# Forum: Analog Circuits The Arrhenius constants α and β

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Hello together,
How can i get the Arrhenius constants α and β from the information
the Simulink® library of the battery block?

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Hello together,
How can i get the Arrhenius constants α and β from the information
the Simulink® library of the battery block?.

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Hi Guy!
It is Christmas!

Cherish this time!

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Well,

the ln is nothing else than the logarithm to the base e.

But if a logarithm has the same argument as its base, that is equal to 1
by definition.

That means, divide K(T,ref) and R(T,ref) to switch it on left side.
Now multiplicate with ln (left and right side. That means for right side
follwing facts:
ln^(e) = 1
1 × your alpha oder beta term. The alpha and beta part comes now out /
down from exp. part.
For left side you have to consider the ln calculation rules:
ln(R/R(T,ref)).
The Temperature terms on the right side can you easily handle with a
division and you will get alpha and beta free.
I hope that helps you.

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thanks for the feedback though
that wasn't what I meant because R(T) and K(T) are unknown.
The only question was how I alpha and beta from the information
the Simulink battery block library could get

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Ah ok,.. for my understanding:

You should find out the R and K value over a thereotical estimation or
lab trials. For my opinion: alpha and beta are open values which are
maybe not further defined in Simulink. Well, more details are given in
literature, or Simulink Help Section for a definition  of different
battery material setups? But, i dont know it sure.

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Marouen B. schrieb:
> (The only question was how I alpha and beta) x -1 = Fatal error