Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: what kind of batteries does this take?
Document: Worked the first two times, then had to replace the batteries. worked again for a short time and batteries went dead. Repeated...again. Unreliable for any professional. I am not a professional and primarily bought this to minimize influence from holding the camera while attempting to take long range photos of wildlife.
Works great and came with batteries. Such an awesome accessory to have with a digital camera. Sold for a great price too!
hard to use.. battery dead on arrival... i went tobought new batteries and after 2 uses iremote stopped working..do not buy
The batteries are not the same...so I could do no further trouble shooting and am not sure what the original problem was. Best not to even consider this unit and save yourself from possible headaches.
Still playing around with it, so not sure if it works. Maybe I need new batteries. It's cheap, so you get what you pay for. Still hopeful that it's just user error
This unit drains batteries very quickly. I had to change two batteries within a month's time. It looks like it's draining batteries even when it's sitting idle.
Worked great for the week that I used it. Put this remote away with my camera bag for a month and found that it never worked after that. Never tried replacing the batteries, but it did work flawlessly with my Rebel t2i when new.
I was a bit skeptical of this since it was so inexpensive, but figured if it ended up not working, I was only losing a few bucks. Fortunately, it works flawlessly! The batteries last a good long time and the shutter is responsive and quick. Very satisfied.
You get what you pay for. Does not work what so ever. Tried new batteries and every angle and length from cam possible. ust to be sure, purchased different generic remote locally, works just fine. Cam is Canon 60D.
luckily the control came in its box complete with instructions on how to use it. and it uses those round flat batteries. you could use it in a pretty far range i tested it to about 10ft away. and in different angles.I would definitely recommend it for photographers on a budget.
Answer: Lithium cell cr2025 3v it's one of the button cell ones, I'm sure any of the same size will work