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The Newest Capacitors

  1. Jan 3, 2016 #1


    Staff: Mentor

    I'm impressed by the specifications of the newest capacitors. They are sold in the form factor of a D cell battery for at little as $8 each. I have no question. I'm just amazed at how fast that technology is improving. It may be time to consider applications for capacitors that we pooh-poohed before as unrealistic.

    Capacitor versus lead-acid battery
    Energy density 6 Wh/kg versus 33-42 Wh/kg.
    Power density 4600 W/kg versus 180 W/kg.
    Cycles 500000 versus 500.
    Leakage 0.3 mA versus 3-20%/month self-dischargea

    Here are some specs quoted for the capacitors.
    • Brand:MaxWell33-42
    • Rated Voltage:2.7V
    • Rated Capacitance:350F
    • Capacitance Tolerance:0%~10%
    • ESR(DC):3.2mΩ
    • Maximum Continuous Current (at 15℃):35A
    • Maximum Peak Current:220A
    • Maximum Leakage Current (72hrs/mA):0.3mA
    • Power Density (W/kg):4600
    • Maximum Energy (Wh):0.35
    • Energy Density (Wh/kg):5.9
    • Operating Temperature range:-40℃~65℃
    • Storage Temperature range:-40℃~65℃
    • Weight (g):63.3
    • Size (ΦD×L/mm):33.3×61.5
    • Cycle Life:≥500000
  2. jcsd
  3. Jan 3, 2016 #2


    User Avatar
    Science Advisor
    Gold Member

    I too am amazed by the energy that can be packed into such a small package as compared to say 20 years ago. Often times these super capacitors are not suitable for anything except memory backup or something similar due to a high ESR but even that is shrinking down.
  4. Jan 3, 2016 #3


    User Avatar
    Gold Member

    I'm impressed.
    The .0035 ohm esr is calculated after 15 seconds at a 35 amp load. In the "olden days" you couldn't get all the charge at a high current.
    Just for perspective, 350F means 1 amp for 35 seconds drops 0.1v. That's wild!
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