1. Junior Member
Join Date
Jun 2012
Location
dyersburg, tn. usa
Posts
2

## battery charging calculation

are there any methods for calculating multiple battery charging stations in a large industrial plant? ie (4) 600 volt 3 phase 3 wire panels specifically for battery charger stations.

2. Senior Member
Join Date
May 2008
Location
London, England
Posts
643
What do you wish to calculate ?
Circuit ampacity of each branch circuit ?
Feeder ampacity for a number of battery chargers ?

For each branch circuit, I would follow the suppliers instructions, after making some simplified calculations in case there is a typo or mistake in these instructions.

For a feeder that suppliers a number of battery chargers, I would simply add up the actual input of each battery charger.
If the chargers are relatively slow chargers and therefore likely to run for more than 3 hours, then upsize to 125% for the continous load.
If they are fast chargers and complete the chargeing cycle in less than 3 hours, then a simple total should be sufficient.

If the current input is very variable, then it MIGHT be resonable to allow a smaller feeder ampacity on the grounds that not all the chargers will use the maximum at the same time.
For charging a company fleet of EVs, it is likely that at the end of the work day all chargers will be in use at the same time, at full capacity.

For charging a number of privatly owned EVs in say a parking lot, it is unlikely that all chargers will demand full power at the same time.
Some chargers may be unused, or connected to vehicles that are nearly charged.

3. Junior Member
Join Date
Jun 2012
Location
dyersburg, tn. usa
Posts
2

## battery charger calculations

The actual question is in a design build process the customer wants (4) battery charging areas in a large industrial facility with a 600 amp panel for each. The fork lifts and equipment will be recharged at different intervals at each location. So for the plant service size do you have to calculate the total loads for these areas as if every charger is running at the same time or is there a demand factor that can be used per NEC?