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What size CB Panel?

Discussion in 'Model S: Battery & Charging' started by Piney999, Jan 28, 2017.

  1. Piney999

    Piney999 Member

    Feb 27, 2016
    North of Spokane Washington, Earth
    A quick question for those who have two electric cars.... What size CB Panel are you guys working with. I am Currently a one car family, but will soon be a two car family, and I am trying to decide how big to go on the CB panel. Any thoughts would be appreciate!!
  2. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

    Mar 8, 2012
    It's a lot like disk space--there's almost no such thing as too much. Mostly you're paying for the installation because the difference in cost in the various panel sizes is not all that much. FWIW, I have a 200 amp panel and a 100 amp subpanel. The four big loads are 14-50 for the Tesla, Clipper Creek for the Leaf, 6 KVA UPS, and A/C. 1800 sq.ft. house.

    If you are putting in a couple of HPWCs, then 400 or 600 would be a better choice.
  3. GSP

    GSP Member

    Dec 28, 2007
    How much electric service you need will depend on how much daily driving your household does.

    If you drive less than 60-80 miles per day in each car, then as little as 20 amps service per car (16 amp charging) will be enough.

    If you drive more, you may need 30 amp service for each car (24 amp charging).

    50 amp service per car (40 amp charging) can handle any overnight charging need.

    If you need a fast daytime top up for your car or a visitor's car, then go as big as you can, up to 90-100 amps (72-80 amp charging, the max Telsa cars can use).

    Tesla's new HPWC can share load between two or more cars. This is the hot setup for multi-EV households. I would go with a 60 amp circuit to feed both cars. Each car needs its own HPWC, and can use the entire 60 amps (48 amp charging) when the other car is not charging. That is good for quicker top ups. When both cars are charging the load is split between them.

    How big a panel you need will also be determined by your household loads. Do you have any gas appliances? If so a 200 amp panel can supply a 60 amp EV charging circuit in most homes. For large or all electric homes you may need more. Consult a local electrician.

    Good Luck,


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