Calculate the charging time for my Electric Vehicle

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Discussion Overview

The discussion focuses on estimating the charging time for electric vehicle batteries, considering factors such as battery capacity in kWh and charging power in watts. Participants explore the impact of charging efficiency and the trade-offs between charging speed and battery longevity.

Discussion Character

  • Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant proposes a basic formula for estimating charging time as Capacity / Charge effect, using an example of 100kWh and 9600W to suggest a charging time of 10.4 hours.
  • Another participant suggests adding about 20% to the required charging amount to account for inefficiencies, noting that faster charging rates can reduce efficiency and affect battery lifespan.
  • A question arises about whether to add the 20% to the charging time or the charging effect, with some arguing that it could be interpreted either way.
  • A later reply emphasizes that in practical scenarios, if battery longevity is a priority, one should add to the time, while if impatience is a factor, one might add to the charging effect.
  • One participant calculates that adding 20% to the initial 10.4 hours results in approximately 12 hours for a full charge.

Areas of Agreement / Disagreement

Participants express differing views on how to account for inefficiencies in charging time estimates, with no consensus on whether to add the 20% to time or effect. The discussion remains unresolved regarding the best approach to incorporate these factors.

Contextual Notes

The discussion highlights the complexity of estimating charging times due to various assumptions about efficiency and the impact of charging rates on battery health, which remain unresolved.

Lobotomy
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So cars usually specify the batteries in kWh (rather than Ah).

So given that i know the kWh capacity of a car.

I also know the charging effect in W (i.e. the voltage and amps in my charging station).

Can I reasonably estimate the time it'll take to charge the battery? It doesn't have to be super accurate.Is it as easy as

Capacity / Charge effect = time i.e.100kWh / 9600 W = 10,4 hours to charge?

And assuming i have 5 hours to charge that'll reguire 100kWh/5= 20 000W if i want to be able to charge it full in that time.
 
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To account for various inefficiencies, especially of the batteries, add about 20% to the amount needed for full charge. The faster the charge rate the less efficient it is. Also the faster the charge rate the sooner the batteries will need replacement due to loss of capacity.
 
Tom.G said:
To account for various inefficiencies, especially of the batteries, add about 20% to the amount needed for full charge. The faster the charge rate the less efficient it is. Also the faster the charge rate the sooner the batteries will need replacement due to loss of capacity.

add 20% to time or effect?
 
Lobotomy said:
add 20% to time or effect?
Isn't it saying the same thing either way?

In the "Real World", add to the the time if longer battery lifetime is important to you. If you are impatient, add it to effect.

It's just a case of batteries not being 100% efficient.
 
100kWh / 9600 W = 10,4 hours
10.4 hours plus 20% = About 12 hours.
 

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