Comparison APC Back-UPS 650VA BE650G2-GR 650 VA vs APC Back-UPS 650VA BE650G2-RS 650 VA

UPS continuous operation time from a fully charged battery when connected to a load with a power equal to the UPS output power (maximum or effective, depending on the type of load, see the relevant paragraphs for details). For a UPS designed to work with a home or office PC, a time of about 10-15 minutes is considered sufficient, this is enough to save data and complete work. To power servers, it is worth using devices with an operating time of 20 minutes or more.

UPS continuous operation time from a fully charged battery when connected to a load with a power equal to half the output power of the UPS (maximum or effective, depending on the type of load, see below for details). The operating time with such a load is much longer than for a full load, and even in the simplest models it can reach 20-30 minutes.

Efficiency (coefficient of performance) in the case of a UPS is the ratio of its output power to the power consumed from the network. This is one of the main parameters that determine the overall efficiency of the device: the higher the efficiency, the less energy the UPS wastes (due to heating parts, electromagnetic radiation, etc.). In modern models, the efficiency value can reach 99%.

- Lead acid. Structurally, lead-acid batteries are based on a combination of electrodes made of lead compounds immersed in a liquid electrolyte, the role of which is played by an aqueous solution of sulfuric acid. The advantages of this type are simplicity and low cost, low self-discharge, no "memory effect" and maintaining performance in a wide temperature range. At the same time, the less charge remains in such batteries, the less current they produce. Also, lead-acid batteries are afraid of deep discharges, take a long time to charge, have large dimensions and weight in the context of other types.

- Lead-acid (AGM). An advanced type of lead-acid battery with an electrolyte in a jelly-like state. The gel electrolyte provides maximum contact with the negative and positive plates while maintaining a uniform consistency throughout the volume. AGM batteries impress with their high reliability, low self-discharge, deep discharge resistance and long service life. However, they are sensitive to charge quality, short circuits and negative temperatures.

— Li-Ion. Lithium-ion batteries have a high capacity with small dimensions and weight. They are not subject to the “memory effect”, they are able to charge quite quickly, they can boast of an excellent reserve for charge-discharge cycles. Li-Ion batteries also have disadvantages - first of all, it is sensitivity to low or high temperatures, and when overloaded, such a battery can catch fire or even explode. Howeve...r, due to the use of embedded controllers, the likelihood of such "accidents" is extremely small and, in general, the advantages of this technology significantly outweigh the disadvantages.

The capacity of the battery installed in the UPS. For models with multiple batteries, this is both the total working capacity and the capacity of each individual battery: the batteries in such devices are usually connected in series, so that their total capacity corresponds to the capacity of each individual cell.

Theoretically, a higher battery capacity means the ability to power loads of a given capacity for longer. However, in fact, this parameter is more of a reference than practically significant. The fact is that the actual amount of energy stored by the battery depends not only on the capacity in amp-hours, but also on the voltage in volts; this voltage is often not specified in the characteristics, despite the fact that for accurate calculations it must be known. So when choosing, you should focus on more "close to life" characteristics — first of all, on the directly claimed operating time in different modes (see above).

The ability to turn on the uninterruptible power supply in the "cold start" mode.

A cold start is a turn-on mode in which there is no external power, and the load connected to the UPS is powered immediately from the uninterruptible battery (which, of course, must be charged). This mode is especially useful in emergency cases — for example, if you urgently need to print a document, but there is no light.