving goes something like this:
Dahn states that discharging and charging can shorten the lifespan of a battery, but that the 30->70 is x-numbers less harmful than the 0->100. He also states that slow trickles of discharge are the best for the battery (so letting it vampire drain is better for the battery than driving the car, for example). And of course, he doesn't recommend charging beyond 70% if you don't need it, though we have some conflicting information here primarily around the TM3 battery and its issues with calibration unless you regularly charge to 80% or 90% (I don't have a TM3, so doesn't apply here). Dahn's advice isn't always based on the batter the Tesla MX and MS has, so it's always a little confusing as to what applies to us.
So using all that logic, my best practice is to let the battery naturally trickle down without any evening top-offs to bellow 50% (some would argue to bring it down to 30%, which makes sense I guess, but I'd like some mileage on the car in case of any unexpected driving). Once below 50%, charge it to 80%, and let it trickle down again.
I also realized, that instead of charging at midnight during the winter, it's probably best to charge the car immediately when coming home because the battery is already conditioned. If you charge at midnight, you're losing heat, wasting energy heating up the battery, before charging up. You're better off charging to (let's say) 70% from when you get home, and top it off to 80% an hour before you drive to head out with a warmer battery. I live in Canada, but my garage is fairly warm, so this isn't such a big issue for me.
So my strategy thus far has been, have a charged car by Saturday morning when I do most of my driving on the weekend, and let it trickle down to below 50% due to vampire drain (it usually doesn't get that low over the week anyway), and recharge again to 80%.
Am I missing anything? I'd love to hear your comments for those that obsess about these details.
* Also, I'll add the obvious, that the car is always plugged in! And I'm charging, not charing...
I'm a fairly heavy driver (though probably a lightweight with some around here) at 15k miles a year, but I work from home, and live in a big city where I spend most days walking or taking transit when I'm not traveling.
So my driving goes something like this:
- Monday to Friday, almost no driving, or at most a few short occasional <10 mile drives
- Saturday and Sunday can reach 30 to 50 miles with errands, being out with family, friends, etc..
- Occasional I take planned in advance longer drives or road trips <- This part is the easy part, charge to 90% or 100% if you need it the night before, and done.
Dahn states that discharging and charging can shorten the lifespan of a battery, but that the 30->70 is x-numbers less harmful than the 0->100. He also states that slow trickles of discharge are the best for the battery (so letting it vampire drain is better for the battery than driving the car, for example). And of course, he doesn't recommend charging beyond 70% if you don't need it, though we have some conflicting information here primarily around the TM3 battery and its issues with calibration unless you regularly charge to 80% or 90% (I don't have a TM3, so doesn't apply here). Dahn's advice isn't always based on the batter the Tesla MX and MS has, so it's always a little confusing as to what applies to us.
So using all that logic, my best practice is to let the battery naturally trickle down without any evening top-offs to bellow 50% (some would argue to bring it down to 30%, which makes sense I guess, but I'd like some mileage on the car in case of any unexpected driving). Once below 50%, charge it to 80%, and let it trickle down again.
I also realized, that instead of charging at midnight during the winter, it's probably best to charge the car immediately when coming home because the battery is already conditioned. If you charge at midnight, you're losing heat, wasting energy heating up the battery, before charging up. You're better off charging to (let's say) 70% from when you get home, and top it off to 80% an hour before you drive to head out with a warmer battery. I live in Canada, but my garage is fairly warm, so this isn't such a big issue for me.
So my strategy thus far has been, have a charged car by Saturday morning when I do most of my driving on the weekend, and let it trickle down to below 50% due to vampire drain (it usually doesn't get that low over the week anyway), and recharge again to 80%.
Am I missing anything? I'd love to hear your comments for those that obsess about these details.
* Also, I'll add the obvious, that the car is always plugged in! And I'm charging, not charing...
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