Top Tips for Optimal Battery Health

[WannabeOwner]

Frequent Supercharging can decrease charge rates

Does this mean charging the battery at slower rates (if your car usage allows this) is better for longer term battery health?

Yes. Frequent Rapid D/C charging stresses the battery, such that after a certain number of D/C charges the D/C charge rate will progressively reduce over time. It isn't a dramatic reduction, but it is intended to avoid battery decline that continued rapid charges would cause.

By my rough maths, on a Model-S, rapid D/C charging 10% of the time will start to reduce D/C charging speed at around 80-100K miles.

Why the need to constantly trickle feed juice from the grid and keep it topped up at 80 or 90%?

It isn't a trickle feed (that I know of), but rather once the battery SOC falls X% then it tops it back up again to LIMIT (during the schedule charging period, if set)

Why would you not keep the car plugged in when not using it for a few weeks?

Cars have been know to lose range. You might leave Sentry mode on (which consumes power), or you might want to! There have been instances where cars lost range when parked for no apparent reason. My M3 did when parked for a week, no idea why, hasn't happened since, sentry mode etc. was off. My supposition is that it was very hot during that week and maybe HVAC came on

Flip side: I would prefer my car was not plugged in if Thunderstorm likely.

I've been reading this forum for 4 years or so. There have been plenty of stories of high mileage vehicles (airport taxis and the like) which were rapid charged often, left sitting charged to 100% for hours, and so on, but still only lost 7% or so at 100-200K miles.

Also stories of batteries that were replaced under warranty (Bjorn had a new battery on his MX, although his was a very early model ...)

My car is 3.5 years old and coming up to 100K miles, Supercharged 10% of its miles, and has lost about 7% range; it has a 90 battery which anecdotally is the least-good chemistry.

Stories that I have read of 100K Model-3 (there aren't many ...yet) have even less degradation

I haven't seen anything that makes me feel the need to adopt a cautious approach to looking after the battery.

My house-rules are:

Normally charge to 90% (can't see any benefit in 80%, except having less range on the days when i unexpectedly need it)

If charging to 100%, before a longer journey, do so shortly before departure. And try to allow enough time that it finishes (so that the cells get balanced)

If arrive below 20% then charge immediately (up to 40-50% at least) so the car doesn't sit at low SOC (e.g. until next scheduled charging at Off Peak)

If I was going to leave the car for a prolonged period I would plug-in and set the LIMIT to 50%

 

[Roy W.]

This is quite interesting, about a US Model 3 that has covered 100,000 miles, with very little battery degradation. Perhaps we’re being a bit over-cautious with our various battery regimes!

Tesla owner becomes first to push Model 3 to 100,000 miles, here's how it's doing - Electrek

 

[elecTED]

I’ve never put my cars in the garage before in 16+ years of having quite easy access to oversized garages in the two houses we’ve lived in. (Garages are for junk, not cars is kinda my philosophy)

I’m thinking for the M3 there may be good reasons to clear some garage clutter and use it, especially in winter.

Apart from helping to keep a new car cleaner for longer what would the benefits be in terms of battery health?

Will I be using less electricity to charge the car over the winter months if the car is kept warmer overnight in the garage?

 

[WannabeOwner]

what would the benefits be in terms of battery health?

I doubt anything ... in a colder climate then "maybe", but as I understand it Car will Heat the battery, before charging it, if the battery is very cold, so I am doubting at UK temperatures it would make much difference.

Will I be using less electricity to charge the car over the winter months if the car is kept warmer overnight in the garage?

I reckon that use of battery heater will be less, and perhaps less transmission-losses, so I reckon it would save some money ... Could ask Bjorn to compare charging his in his garage ... and outside

Also less energy to heat cabin during pre-conditioning before departure?

 

[Roy W.]

I’ve never put my cars in the garage before in 16+ years of having quite easy access to oversized garages in the two houses we’ve lived in. (Garages are for junk, not cars is kinda my philosophy)

I’m thinking for the M3 there may be good reasons to clear some garage clutter and use it, especially in winter.

Apart from helping to keep a new car cleaner for longer what would the benefits be in terms of battery health?

Will I be using less electricity to charge the car over the winter months if the car is kept warmer overnight in the garage?

If you keep the car in the garage in winter the battery will start off a few degrees warmer.

Also you won’t need to precondition the car in the depths of winter to melt any frost or snow.