Any longer terms consequences to battery life charing at 120v?

[MarkoJ]

I've had the Tesla for a week and I've been using the NEMA 5-20 in my garage at 8 km/hour and the car is charged every morning. I am thinking about getting a NEMA 14-50 but other than charging efficiency from a cost perspective is it any worse for the battery life/expectancy to charge at 120v for years on end?

 

[Ames]

I'll let the real experts chime in here, but I personally can't imagine how it would do any long term damage given that the whole system will be stressed by far less heat than if you were charging at higher power. If you think it's bad for the car, take it to the supercharger once in a while to balance things out.

 

[MarkoJ]

Only reason I ask is everywhere I look the NEMA 14-50 seems to be the only acceptable form of charging so just want to make sure I am not missing something charging with 5-20 as the range I get overnight is sufficient.

 

[mikeash]

My understanding is that charging faster is what hurts batteries, not slower. Even then, no AC charging gets anywhere near fast enough to be problematic, and even Supercharging seems to be fine in that respect. 120V charging should be fine for your battery. The only downsides are the inefficiency and the slowness. If you're OK with both of those then carry on!

 

[ChadS]

In theory, it should be fine for the car. The major drawbacks to charging at 120V are lower efficiency, the extra time it takes, and your utility likely wishing you were charging off-peak rather than plugging in as soon as you get home (if you have TOU rates this might mean a financial difference for you).

Oh - you should also note that in extreme weather conditions, the 120V power may all be diverted to pack temperature management, so you might not really get a charge. But you are talking about in a garage where that is unlikely to happen.

In practice, I think it's usually fine for the car too. There are other Tesla owners that charge at 120V; most Volt owners do; and the last time I saw the numbers even close to half of LEAF owners do. The only caveat I have is that Tesla once told me that long-term 120V charging could throw off capacity calculations on my Roadster. I got the impression that only applied to the Roadster, though.

 

[FlasherZ]

You shouldn't have any problems. 120V charging is slightly less efficient, as reflected in Tesla's calculators, but that really doesn't have any bearing on battery longevity. In some cases it may be better to go with the higher voltage -- say, charging at 120V for 4 hours in 130 degree heat might be worse than charging at 240V for 2 hours in the same hear. However, given Tesla's thermal management in the pack, I don't think you'll have to worry about that (and at that low rate of charge, I don't see an issue anyway).

My approach: I charge at 80 & 72 amps every day, plug it in the moment I get home. I just don't worry about it - and you shouldn't either.

 

[Iz]

Have been charging my MS 60 on 120V for 3 years now. During the summer months the family takes trips and we use superchargers or the NEMA 14-50 plug at campgrounds. Have not range charged in over 7 months; but am quite certain the 60 kWh battery will still top off at or near 200 miles.

 

[byan1232]

My DS told me to do a charge with 120V outlet once in a while to balance the battery. It actually extends the life of the battery therefore constantly charging at 120V is actually ideal, but not cost effective or efficient.

 

[stopcrazypp]

You shouldn't have any problems. 120V charging is slightly less efficient, as reflected in Tesla's calculators, but that really doesn't have any bearing on battery longevity. In some cases it may be better to go with the higher voltage -- say, charging at 120V for 4 hours in 130 degree heat might be worse than charging at 240V for 2 hours in the same hear.

It may seem counter-intuitive, but I wanted to point the same thing out. On paper 120V should be more mild on the battery (less resistive losses and lower C-rate), but if you factor in that it extends the amount of time your car is charging, it may actually be worse for the battery. However, the differences are so minor that it's not worth stressing over.

The biggest negative remains the lower efficiency and long charge time.

 

[jerry33]

Battery balancing begins at 92 or 93% and then continues over several days regardless of charge level. Slower charging is easier on the battery, but any home charging is already very low. Even an SC charge is only 1.5C for a short period of time.