With an electric car plug standard about to be finalized, and charging stations beginning to pop up in the U.Sand Europe, an important question to ask is: How long will it take to fill up a car battery? And like most technical matters, the answer is, "It depends."

Automobile batteries, whether they are nickel-metal hydride or lithium-ion, can be made up of many cells, with larger cell quantities capable of a larger storage capacityThe trade off, however, is that cars with more capacity are more expensive, heavier, produce more heat and take longer to chargeBattery life is also influenced by how "deeply" the battery charges and dischargesFor example, the Toyota Prius only allows its battery to be charged to 80% of full capacity, as going beyond this point can lead to overheating (thermal runaway) and excessive gassing, resulting in a decline in battery lifeAll this means that the type of car you own will play a factor.

The other major factor in charge times is the type of charging system being usedThe standard wall socket in most U.Sgarages outputs 120 Volts at 20 Amps of currentMultiplying these units together provides the Watts, or energy per unit of timeWith this amount of power, it could take a whole night (8+ hours) to get the full electrical storage into a batteryTypical European outlets produce 230 Volts at around 16 Amps, perhaps shaving a couple hours off charging times.

For car owners wanting to drive far distances without the impossible hassle of waiting 8 hours between charges, there are a couple options availableIn the U.S., plug-in charging stations will provide thick power cables that make it possible to deliver the 240 Volts at 70 Amps that the plug standard is designed to handle - this would make it possible to fully charge a vehicle in an hour or twoIn Europe, the plug specifications provide for 400 Volts at 63 AmpsTheoretically, this can allow a waiting time measured in mere minutes! However, with that sort of power, there is a real risk of battery damage.

Home owners also have the option of using the high powered connections in their homes that are reserved for equipment such as air conditionersThey may also buy extra equipment, like personal charging stations, at a steep priceUnfortunately, residents who live in apartment buildings will not have access to many of these options.

For individuals who only drive short distances each day, simply charging their car overnight shoud be practical and simpleOther prospective buyers will have to take into account the charging options available to them, as well as the vehicle itselfAnd in the not-so-distant future, advancements in battery technology can be expected to further change the equation.