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NPR: EV battery lifespan (good news)

FloridaMan655321

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ClarificationMarch 2, 2026
This story has been updated to clarify that batteries store energy and not power.

Yeah, from the source I can see this happening ;) and I wouldn't be surprised with more clarifications. As for the article, I hope the information is solid, but again the source.....
 

chl

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ClarificationMarch 2, 2026
This story has been updated to clarify that batteries store energy and not power.

Yeah, from the source I can see this happening ;) and I wouldn't be surprised with more clarifications. As for the article, I hope the information is solid, but again the source.....
LOL, one of an engineer's pet peeves, imprecise language in the press.

Power in kW x Time in hrs = Energy in kWhrs which is what the utility charges you for, along with misc. other things like fuel to run their generators, and energy is what batteries store.

Short list of definitions of some units in EE, FWIW:
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Power = energy / time
1 watt = 1 joule / 1 second

So energy = power x time

1 kWhr = 1000 watts x 1 hour
1 kWhr = 3.6 million joules

1 Ampere = 1 coulomb of electric charge moving past a point in 1 second, the unit of electrical current

1 Watt = 1 joule per second (rate of energy transfer) -- A kilowatt (1000 Watts) is a unit of power (rate of flow of energy --Joules-- per unit of time).

1 joule = The work required to move an electric charge of one coulomb through an electrical potential difference of one volt, or one coulomb-volt (C*V): a Joule is a unit of energy

1 joule = The work (energy) required to produce one watt of power for one second, or one watt-second.

1 kWh = 3.6 megajoules (energy delivered by one kilowatt of power for one hour) -- A kilowatt hour is a unit of energy, the product of power and time.

1 volt = the electric potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those points
--the potential difference between two points that will impart one joule of energy per coulomb of charge that passes through it
--the volt is a force, the electromotive force.

1 ohm = the electrical resistance between two points of a conductor when a constant potential difference of one volt (V) applied to these points produces a current of one ampere (A)
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For budding electricians, wire gauges explained:

AWG: American wire gauge -- a logarithmic stepped standardized wire gauge system for the diameters of round, solid, nonferrous, electrically conducting wire -- the cross-sectional area of each gauge is an important factor for determining its current-carrying capacity

No. 36 AWG is 0.005 inches in diameter, and No. 0000 is 0.46 inches in diameter -- The ratio of these diameters is 1:92, and there are 40 gauge sizes from No. 36 to No. 0000, or 39 steps.

AWG rules of thumb:

When the cross-sectional area of a wire is doubled, the AWG will decrease by 3 (E.g. two No. 14 AWG wires have about the same cross-sectional area as a single No. 11 AWG wire.) This doubles the conductance.

When the diameter of a wire is doubled, the AWG will decrease by 6. (E.g. No. 2 AWG is about twice the diameter of No. 8 AWG.) This quadruples the cross-sectional area and the conductance.

A decrease of ten gauge numbers, for example from No. 12 to No. 2, multiplies the area and weight by approximately 10, and reduces the electrical resistance (and increases the conductance) by a factor of approximately 10.

For the same cross section, aluminum wire has a conductivity of approximately 61% of copper, so an aluminum wire has nearly the same resistance as a copper wire smaller by 2 AWG sizes, which has 62.9% of the area.

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For the EV owner:

EVSE = electric vehicle supply equipment, a device that supplies electrical power for recharging plug-in electric vehicles:

AC Level 1: Connects directly to a standard 120 V North American outlet; capable of supplying 6–16 A (0.7–1.92 kilowatts or "kW") depending on the capacity of a dedicated circuit.

AC Level 2: Utilizes 240 V (single phase) or 208 V (three phase) power to supply between 6 and 80 A (1.4–19.2 kW). It provides a significant charging speed increase over AC Level 1 charging.

DC Level 1: Supplies a maximum of 80 kW at 50–1000 V.

DC Level 2: Supplies a maximum of 400 kW at 50–1000 V.

Charge time can be calculated as:
Battery capacity (kWh) / Charging power (kW)

Charge controller/charge regulator/battery regulator: limits the rate at which electric current is added to or drawn from electric batteries to protect against electrical overload, overcharging, and may protect against overvoltage.

Musk: the CEO of Tesla and the world's richest jerk.

SAE J1772 plug: also known as a J plug or Type 1 connector is designed for single phase alternating current electrical systems with 120 VAC or 240 VAC

Combined Charging System combo 1 (CCS1) connector: builds on the J1772 standard adding two additional pins for DC fast charging up to 350 kW

EVSE Signaling protocol: designed for the following charging sequence:
1) supply equipment signals presence of AC input power
2) vehicle detects plug via proximity circuit (thus the vehicle can prevent driving away while connected) and can detect when latch is pressed in preparation for plug removal.
3) Control Pilot (CP) functions begin
3a) supply equipment detects plug-in electric vehicle (PEV)
3b) supply equipment indicates to PEV readiness to supply current
3c) PEV ventilation requirements are determined
3d) supply equipment current capacity provided to PEV
4) PEV commands energy flow
5) PEV and supply equipment continuously monitor continuity of safety ground
6) charge continues as determined by PEV
7) charge may be interrupted by disconnecting the plug from the vehicle
 

chl

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