A question about how to protect a battery of an electric car?

  • Thread starter hagopbul
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Hello all:

I have a question about electric car battery ?

What is the best charging method for the battery ?

Is it high ampere charging or high voltage charging ?
Thanks in advance
H
 

berkeman

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What is the best charging method for the battery ?
The best way is to use the built-in charger in the Electric Vehicle. There are many different battery chemistries and configurations:


Are you wanting to make your own custom charger? Why? And what is your previous experience in designing battery chargers?
 

sophiecentaur

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And what is your previous experience in designing battery chargers / bombs?
The car manufacturer is the best person to be making chargers for your HIGH POWER FAST CHARGE FAST DISCHARGE car battery. Steer well clear unless this is just a thought experiment.
 
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dlgoff

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Last edited:
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My question is scientific actually :
I entered an argument that if we use high voltage that is less damaging for a battery than using high ampere

Currently battery technology is under development around the world for electric cars but long time charging are just making things hard for electric cars to sweep the market

I noticed that when ads talking about new electric cars they mention 800 v or 200kva for what they called fast or super charging technology .

So back to the question
Dose high ampere charging is better for a battery or high voltage ?
 

sophiecentaur

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So back to the question
Dose high ampere charging is better for a battery or high voltage ?
There is no definitive answer to this - even when a particular technology is specified. Even with the humble Lead Acid Battery, there are are a number of different designs that are used in different applications and require different charging for optimum performance.
Have you read the Battery University, as recommended?
 

berkeman

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Dose high ampere charging is better for a battery or high voltage ?
I don't think that is a well-formed question. Please give a link to what you read with that vague statment:
if we use high voltage that is less damaging for a battery than using high ampere
And please do some reading about bettery charging for the different battery chemistries. There are optimum charging profiles for each chemistry, and deviating from those profiles can shorten battery life (and shorten your life if you are standing next to a battery that you try to charge too fast).
 

russ_watters

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You can also google for different charging profiles.

As worded though, the question makes no sense because voltage and current are tied together. You can't pick between "high" voltage or current, if you pick one, you get the other!
 

Baluncore

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The battery voltage and battery charger output voltage will be regulated which sets the charger output voltage. The rate of charge is then proportional to the curent available from the charger. But what voltage and current are needed to supply the charger?

An EV with 100 kW rated power is designed to transfer energy from the battery to the motor at a rate of 100 k joule per second. If we recharge it at that same rate as discharge then we need a 100 kW battery charging power supply. A typical house outlet is only rated at 2.5 kW, so it will need a special supply. There are many possible combinations of voltage and current that will supply 100 kW. Some are; 250 V @ 400 A, 500 V @ 200 A, 1 kV @ 100 A, 2 kV @ 50 A and 4 kV @ 25 A. Obviously the higher currents will need more expensive and heavier wires, so higher voltages will be an advantage. But the higher voltages are more difficult to insulate, plug in, and switch safely. So there must be a compromise with the supply to the charging circuit. The voltage will probably be less than 1 kV, supplying a maximum current of 120 A.
 

anorlunda

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I noticed that when ads talking about new electric cars they mention 800 v or 200kva for what they called fast or super charging technology .
Also bear in mind that the voltage supplied to a charger may be selected to minimize the cost of the wiring to supply it. It need not have any relationship to the voltage supplied to the battery.

200kva @120V means 1800 amps! That would be silly. It would require very expensive cables and circuit breakers.

My laptop charges at 19V, but the energy comes partially from Canada at voltages as high as 765KV on the way here.
 

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