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Watt-hour per kilogram

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(Redirected from W⋅h/kg)
watt-hour per kilogram
Unit systemUnit accepted for use with SI
Unit ofSpecific energy
SymbolW⋅h/kg
Conversions
1 W⋅h/kg in ...... is equal to ...
   SI units   3600 J/kg

The watt-hour per kilogram (SI symbol: W⋅h/kg) is a unit of specific energy commonly used to measure the density of energy in batteries and capacitors.

SI Units

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In the SI system of measurement, one watt-hour per kilogram is equal to 3600 joules per kilogram.

Typical values

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The batteries that Tesla uses in their electric cars deliver about 254 W⋅h/kg,[1] compared to supercapacitors that are typically rated between 3 and 10 W⋅h/kg,[2] with the best commercially available supercapacitors as high as 47 W⋅h/kg.[3]

Nuclear batteries based on betavoltaics can reach up to 3300 W⋅h/kg, although over much longer time periods.[4]

References

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  1. ^ "Tesla’s batteries have reached their limit – here’s how they could go further", theconversation.com, 2017-11-16
  2. ^ Hao Y, Santhakumar K (2013). "Achieving Both High Power and Energy Density in Electrochemical Supercapacitors with Nanoporous Graphene Materials": 3. arXiv:1311.1413. Bibcode:2013arXiv1311.1413Y. {{cite journal}}: Cite journal requires |journal= (help)
  3. ^ Ronald Brakels, "Arvio Supercapacitor Energy Storage — Powerful Enough To Beat Batteries At Their Own Game?", Solarquotes.com, May 15, 2018. Retrieved 14 Oct. 2021
  4. ^ Prototype Nuclear Battery, phys.org, June 6 2018