How to determine the battery life of a digital camera

Digital technology is so firmly entrenched in everyday life that many such devices have taken for granted. This is exactly what happened with digital cameras, which somehow quietly supplanted their film counterparts.

What could be simpler than going to a home appliance store and buying your favorite model of a camera - fortunately, the lower limit of their cost is constantly decreasing. Together with a digital camera, a set of finger batteries and Charger to them, which allows you not to depend on constant purchases of disposable batteries.

A little time passes and the happy owner of photographic equipment begins to notice that the battery charge is enough for an ever smaller number of shots. Moreover, which causes an unpleasant precipitate in the shower, a friend has exactly the same batteries working 2-3 times longer, however, in a different brand of camera. There are no miracles in electrical engineering, so let's try to figure out the reasons for this difference.

Batteries that are always in short supply

Finger batteries are chemical sources of direct current. Under the action of the charging current, chemical reactions occur inside the battery, as a result of which it acquires the ability to give up the accumulated charge when the load is connected. There are a large number of different batteries. The most common types are nickel-cadmium, nickel-metal hydride, and lithium-ion batteries. About how they are arranged, their advantages and disadvantages, see the article Popular Battery Types.

Although these current sources have several important characteristics: internal resistance, the level of natural self-discharge, the number of cycles, buyers pay attention, first of all, to the capacity in milliamps. For example, everyone understands that a battery with a capacity of 2700 mAh should work longer than a model with a capacity of 1800 mAh. With some reservations, this is true.

So different cameras

Any digital camera for its work consumes electric current from energy sources (batteries). The higher its value, the fewer pictures can be taken before the next charge. Some manufacturers are developing truly economical digital cameras, while others, for some reason, ignore this option. Knowing the current consumption of the device and the battery capacity, we can roughly calculate how long the battery pack used will last.

Measure current

To measure the current consumption you will need: milliammeter or multimeteras well as a camera and charged batteries.

The ammeter has a low own resistance, so it is connected in series. If we consider the method of connecting the batteries, it becomes clear that they are connected in series, giving out 3 Volts (1.5 V * 2) to the load. This method of connecting two batteries simplifies current measurement: just close the batteries with a milliammeter probe and turn on the camera.

Some models have a special lock button in their design, a kind of open cover sensor: if the battery cover is open and the button is not pressed, the camera cannot be turned on. In this model, you do not need to look for it, because it is in plain sight.

We press the lock button and, without releasing it, the power button of the camera. Wherein multimeter probes must be firmly in contact with the batteries in the compartment. The screen displays 171.5 mA. This is the current that this digital camera consumes in normal operation (without flash, with the viewfinder display turned on).

All camera models are characterized by different levels of charge consumption. That is why their battery life is so different. In terms of uptime, the lower the consumption, the better.

Source capacity and current consumption

The battery capacity indicated by the manufacturer is unattainable in practice, because the device will require their replacement long before the battery is completely depleted. The nominal voltage of each 1.2 V battery instead of the standard 1.5 V makes the situation even worse. The problem, alas, is not solved by choosing the type of battery in the menu.

To estimate the operating time (number of shots), it is necessary to compare the value of current consumption with the capacity of the batteries. For example, popular batteries with 2700 mAh, theoretically, can work under such conditions until recharging for at least 15 hours (2700 mAh / 170 mA). If we take into account the incomplete discharge and the lack of ideal conditions, then the time obtained should be reduced by 2-2.5 times.

Dmitry Babin