Cycle Analyst, Accessories, Voltage Question

[cbr shadow]

Maybe someone can explain how the CA and the accessories cable coming off of it work..
I'm running 100v on the ebike right now, and I notice that the CA gets the full 100v out of its accessory cable to feed things like a headlight. The headlight would have to be able to accept 100v @ very low amps though, right? That's because the wires going to the CA are very thin, which is fine for high voltage if low current. So to run a headlight on my bike I'd either need to find one that accepts 100v low amps, or run a DC/DC convertor from the main power line, not from the CA.
Does this all sound right? What if instead of 100v I went with a 24v setup? Then the accessory cable would be running 24v at low amps which wouldn't be able to power much of anything, I'd think.
Thoughts? Am I way off base here?

 

[dogman dan]

I think Justin sized everything on his CA pack voltage output cable to run the stuff he sells. So the cyclelumenator doesn't pull much amps, why give it a beefy wire? It's not intended to be a car jump start port. I don't have a CA that new though, so I have no clue what amps it can carry.

I'd think that if you wanted to use an AC 500w halogen fixture for your headlight, it would fry the wires.

 

[justin_le]

The headlight would have to be able to accept 100v @ very low amps though, right? That's because the wires going to the CA are very thin, which is fine for high voltage if low current. So to run a headlight on my bike I'd either need to find one that accepts 100v low amps, or run a DC/DC convertor from the main power line, not from the CA.
Does this all sound right?

That's exactly correct. You shouldn't pull more than about 0.5 amps from that port, and so the resulting power capability depends on your system voltage.

What if instead of 100v I went with a 24v setup? Then the accessory cable would be running 24v at low amps which wouldn't be able to power much of anything, I'd think.
Thoughts? Am I way off base here?

No you are right on the mark. With a 24V pack you'd be more in the 10-15 watt territory, which is still plenty of brightness in a good headlamp but less than what some people like to run. At ebike voltages 0.5 amps is still more than enough power for most accessories you'd want at the handlebar (headlights, handgrip warmer, ipod charger etc.) but if you're trying to shoot a high power laser or run a small motor or something you'll nee to run a fresh set of cables to your battery and not tap into the CA's supply.

I think Justin sized everything on his CA pack voltage output cable to run the stuff he sells. So the cyclelumenator doesn't pull much amps, why give it a beefy wire?

It's more that the original 6-conductor lead wire between the CA and the controller was never anticipated to be used as a power source and wasn't spec'd as such. If you get upwards of 1A of current draw, you'll end up with too much voltage drop between the CA's ground and the ground at the motor controller which can mess the signals up. We're looking at having a custom 6-conductor cable fabricated with a heavier gauge red and black power wire and thinner gauge on the remaining signals so that we can boost this power capability a bit. Still waiting to hear how many 1000's of meters the minimum length will be!

-Justin

 

[dogman dan]

Thanks for the clarification Justin. Easy enough to run a fat wire to the battery, or controller input for a large watt hog light. What you designed is perfect for a led light.

At one point I ran a pretty watt hog halogen 24v light from an EVG. I found it quite simple to just run it on a nicad drill battery.