I don't have a switch for the KSI. The controller is always seeing the full pack voltage at the KSI. Is that OK? It's been that way for about a few weeks now, and nothing horrible has happened yet. How much power is the controller using by doing that? Will it wear out any components?
It's more of a safety issue then component or power issue. The KSI is one of the links in your chain of safety features. I have run my motorcycle for years with the KSI wired directly to B+ without ill effect.
On my truck I have the KSI wired to the microswitch on my pot box so that if the accelerator is not depressed the controller is not on.
paul holmes wrote:
> I don't have a switch for the KSI. The controller is always seeing
> the full pack voltage at the KSI. Is that OK? It's been that way
> for about a few weeks now, and nothing horrible has happened yet.
> How much power is the controller using by doing that? Will it wear
> out any components?
You didn't say what model controller, but "KSI" makes me guess it is a
Curtis. The Curtis controller KSI input draws about 20 ma, so your pack
will be delivering this current all the time. It won't wear anything
out, but has other effects.
20ma from a 50ah pack will run it dead in a few months if you don't
charge. Running the batteries completely dead would probably destroy
them. While you wouldn't normally do this, it could happen if your EV is
down for some other repair or upgrade.
The other worry is that the pack voltage can get quite high during
charging. It's common for people to use a 120v rated controller on a
120v pack (i.e. no safety margin). During charging, a 120v pack can
easily get to 160v. That's really too high for the controller, and will
shorten its life.
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