Why? Flexibility, fast charging, adjusting to what space is available, a
backup encase a charger fails, +more ...
Others can speak of their reasons, but mine were of that point in time
(the old-days when there wasn't a 6kW j1772 level-2 EVSE around every
corner). Some times, I had access to two 120VAC 20A level-1 outlets, or
two 208VAC 20A , or two 240VAC 30A dryer level-2 outlets. And if I did
have access to a 14-50 or a 50A oven or dryer level-2 outlet, I would
run both chargers off that outlet.
Of my six chargers, I had a mix and match of different AC voltage input
types and charger capacity abilities. These got switched around over
time to match what was available out in the public. Initially, I had
access plenty of level-1 outlets at a site (each on their own 20A
breaker) to plug into. So, initially I had four level-1 chargers, and
two ~3kW level-2 chargers. Later, as more level-2 power was available, I
changed my charger configuration to a two level-1 and four level-2
charger setup (two ~3kW, and two ~6kW).
I needed to do this, because when I went exploring long distances, where
ever I landed, I wanted the most flexibility to get a charge. That
design had paid off, again and again. Perhaps the most 'fun' I had was
when I was at one of the nedra.com EVents in Las Vegas, NV and the local
EAA Chapter had arranged to provide a huge genset. I had enough power
available I was able to plugin all my chargers at the same time and get
the fastest charging I had ever done. Sweet!
...
[dream-mode-on
Let's say I had a conversion that fit the big-n-tall body God gave me,
that had a ~300 mile li-ion pack. I would likely want to have a similar
setup as Al mentioned but with 6kW capabilities. One charger would allow
me to dial in what I want (i.e.: a pfc-50, from a low level-1 up to a
high level-2). The others would be isolated 6kW chargers. All chargers
would be fed from multiple j1772 ports in the front of the vehicle. And
I would carry on long trips extension cables to reach nearby level-2
EVSE.
Lets assume a gen1 Leaf EV's pack is 100 miles (when driven by an EV
driver) and it charges to 80%SOC (state-of-charge) in 8 hours using its
3kW on-board charger. If I came in to a typical public EVSE with a j1772
6kW ability, to recharge my 300 mile pack would take 3 times as long (24
hours - Sheesh, that is like recharging a Leaf EV at level-1). I could
plug in to four public j1772 6kW EVSE and knock that recharge to 80%SOC
time to ~3 hours. Those numbers are all guesstimates but I think you get
my point: short of working out to have a level-3 charging ability on
that EV, using multiple level-2 6kW on-board chargers gives charging
flexibility.
How would I use this other than on logn distance driving. What if I was
given a work task that wanted me to drive far away, and I went I came
into work I was not charged enough to leave. I would add to the one 6kW
j1772 connection, three more, and zoom up to the SOC quickly. Thus
letting me be quickly on my way.
/dream-mode-off]
If the Tesla-S' level-3 charging was CHAdeMO compatible, instead of
having the 300 mile range conversion above, I could just pour that same
money into a Tesla-S with a ~300 mile range pack (better resale value).
{brucedp.150m.com}
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On Fri, Mar 22, 2013, at 04:59 PM, Ds2inc wrote:
> What's the advantage of chargers in parallel?? Faster charging?? Less
> stress on the traction pack?? I understand it from a versatility position
> ( I.e. 110/220/ j1772) but do get the reason for running then at the same
> time??
>
> Still learning!!!
> Stephen
-
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