Sizing subpanel for future connections

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Newbie here, hello all!

I've got a home with the garage on the opposite side of the house from the 100A main circuit breaker. The first step is to upgrade the main to a 225A panel, and I'm planning on adding a subpanel in the garage to support future EV chargers/battery storage/etc. Does the 120% rule apply to the subpanel in the same way it applies to the main?

For example if I installed two 30A battery storage devices in a 125A subpanel, would I need to downsize the breaker feeding the subpanel to be 90A? (125*1.2 = 150 - 30 - 30 = 90)

I worry that doing so may limit me when putting in two 50A chargers. So perhaps I should just install a 200A subpanel so I don't have to worry about it?


Staff member
Durango, CO, 10 h 20 min without traffic from wing
wire pulling grunt
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