How many watts can the CA pass through the external power?

[rsilvers]

I got this:

http://www.amazon.com/gp/product/B00GFLQMAK?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Which draws X watts (I assume about 10).

I also got this:

http://www.amazon.com/gp/product/B00KV2NGGC?psc=1&redirect=true&ref_=oh_aui_detailpage_o07_s00

Which claims to pass 15 watts.

Plugging the light into a USB wall outlet works great. Plugging it into a juice pack works great. Plugging it into the DC-DC converter's USB hooked up to the power outlet on my V3CA does not work.

Plugging my iPhone into the DC-DC converter's USB works fine.

So either the CA's output cannot provide enough watts for this light, or the DC-DC converter cannot. I don't want to undo all of my solder and heat-shrink tubing to test each one.

How many watts can a CA output?

 

[rsilvers]

I used a USB power meter.

The light draws 4.73v and 1.53a. On another USB port, it drew 4.68v and 1.58a.

So about 7.3 watts. And the DC-DC is about 15% waste heat, so the CA is probably seeing 8.5 watts.

Weird - now the light is working when plugged into the DC-DC that is hooked up to the CA. I think I am all set. This is an awesome way to set up a bike light for $18 total (light + DC-DC).

Though if I were doing it again, I would consider the $12 DC-DC that has two USB outputs so that I can have the phone charging and the light on at the same time. Then again, maybe that would be too much power draw. Probably that would overload the DC-DC or the CA.

 

[rsilvers]

I tried it again and it didn't work again.

I also noticed that my phone battery case would blink that it was charging, but would not charge my phone at the same time as normal. So I put the USB power meter back on, and noticed that my phone with battery case was only drawing 0.2 amps.

I think this is the solution:

http://www.amazon.com/gp/product/B00T0DW3F8?psc=1&redirect=true&ref_=oh_aui_detailpage_o07_s00

It tricks certain devices into drawing more power by combining the data and power lines. Evidently the DC-DC converter does not really handle power in the best way.

 

[Gregory]

I saw tekelectik (sp?) post that the CAV3 has a 1A polyfuse (used to be 500mA on the V2.3) on the AUX line.

So with a 48V battery your device could use up to 50W ? (including efficiency losses, peaks)