LEAF L2 @ 208VAC - How nuch current?

[Volusiano]

So what you're thinking is that, if I run the voltage down, the LEAF will draw more than 16A even if the EVSE pilot is set to 16A? (I guess I will have to dust off the o'scope to verify Phil did set the pilot duty cycle to 16A.) If this is true, yeah, the LEAF's charger is "broken". Probably won't be noticed, through, because the breaker ratings are normally so conservative because of the "80% rule" that in most voltage sags the breaker would have no problem holding at the increased current.

If the EVSE says that it only has 16A max to give, shouldn't there be come kind of safety feature built into the EVSE itself as well to not allow a "broken" charger to draw more than this max, to have an extra level of safety redundancy built-in?

 

[surfingslovak]

Maybe 4% goes to the charger cooling system?

I like your thinking! I've been looking for more data, particularly spec sheets, but this might explain why we have seen lower than anticipated charger efficiency. Likewise, if only about 3 kW were hitting the battery, it would correlate nicely with 2 bars gained per hour of charging.

 

[tps]

If the EVSE says that it only has 16A max to give, shouldn't there be come kind of safety feature built into the EVSE itself as well to not allow a "broken" charger to draw more than this max, to have an extra level of safety redundancy built-in?

I believe the Coulumb Chargepoints do exactly this, they will shut down if the car draws excessive current; not sure what the overcurrent threshold is, though. For most EVSE's this is probably not necessary. The breaker will trip to protect the wiring if the car draws too much current. The point of the pilot is to tell the car how much it can safely draw without tripping the breaker. I suspect the Coulumb units measure the current and shut down well before the breaker trips, and it will auto-reset to be ready for the next user. This is because a tripped breaker would render a Coulumb Chargepoint inoperative until they dispatched a maintenance person to reset the breaker. On your home EVSE, a tripped breaker is probably very easy to reset, hence they decided not to spend the money to duplicate the safety feature provided by the breaker. Circuit breakers are deemed "safe enough" to protect house wiring with no additional redundancy.