How Many Amps at 120V

We have two metrics that indicate the Prime charger may be briefly cycling ON/OFF during the charging:




Two hypothesis come to mind:

• checking the unloaded battery pack voltage
• thermal, the charger gets too hot and has to cool

The first one, no problem although it is a little kludgie. The second one would cause me concern as that means trouble in the Alabama summer heat. Anyone have some insights?

Bob Wilson

 

I would guess this is battery pack checking of one sort or another. It definitely isn't cooling as it's off for too short a time.

 

It does look like a 15 minute interval.

Bob Wilson

 

The PIP had the same results

 

if it was a fifteen minute interval then 15 minutes times 16 intervals equals an extra 4 hours to the charging interval so it's highly unlikely that it's 15 minutes.update: oops ok, you mean every fifteen minutes, that makes more sense

 

Good plan on the 30 amp sub panel.

Utilities are concerned about wave form pollution back feeding into their system. Harmonics from utility customers are reflected onto the utility grid and accumulate as customers add more modern electronics, like the non-linear loads from charging stations. Because harmonics can result in higher maintenance costs to the utility, financial penalties for lack of compliance with a utility's harmonic limits are very common for industrial and commercial customers. These penalties are significant, and therefore most commercial and industrial customers install equipment to condition the back feeding of such anomalies into the grid. I doubt such measures are present in electric car chargers, but given a significant installation base, they may be necessary or customers may face penalties for violations.