where can i buy a battery powered hair straightener?

These wholesale hair accessories are very practical, and can provide a variety of needs to the ladies. Fashion and beautiful can be fully reflected.

Those straighteners with battery usually are low quality and can damage your hair.  I recommend you a better hair straightener that keeps the hair soft, shiny and very straight, it's the Karmin G3 Salon Pro which has tourmaline ceramic plates that cause less damage to the hair, it's dual voltage, heats up to 460F for all hair textures and leaves the hair soft, shiny, frizz less and super straight.  
Good luck. :D

Amazon has a Hot Tools iron selling for $26.95
specifics:

Low Price Beauty Supply has an Ion FX iron selling for $166.99
specifics:
Our patent pending ceramic heater and its elements are far superior to what is currently being employed by all other manufactures. Our heater requires less ten percent of the electricity needed to heat the nano silver tourmaline ceramic plates than traditional ceramic heaters. By marring the custom made rechargeable lithium ion batteries, the ceramic plates and quality controlled in house manufacturing process we have created the ultimate cordless flat iron. The lithium ion batteries installed in the iron were created by one of the leading battery manufacture in the world. They are rated for over one thousand five hundred (1,500+) refresh cycles; they can be recharged every single day for over four years with very little loss of performance. The batteries also have no memory, meaning they recharge only what is needed. They do not need to be drained and fully recharged for many hours like traditional rechargeable batteries. The ceramic plates are infused with tourmaline and nano silver (AG+). Tourmaline is a crystal that when heated naturally emits negative ions that help close the hair cuticle and seal in moisture. Nano silver is literally silver that has been dissected to the point where it atomic structure is one tenth of a diameter of a single hair strand. Nano silver naturally sterilizes and deodorizes pathogens without causing any known harm to the human body. Before the invention of penicillin, silver was extensively used to cure ailments. Far infra-red heat penetrates deep inside the cortex of the hair shaft because it has the longest wavelength of light that cannot be naturally seen. Our patented ceramic heater uses a very long infra-red wavelength for optimal straightening and minimal damage because the heat radiates from inside the hair shaft towards the outside. It has taken us over two years to break through the technological boundaries of creating the true cordless flat iron. We overcame five very difficult limitations of technology that the imitators to come will have a hard time following. We will continue to improve and refine. We will be the leader of this new frontier.