led lights

[parm]

non boaty but need advice

looking a set of led lights foe a display outside a shop.
Am i right in thinking that i could buy these 5M Led Strip 12V Waterproof red white blue green purple yellow IP65 300SMD DIY | eBay and wire them direct to a small 12v battery and they would work fine and would i get a decent time out of a say 12v 12ah motorbike battery?
no power supply outside shop and i don't need someone tripping over extension leads.

Thanks

[jyasaki]

Sounds right, but your run time will depend on exactly how they have the LED's wired up. Normal is each in parallel with a drop resistor, and the value of that determines the current drawn per LED. Sometimes you'll have a number of LED's per circuit, which will increase efficiency at the expense of limiting where you can cut the strip.

jky

[parm]

ok thanks for that

[Phil M]

Be a little careful as ideally you need a 12v constant voltage supply. A 12v battery will vary from almost 15v down to 10-11 when flat so you will get considerable dimming over that range and may damage the LED's with the high initial input voltage. You can get LED constant voltage drivers which take an un-regulated 12v input and provide a regulated output, and may even offer some controllable dimming. I'd look for you but have to head out to a meeting. Google shoudl turn something up. As I recall, they are in the region of £10-20.

Phil