Yes, parallel batteries "can" supply twice the current when the load is less than the ESR of the battery. ( As shown above, for short circuit current, it is twice.
How does a battery increase the current in a circuit?
Each battery can pump a set number of electrons per second, for a given circuit, so if two or more batteries are connected in parallel the number of electrons they push out each second and energy supplied is added, hence the total current in the circuit is increased. When voltage increases the current?
Does adding a battery in parallel increase current?
Batteries are normally rated in Ampere-hours (Ah), not in Amperes. An Ampere-hour is a measure of the energy stored in the battery, and is not directly related to the current that the battery can deliver. By adding a battery in parallel, you do not increase the current. You increase the maximum current that the motor can take.
How does voltage affect a battery?
In a battery, voltage determines how strongly electrons are pushed through a circuit, much like pressure determines how strongly water is pushed through a hose. Most AAA, AA, C and D batteries are around 1.5 volts. Imagine the batteries shown in the diagram are rated at 1.5 volts and 500 milliamp-hours.
What happens if you add multiple batteries in a circuit?
Adding multiple batteries in a circuit increases the voltage of the batteries, but the total capacity of the circuit will be the same. Unlike batteries connected in a parallel configuration, batteries connected in a series configuration give an increased voltage output without changing the amperage of the circuit measured in amp-hours.
If there isn't enough current and you add a battery, you can expect increase in torque because the voltage supplied by the batteries will be higher. This was a fantastic answer. Thank you for correcting my misconception -- I did not know that the resistance of a motor is constant.
Yes, parallel batteries "can" supply twice the current when the load is less than the ESR of the battery. ( As shown above, for short circuit current, it is twice.) But otherwise, when the load is equal to battery ESR, the current is the same. With series cells it greater when the load R is higher than ESR, the higher V/R produces a higher current.