Charging Approach

[breckmorrison]

I picked up my MX 75D a couple of weeks ago and trying to understand best practices for charging the battery. I am able to charge at work for free 4 hrs per day and do not have a charger at home because my condo building wants to charge me $150/mth for a stall with ability for charging. RIP OFF!

1) I have heard it is best to set the battery max to 70% instead of 90%. Is that accurate? It looks like the new feature shows "day trips - 70%" and "road trips - 90%" or something to that effect.
2) Is it best to charge a little everyday and keep it at the max level or wait until it gets a little lower and charge less frequently, but for longer duration? This would put me at charging about once a week.

 

[ModlS3XY]

Keep the battery charged is what I’ve heard. 70 or 80 is the recommended max for daily use.

 

[animorph]

The standard is charge to 90% max for normal use. 100% is OK when driving immediately after. Try to stay above 10%. Keep it plugged in whenever possible.

In general, it should be best to operate around 50% with small charges as needed. So 70% to 80% max should be better than 90%, and taking it down to 30% should be better than 10%. But I haven't seen any supporting data for that, just generic lithium battery data.

 

[ahirbe]

I have a charger at home, but try not to use it...mostly because I am cheap, but also because I live 5 mi from a supercharger. I drive 70-80 miles everyday and charge at the supercharger every other. My range does take a hit on cold days but I have been working with some custom HVAC settings and thicker socks . I always charge to 90% otherwise I'd be charging everyday.

 

[mxnym]

I have a charger at home, but try not to use it...mostly because I am cheap, but also because I live 5 mi from a supercharger. I drive 70-80 miles everyday and charge at the supercharger every other. My range does take a hit on cold days but I have been working with some custom HVAC settings and thicker socks . I always charge to 90% otherwise I'd be charging everyday.

Pretty sure the DC fast charge is harder on the battery. Also pretty sure that I saw something somewhere about someone hitting a DC fast charge limit and being limited to a much lower rate at superchargers to protect the battery. If you intend to keep the vehicle for a long time or might road trip at some point, I wouldn't recommend using the supercharger as a regular charger when you don't need to.

 

[TexasEV]

Doesn’t anyone RTFM any more? You don’t need to wonder if it’s better to charge every day or just plug in when the charge gets low. The answer is in the owners manual IN UPPER CASE. Hint— read the battery section.

 

[Rocky_H]

Aside from @TexasEV 's good advice, there's a lot of flexibility there. There is maybe a barely perceptible difference between what is "ideal" versus what is "fine". As @animorph mentioned, ideal best case for longevity of most lithium ion battery types likes being kept near midrange state of charge. So if you find that you're only running about 20 percent off your charge each day, and so you're going between 70 and 90% all the time, yeah, you probably don't need to keep it that high and could probably turn the limit down some to 70 or 80% to be just a little bit healthier for the battery. I keep mine at 80% because we don't drive a lot, and that's still just a little over 200 rated miles, which is plenty for any of our days around town.

Sitting near 0% or 100% for long periods of time is what is bad for them, and I think there has been enough data showing that 90% is far enough away from full to not have much negative effect, so if you need a lot of range frequently, sure, go ahead and keep it near 90%.