What Battery to use?

So I am making a robotic arm with 4 SG90 servo motor.
Like this- - YouTube
The main problem I am facing is that my motors are not moving .
Things that are working-

  • The code is working (Link - Code - Pastebin.com)
  • Circuit is also right(same circuit as in the video)

What I think the problem is -
As in the video they used a duracell 9v Battery . But I am using a 9v transistor battery (Link -https://www.amazon.in/Abhithindia-9V-Hi-Watt-Battery-Set/dp/B06XWHBHPT?tag=googinhydr18418-21) .I think that this battery is not capable of controlling the all 4 motors . As the motors are moving a little every 5 seconds or so. Please help me I cant get this thing right for 2 weeks now because I am only a school student . Dont know much about this stuff much . If you have any suggestions please reply. Thanks

Get a proper battery. Those 9V batteries can't move a single servo. A pack of 4xAA or 2x LiPo/Li-ion will do a lot better.

Should I use rechargeable 4*AA batteries?
I mean these ones- https://www.amazon.in/gp/product/B01GHSSWDA/ref=s9_acsd_top_hd_bw_b1W02CF_c_x_w?pf_rd_m=A1VBAL9TL5WCBF&pf_rd_s=merchandised-search-3&pf_rd_r=HWDA2DJ3BCR9HMFSKYFF&pf_rd_r=HWDA2DJ3BCR9HMFSKYFF&pf_rd_t=101&pf_rd_p=228a3dc3-4cee-53a0-8293-3833bc4f2c30&pf_rd_p=228a3dc3-4cee-53a0-8293-3833bc4f2c30&pf_rd_i=1388984031

Voltage is a bit low for the servos (4.8V total) but probably will work. I was thinking alkaline, those produce a bit higher voltage (1.5V nominal so 6V for four of them, a bit more when fully charged).

If going for rechargable I'd go for Li-ion (16450 size), two of them. Total 7.4V nominal, great for the servo and for powering the Arduino via the RAW pin.

Personally I always use NiMH rechargeable cells with servos (my model aircraft background probably). They will generally deliver higher currents than most consumer primary AA batteries and of course you don't have to keep throwing them away when they're empty. And if you really need a higher voltage just use 5 cells.

Steve

Thanks for the response .But I am on a budget here so what is the cheapest way to do it for now?

Short term cheapest: alkaline AA batteries.
Long term cheapest: rechargeable batteries (either type - NiMH or Li-ion will do great; NiMH is probably cheaper).