ebike battery for headlights/tail, charging phone, rear camera, etc.

[polyphasic]

I'm not savvy about electrical mods, however I'd like to run my headlight and tail off the ebike battery rather than buying say a Light & Motion system. Also would like to charge my iphone using the ebike battery.

I imagine this is just a converter to reduce the voltage from say 36 volts to 5 volts for the iphone and whatever a light would run on. Has anybody here done this or have ideas on how to run lights off your electric bike's battery?

 

[cwah]

I've used a 72V to 12V DC-DC converter:
http://www.pedelecs.co.uk/forum/electric-bicycles/11593-how-connect-dc-dc-converter.html

The probblem you're going to have is that to charge your iphone you need 5V supply, but for other things such as light it would be around 8V or 12V.

I'm just using a 12V converter and only use 12V light so it's much more simpler. I have a second 12V to 5V converter in case I want to use it as a secondary charger but I don't need to use it for now.

 

[Scimitar]

There's a wrinkle I've read about on ES - grab an old phone charger and put the battery DC voltage into where the mains pins are - you should get phone voltage out of the front. These chargers are mini SMPSs so don't much care what the input voltage is - up to a point.
If that works, strip down the charger and re-case it or at least get rid of the pins.