Driving a 12V COB LED ring with a portable battery (beginner's headache)

[Griffevent]

Hello everyone,
I'm a French student in literature, so get ready to see plenty of mistakes in the following post (either concerning electronic or basic English).
I need your help concerning a little project I'm trying to make, but I keep getting slowed down by my misunderstandings of electronics. I read the thread "Got a question about driving LEDs?" but I can't find the answers here either.

I'm trying to build a portable led ring mounted on an aluminium lens hood to do some macrophotography.

I've got a COB led ring bought for cheap on a chinese website. The specs' indicate 12W / 12W (so it should draw 1Ah ?), and no resistors are included. Hooked to a car battery (for testing), the light is too strong. It's perfect when hooked to a 10.8V Li-ion hand-drill battery (and it's light and easy to carry).
Thus, I am looking for an efficient way to drive it.

> Is it hasardous to hook the 10.8V battery to it without any regulator in the circuit ?
> Does a more efficient way to power it exist ? It's basically 3x 18650 isn't it ?
> I can't measure the amps when hooked to the car battery, but a colleague of mine says 12W looks suspicious.

Voilà.
Thanks in advance for your help.

 

[Colin Mitchell]

If the LED strip has built-in resistors,simply put a string of 4 x 1N4004 diodes on the positive wire.

 

[Griffevent]

The specs are lacking in the item description. But according to a website about some extremely similar rings : "There are no resistors on the ring itself, rather, the power is supplied at a constant current through an external regulator, which is then plugged into a 12V source." So I suppose it doesn't have built-in-resistors.

Here is a picture of the led ring :

 

[davenn]

Here is a picture of the led ring :

pic isn't showing

 

[Griffevent]

Here is a working link : http://i.picpar.com/yjsb.png