# Forums

## Tesla home charger and max Amp charging output

I have a Tesla model 3 mid range with 260 mileage.
The car can charge more than 50amp at Tesla charger at Tesla location. However at home, I cannot get it over 32amp. The amp charge increase + button comes grayed out.

Electrician has already set the calibration to 48, breaker is 60amp rating and cable has 60 amp rating too. Yet I am getting only 32amp max.
Any suggestions if model 3 is capable of charging more than 32amp at home wall charger? The voltage rating is 240volt.
Thanks
Jitendra

Lonestar10_1999 | September 13, 2019

The mid range model is limited to 32 amps charging rate when plugged into a 240vac power source. The same is true for standard range. The long range however has the premium charging rate of 40 amps.

These limitations are imposed by the cars onboard ac/dc converter. Since super charging uses a dc power source, the ac/dc converter is bypassed and does not limit the charging.

Tronguy | September 13, 2019

@Jitrendra,
Sure wish we had sticky threads around here. So, in order:
1. The conversion between AC city power and DC battery power is in the car, not in any external equipment.
2. The SR/SR+ has (a) a smaller battery and (b) a smaller AC/DC converter inside the car than the LR and up cars.
3. The maximum that the SR/SR+ can charge at 250 VAC is 32A. Sorry if you got some information somewhere that said otherwise, but that is the case. Here's the link: https://www.tesla.com/support/home-charging-installation/onboard-charger. Note that the power for the SR/SR+ is 250V*32A = 8 kW. Those of us with LR and better have an on-board charger that can do 48A, so we get 250V*48A = 12 kW.
4. If you are at a Supercharger, the internal "charger = AC to DC converter" is bypassed and DC is passed more directly to the battery pack. Under these circumstances, the battery can be charged at rates (depending upon the Supercharger and where you park) of 64 kW up to (!) 250 kW, although the most common, highway-style Supercharger is at 120 or 150 kW these days. When Supercharging, the cars hit that peak power only for a short while at about 30% to 50% of battery full charge; after that, the car slows down the charge rate to keep the batteries from being damaged. I suspect that the "50A" you saw was actually "50 kW", which is typical for a car nearing full charge.

Finally: Sorry to tell you this, but you may have overspent a bit on that \$500 TWC (That's the Tesla Wall Connector) box. The charging cable that comes with all the M3's has a max charging rate of 32A at 250V. If one has a LR M3, which can actually do 48A, a TWC helps by being able to do 48A. But, since you've clearly got an SR car, you're not going to get that 48A, which is a function of the car, not the TWC. You would have gotten the 32A from the mobile connector in the trunk anyway.
On the other hand, the TWC is certainly more convenient that the mobile connector, so it's not money totally wasted.

Hope this all helps.