Pale Blue Earth sells rechargeable lithium-ion batteries in all the most popular form factors. These include AA, AAA, C, D, and 9V batteries. A common question in this regard is why these standard form factors exist. People wonder if the unit size has anything to do with the amount of power a battery holds.
If energy density were the only measurement, you could make the case that form factor affects how much power a battery holds. But when it actually comes to operating things from battery power, energy density is less important than voltage and current.
How Batteries Are Rated
Form factor and battery power are unrelated only in the sense that battery power is not measured in a tangible volume – like quarts of water or gallons of milk. If you look at our D and C batteries, you will notice that they are both 1.5V cells despite being different form factors.
How those batteries are arranged in an electronic device determines usable voltage and current. You have two options:
In Parallel – A parallel arrangement drains energy from all the batteries in a pack simultaneously without increasing the voltage connected to the circuit/host product.
In Series – A serial arrangement utilizes all the batteries in the pack connected end-to-end. D batteries placed end-to-end in a flashlight offer a clear enough example. This results in the voltages adding up, creating a higher potential power output to the circuit/host product.
So, what difference does the arrangement make? Imagine you have four batteries at 1.5V each, arranged in a parallel scenario. Measured in volts, the total output will still be 1.5V. However, in a given product, the arrangement will produce four times the current a single battery would produce.
Those same four batteries arranged in series would produce just the opposite. Total current would be no more than what a single battery would provide. Yet voltage would be four times that amount, or 6V.
The Difference Between Voltage and Current
The best way to understand voltage and current is to think of a garden hose. If you leave one end of the hose open and turn on the water, you will notice it flows out the end at a consistent rate. Battery current is very similar. It is the rate at which electric charge flows through the circuit.
If you took that same hose and put a spray head on the end, turning on the water would create pressure in the hose. Voltage is similar in the battery world. It measures the amount of force by which electrons pass through the circuit.
How It Relates to Form Factor
So, how does all of this relate to form factor and the amount of power a battery delivers? Generally, larger form factors are used in products that require more power output or more current capacity. A small flashlight may run on AAA or AAA, a large high output flashlight may require C or D batteries.
So, even though the batteries are all 1.5V, different products will require different current outputs and may need more or less capacity to ensure the user gets enough use time out of one set of batteries. At a given voltage, the greater the current, the more power the battery consistently delivers under load.
Paleblue batteries have stable voltage from start to finish, a real benefit in comparison to the voltage decay that alkaline and NiMh batteries have. This decay can affect the product performance over time. Imagine your flashlight getting dimmer and dimmer as the voltage dropped. You might actually throw away alkaline batteries well before they are fully drained if your flashlight brightness has gone down too much. This won’t happen with Paleblue, thanks to the fact that they are Lithium-ion and each battery has its own battery management system circuit onboard to manage the voltage.