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.
Parallel batteries are connected in such a way that the current of each battery is added together while the voltage remains the same. So, if you had two 12-volt batteries in parallel, they would produce 12 volts with twice the amount of current. How Do You Wire a Series and Parallel Circuit Simultaneously?
Batteries in parallel When batteries are connected side by parallel, their positive and negative parts link together. This makes a group where each battery keeps its voltage. But, the total power and how much it can do go up. For example, suppose two 1.5-volt batteries with different sizes are connected in parallel.
Batteries in series are connected end to end so that the voltage of each battery is added together. This can be useful if you need a higher voltage for something like an electric car. Batteries in parallel are connected side by side so that the current of each battery is added together.
In general, it is best to connect batteries in series because this increases the voltage while keeping the current the same. However, there are some advantages to connecting batteries in parallel. For example, if you want to increase the current without changing the voltage, then connecting batteries in parallel is the way to go.
Although it is never advisable to connect two non identical batteries in parallel because it does not make any sense it is useless and may destroy the batteries. In short, when two non-identical batteries are connected in parallel, current will flow from higher voltage battery to lower voltage battery. Which is not good.