A 240-volt EVSE is something most EV owners choose to install. If you
want to plug into 120-volt “house” current with the included cord, plan
on it taking around a day and a night or longer to recharge a depleted
battery.
EVSE units are basically a fancy switch with safety built in to
prevent unfortunate things like you electrocuting yourself, or taking or
delivering more power than would be copacetic.
They plug with a special
multi-pin connector into the car – usually an SAE J1772, but Tesla (like Apple) which likes to
zig when everyone else
zags – has gone its own route with a proprietary plug and port, but offers adapters.
The EVSEs sold today vary in their maximum amperage and kilowatt output and thus can serve as another effective bottleneck.
Manufacturers typically quote level 2 recharge times based on the
assumption that you are using the most potent 240-volt EVSE possible,
often 30 amps with kilowatts varying.
If an EV can take more amps or kilowatts, that means it can replenish more “miles of range per hour” as Tesla puts it.
These details are not always spelled out in graphic detail by EV
sellers, but the good news is it is not advanced astrophysics. When we
asked every EV maker in America today to answer the same list of
questions, we got varying degrees of transparency. Some did not know all
the answers, some failed to even get back to us, and Fiat (Chrysler)
took the cake as being the most crystal clear in its answers to the
spirit of what we were asking.
“Amperes are everything when it comes to recharging. Charge time is
directly proportional to amps,” replied Chrysler media rep Jiyan Cadiz.
“A simple example would be, if you install the AeroVironment Level 2
EVSE (30 amp service) offered through Mopar on a 20 amp circuit, the
charge time would be 1/3 slower (or 20 amps/30 amps = 2/3 max energy
draw into the car).”
And we’ll add, if you buy a 15 or 25 amp EVSE and plug in a car set
up for 30 amps or more, you have again effectively handicapped your
recharge time.
On the other hand if your car can only accept 30 amps, and you plug
in a 40-amp EVSE, software will limit the input, and it will charge no
faster than at 30 amps.
We could go on and on adding qualifiers to this, but the simple
answer is if you want fastest recharge times, the correct thing to do is
to ask the automaker or a charging equipment supplier what’s the
fastest way to go.
Among EVSEs, Tesla offers the most potent – its High Power Wall Connector (HPWC) – with up to 80 amps deliverable to cars with “twin chargers.”
This, by the way, is the answer to how Tesla at “level 2” can charge a
Model S quicker than a Mitsubishi i-MiEV. The Tesla also costs around
four times more, so go figure.
Tesla advertises that 62 miles range per hour gets added back to a
Model S using its HPWC under ideal conditions of voltage, amperage and
wire gauge size at minimal length. We know of one Model S Signature
Performance owner who uses all 80 amps of his HPWC plugged into a
dedicated 100-amp circuit, and gets only 54 miles per hour range.
Quicker Options
Beyond home charging, a few cars accept what’s called “level 3” or
“DC Quick” charging. These expensive-to-install public EVSE deliver
around 480 volts and a whole lot of amps. Tesla also has its public free
“superchargers.”
Final Note
If you plan to install a charger at home – for any brand EV – you
will want to ensure the amperage of the line is up to the needs of the
charging equipment, and ideally, use a “dedicated circuit.”
In other words, do not also run an air conditioner or clothes dryer
on the same circuit, or this will limit the power to your car, and may
even overload the circuit if it is not set up for this much draw.
see here :EV Recharge Times
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