# GE WattStation EV chargers for sale on Amazon



## tomofreno (Mar 3, 2009)

I was told by Coda that one of these is required for charging their car. Gee, only $1k to be able to plug it in. Why is it that the Tesla roadster does not require an EVSE but all ev's from major auto manufacturers do? And why do they call them "chargers", when the charger is on-board? It seems that all the intelligence that is in the EVSE could easily be built into the charger, but I don't see why it is necessary other than a revenue generator.


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## palmer_md (Jul 22, 2011)

The main reason is safety. By using the EVSE, the cord is "dead" until it is connected to the car and then becomes "live".

Secondary reason is to be able to communicate to the cars on-board charger the maximum available current from the source. This allows large on-board chargers to automatically throttle current draw to match the breaker trip rating on small charge stations. (eg. the onboard 10kW charger (40amp) won't trip a breaker from a charge source with a 3kW (15amp) supply).

edit: Tesla does require an EVSE. They come with the ClipperCreek unit (I think).


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