I am working on my first project. It'll be an humanoid-like robot powered by an Arduino Nano with four SG90 servos in each limb, a bluetooth module, an ultrassonic sensor and a 8x8 led matrix (I'm not sure about this one though).
What type of batteries should I use? Would a 6V 3A battery be enough? Should I use 4 small batteries?
Thank you in advance! I'm sorry if this is a stupid question, I just don't have anyone to help me.
Each of those plastic geared servos want about 800mA to be available; call it 1 amp. For 4 servos you'd want at least 4 amps of available current per hour. Then there is the rest of the circuit.
Curiously missing is any specification of the recommended maximum discharge rate for this lack.
The r/c picks I use (Lipo chemistry) have a C rating for discharge. A 1000 mAh battery might have a 40C/80C rating, meaning we could safely take 40 Amperes continuously and bursty spikes of 80.
The 12 AWG wire is a clue to the expectation of the manufacturer, but only.
Most likely rechargeable, as they will go fast. Battery lifetime can be roughly estimated by measuring the average current draw of your project in Amperes (A), and divide that figure into the battery capacity in Ah.
lifetime in hours ~ (capacity in Ah)/(current draw in A).
Battery capacity in mAh and current in mA can also be used for this calculation.