Comparison Marsriva MR-UF800L 800 VA vs Marsriva MR-UF1200 1200 VA

In this case, the input voltage range is implied, in which the UPS is able to supply a stable voltage to the load only due to its own regulators, without switching to the battery. For redundant UPSs (see "Type") this range is quite small, approximately 190 to 260 V; for interactive and especially inverter ones, it is much wider. Some UPS models allow you to manually set the input voltage range.

The maximum output power supplied by the UPS, in other words, the highest apparent load power allowed for this model.

This indicator is measured in volt-amperes (the general meaning of this unit is the same as that of the watt, and different names are used to separate different types of power). The total power consumption of the load, implied in this case, is the sum of two powers — active and reactive. Active power is actually effective power (it is indicated in watts in the characteristics of electrical appliances). Reactive power is the power wasted by coils and capacitors in AC devices; with numerous coils and/or capacitors, this power can be a fairly significant part of the total energy consumption. Note that for simple tasks, you can use data on effective power (it is often given for UPS — see below); but for accurate electrical calculations it is worth using the full one.

The simplest selection rule for this indicator is: the maximum output power of the UPS in volt-amperes should be at least 1.7 times higher than the total load power in watts. There are also more detailed calculation formulas that take into account the characteristics of different types of load; they can be found in special sources. As for specific values, the most modest modern UPSs give out 700 – 1000 VA, or even less — this is enough to power a PC of average performance; and in the most "heavyweight" models, th...is figure can be 8 – 10 kVA and higher.

The effective output power of the UPS is, in fact, the maximum active power of the load that can be connected to the device.

Active power is consumed directly for the operation of the device; it is expressed in watts. In addition to it, most AC devices also consume reactive power, which is "wasted" (relatively speaking) is spent by coils and capacitors. Apparent power (denoted in volt-amperes) is precisely the sum of active and reactive power; it is this characteristic that should be used in accurate electrical calculations. See "Maximum output power" for details; here we note that when selecting a UPS for a relatively simple application, it is quite possible to use only effective power. This is at least easier than converting the watts claimed in the characteristics of the connected devices into full power volt-amps.

The most modest modern "uninterruptibles" give out less than 500 watts. 501 – 1000 W can be considered an average value, 1.1 – 2 kW is above average, and in the most powerful models this figure exceeds 2 kW and can reach very impressive values (up to 1000 kW or more in some industrial class UPS).

The number of outlets connected to the power reserve(battery) provided in the design of the UPS. In order for the UPS to fulfill its main role (providing a backup power in case of power outages), the corresponding electrical appliances must be connected to these outlets. The sockets have a standard shape and are compatible with the vast majority of popular 230 V plugs.

At a minimum, the UPS has 1 or 2 outlets and, in more advanced ones, there may be 3 or more.

The number of USB A connectors provided in the UPS, designed to charge external devices, such as smartphones or tablets.

This number corresponds to the number of gadgets that can be simultaneously charged. True, it is worth considering that not every UPS with this function is able to charge USB devices from its own battery, without external power supply - it is better to check this possibility before buying.

The value of the operating voltage of one complete battery. In most cases, it is 12 V, UPS with 24-volt batteries is a little less common.

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 number of batteries supplied with the UPS.

In general, this parameter is more of a reference than practically significant: the number of batteries is selected in such a way as to provide the desired performance — primarily the time of continuous operation. First of all, it is worth paying attention to such characteristics when choosing.

The type of battery installed in the UPS.

— Fiberglass (AGM). An advanced type of lead-acid battery with electrolyte in an adsorbed state: the compartments of such a battery are filled with porous material, which contains acid. At the same time, the battery case is sealed and AGM models are maintenance-free. This technology is the most popular in batteries for uninterruptible power supplies: it is ideal for batteries operating in buffer mode (that is, when they rarely need to be discharged and, as a rule, little by little). In addition, it provides a long service life, and AGM batteries are inexpensive. The disadvantages of this option include the impossibility of replenishing the electrolyte if it leaks, as well as poor tolerance to overcharging (although the latter becomes irrelevant with a high-quality power controller).

— Gel (GEL). A type of lead-acid battery that uses a gel electrolyte. GEL batteries are best suited for operation in cyclic mode - that is, when the battery needs to power the load for a long time, discharge almost to zero, then charge and again provide long-term autonomous power. But for the buffer mode, in which most UPSs operate (standing on standby for a long time in order to briefly maintain power supply in the event of a failure), this technology is not suitable for a number of reasons. Therefore, it makes sense to purchase such batteries only in cases where t...he “uninterruptible power supply” has to be turned on almost every day - for example, in unstable networks with constant and long-term power outages.

— Lithium-ion (Li-Ion). The key advantages of lithium-ion batteries are high capacity with small dimensions and weight. Also, Li-Ion batteries are not subject to the “memory effect” and can charge quite quickly. Of course, this option is not without its drawbacks - first of all, it is sensitive to low and high temperatures, and if overloaded, the lithium-ion battery can catch fire or even explode. However, thanks to the use of built-in controllers, the likelihood of such “emergency” situations is extremely low and, in general, the advantages of this technology significantly outweigh the disadvantages.

— Lithium iron phosphate (LiFePO4). An advanced modification of lithium-ion batteries (see above), designed to eliminate some of the shortcomings of the original technology. Lithium iron phosphate batteries are characterized by a large number of charge/discharge cycles, chemical and thermal stability, low temperature tolerance, short charging time (including high currents) and safety in operation. The likelihood of an “explosion” of a LiFePO4 battery when overloaded is reduced to almost zero, and in general, such batteries cope with high peak loads without problems and maintain the operating voltage almost until they are fully discharged.