# CAN bus resistor



## evmetro (Apr 9, 2012)

I am ordering 120 ohm resistors for CAN bus termination. For some reason none of the radio shacks in my area stock 120, 60, or 240 ohm, and the Frys electronics store is out of stock. Anyway, I see that there is a 1/4 watt, or 1/2 watt, and there are metal film or carbon film, and there are also ratings for 1%, 2% and 5%. What is the optimum selection? The price is trivial and since I have to order them on the internet, I should get the best solution.


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## frodus (Apr 12, 2008)

They don't need to be a high tolerance part.... just there for termination. 5% should work just fine.

What are you using it with? Doesn't the curtis and orion BMS have a termination resistor built in?


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## evmetro (Apr 9, 2012)

frodus said:


> They don't need to be a high tolerance part.... just there for termination. 5% should work just fine.
> 
> What are you using it with? Doesn't the curtis and orion BMS have a termination resistor built in?


OK, 5% it is. Any difference on what kind of film or 1/4 watt vs 1/2 watt?

I want to place them on each side of this, as per the HPEVS diagram. Now that you mention it, I did special order the Orion with a termination resistor on both CAN bus leads instead of just the longer lead. While I have you here, I see that there are ground terminals on this Canop box... I am assuming that these are only needed for the CAN wire shielding? The diagram does not show them being used, since the Curtis harness CAN leads do not have shielding...









.


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## frodus (Apr 12, 2008)

They're really really low power, 1/8W is what I usually use.

I can't see the image, blocked at work, can you email it to me?


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## evmetro (Apr 9, 2012)

Now I am embarrassed... I just saw that the diagram does specify 1/4 watt. I don't know how many times that I have looked at that diagram and not noticed that...


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## twright (Aug 20, 2013)

My Orion BMS came with a few spare 120 ohm resistors. I didn't have to buy any!

Give them a call. I'll bet yours is being shipped with a few spares, too.


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