Battery selection is purely application specific and one must select follow the guidelines or recommendations given by electronic device manufacturers. Here is the list of important battery parameters such as ampere-hour capacity, rechargeability, depth of discharge (DOD), lifetime, temperature environments, ruggedness, weight, etc. No battery design is perfect for every application. Choosing one battery requires compromise of features required. You need to prioritize your list of requirements.

Battery Voltage

Normal voltage during discharge, maximum and minimum permissible voltages, discharge curve profile.

Battery type

Primary (disposable) or secondary (rechargeable) battery

Ampere-Hour Capacity

The number of ampere-hours which can be delivered by a battery on a single discharge.

Battery Shelf life

How rapidly the cell loses potential energy while unused.

Battery Service life

Defined either in calendar time or, for secondary cells, possible number of discharge/charge cycles, depending on the battery application. Service life depends on battery design and operational conditions, i.e., the stress put on a battery. For stationary and motive power application, the end of service life is defined as the point at which a battery’s capacity drops to 80% of its original capacity. Exceptions would include car batteries where the service life ends when the capacity falls below 60%.

Duty cycle

Conditions the battery experiences during use. Type of discharge and current drain, e.g., continuous, intermittent, continuous with pulses, etc.

Battery Temperature

In storage and in use. Temperatures that are too high or too low can greatly reduce battery capacity.

Battery Physical Restrictions

These include dimensions, weight, terminals, etc.

Battery Maintenance and Service

Ease of battery acquisition, replacement, charging facilities, disposal.

Battery Safety and Reliability

Failure rates, free from outgassing or leakage, use of toxic components, operation under hazardous conditions, environmentally safe

Battery Cost

Initial cost, operating cost, use of expensive materials

Battery Discharge Rate

Batteries capable of a high-rate discharge must have a low internal resistance.

Energy Density of Battery

It is a measurement of possible stored energy per kilogram of mass. This number is purely theoretical as it does not take into account the mass of inactive materials, nor the variation in chemical reactions.

Power Density of Battery

Power Density P=E/t is energy discharge per time, so the specific power is discussed at a specific discharge rate. It is possible for batteries with a high specific energy to have a low power density if they experience large voltage drops at high discharge rates.

Depth of Discharge

The amount of energy that has been removed from a battery (or battery pack). Usually expressed as a percentage of the total capacity of the battery. For example, 50% depth of discharge means that half of the energy in the battery has been used. 80% DOD means that eighty percent of the energy has been discharged, so the battery now holds only 20% of its full charge.