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SuKam Inverter/UPS Review 2019

By on January 3, 2019 with 21 Comments  

Su Kam is one of the most trusted brands in the power inverter/UPS segment. In fact, it is the first inverter company in India to work with 90% efficiency. For starters, power inverter (or simply an inverter) is a simple electronic device that stores electricity from the main supply in a battery and uses the DC (direct current) from the battery and converts it into AC (alternating current) that is used by the household appliances. Although inverter and UPS (uninterrupted power supply) are often used interchangeably they are slightly different. The main difference between the UPS and inverter lies in the time in which it can switch to the battery power right after the power cut. Where an inverter can take roughly around 100 milli seconds (0.1 seconds) for this switching, a UPS can switch to the battery in just 3-5 milli seconds. Now, the choice between the two will depend on the criticality of switching for backing up the appliances that you will need. For e.g. a desktop computer would need faster switching as it may lose the data if it switches off even for a few milli seconds. Similarly, faster switching is critical for industrial applications like running medical/biomedical devices at the hospital, workstations, and servers at data centers, and for other security devices.

Su Kam provides a complete range of solutions to match different needs—from inverters to UPS, from residential to commercial, from low KVA to high KVA, from general purpose to solar based. Su Kam has something for everyone. Moreover, it also supplies batteries which would be needed alongside the inverter. Established 20 years back, Su Kam has a strong presence all across India with 25,000 dealers and easy availability on a various e-commerce platform. Su Kam also exports its products to more than 70 countries. That’s because Su Kam products often come with the state-of-the-art technologies in their products. In this article, we will talk about key technologies that the latest Su Kam inverters come with.

Key SuKam Inverter Technologies

Automatic Temperature Compensation (ATC) to Supply Correct Boost Voltage

Often the central and northern parts of India witness extreme temperatures in summers and winters. People residing here often complain that their inverter is working fine, but their battery keeps giving trouble. Now the battery used with the inverter is often expensive and its life is limited too (few years depending on the type of the battery). Apart from this, battery backup is usually less, and it requires the frequent input of water. All these are typical problems with the ordinary inverter because they charge the battery alike in all seasons—be it scorching summers or bone-chilling winters or an optimal autumn. Once the battery nears the full capacity, normal inverter charges the battery with something called boost voltage whose value is kept fixed at 14.4 V. If someone has a 12 V tubular battery installed, then this battery comes to 14.4 V when it is fully charged, after which, the battery doesn’t charge anymore. This is called the boost voltage.


This fixation of 14.4 V is based on assumption that surrounding temperature is 25oC. This value is set to avoid battery overcharging. But a normal inverter ignores a very critical factor—which is the outside temperature. Now no place in India has a constant temperature of 25oC. Boost voltage requirement is actually a function of time i.e it varies with varying the temperature. As seen from the table below, 14.4 V is for 25o Celsius. Now, India being majorly tropical in nature, temperature crosses 40 degrees Celsius in many parts of the country. So, during peak summers boost voltage needed would 14.13 V or lesser. But when the ordinary inverter supplies 14.4 V even in this hot climatic condition it results in heating of the battery and would evaporate water in the battery (water is needed for electrolytic reaction), which would, in turn, reduce the battery life. At times, the temperature of the battery increases so much that it starts emitting smoke which can be hazardous. Moreover, charging the battery on constant high voltage (than needed) results in an increased electricity consumption.

On the other hand, during winter when the temperature may reach 0o Celsius (depending on the geographic location), a normal inverter would not be able to charge the battery completely. This is because the water in the battery starts to freeze and thus hinders the battery backup process. This results in constant undercharging. There comes a time when the battery ceases to charge after a certain level. Due to these conditions, the battery is required to be charged with a higher boost voltage (refer to the table), which a normal inverter fails to. We can see in the chart that at 0o Celsius, the boost voltage should have been 14.85 but even in this cold condition, normal inverter charges the battery at predefined 14.40 V.

The solution to all these problems is Automatic Temperature Control (ATC) which was introduced in the latest inverter offering by Su-Kam—the Falcon+ series. Falcon+ comes with a temperature sensor which is connected to the battery and apprises the inverter processor with the surrounding temperature. If the surrounding temperature is 40o Celsius, then Falcon+ charges the battery to the boost voltage of 14.13 V instead of being rigid with 14.4 V. Thus, the battery overcharging, and overheating is avoided. Also, there is no need to continually pour water inside the battery. Similarly, during winters when the surrounding temperature reaches 0o Celsius, then Falcon+ charges the battery not with 14.40 boost voltage but with an optimal boost voltage of 14.85 V. This results in improved battery life. Thus, ATC ensures that at any given temperature, the battery charges at the correct rate.

Automatic Bypass System to Avoid Unnecessary Power Cuts

Normally, when regular power is available, an ordinary inverter helps the load (household appliances connected to the power outlet) work by passing on the main supply while simultaneously charging the battery. Now, if there is an issue in the inverter, then an ordinary inverter will not be able to bypass the mains and would start drawing power from the battery. This would result in momentary discontinuity of the power and would only work till the battery lasts. This means customers need to call an electrician/engineer to fix this issue. Until the inverter is working again, the electrician/engineer provides a temporary solution which is to take the socket out of inverter output and to put it in a mains input socket and work the load temporarily. New inverters in the latest Falcon+ series comes with a static bypass feature. So, even if there is an internal problem in the Su Kam inverter or it stops working, then the static bypass feature comes to the rescue. It bypasses mains and works the load without turning on to the battery for supply of power. This eases the customer’s predicament of frequently calling the inverter service guys and eliminates the need to change the wiring. The static bypass feature in the new Su Kam models makes it unique as compared to other inverters.

6-Stage Battery Charging for Optimal Battery Performance

Battery charging of the inverter/UPS is a multi-stage process. Generally, inverter batteries employ 3-stage charging for the battery. But modern model from Falcon+ series from Su Kam come with 6-stage charging which helps to better utilize the battery and improves its longevity.

Let us see each stage of battery charging of modern Su Kam inverters in more detail:

Stage 1: Desulphation

Generally, inverters don’t come with desulphation stage and directly starts with bulk charge stage for battery charging. But new models of Su Kam inverter from Falcon+ series comes with this stage to remove impurities which can hamper battery charging. In the desulphation stage, Su Kam inverter removes the sulphate crystals which often gets accumulated around the battery plate by passing a high voltage low current micropulse. This stage removes the Sulphur impurities around the battery and maintains the stable internal temperature of the battery.

Stage 2: Soft Start

Normally ordinary inverter starts the charging with bulk charge wherein if mains fail, the load works through the battery. But when the battery starts to discharge, the internal temperature of the battery increases. When the mains are available, a normal inverter starts to charge the battery in bulk charge with full power, due to which, the internal temperature of the battery further increases leading to an overheated battery. But instead of directly starting with bulk charge, modern Su Kam inverters starts with something called as soft start, wherein low voltage low current electricity is passed through the battery.  This prevents overheating of the battery and keeps the internal battery temperature stable and normal.

Stage 3 Bulk Charge

Bulk charge is the third stage for Falcon+ series Su Kam inverters, which is usually the first stage of ordinary inverters. In this stage, Su Kam inverter processor provides full charge in high voltage and pre-define current. The internal temperature of the battery increases slowly but doesn’t overheat.

Stage 4: Absorption

In the absorption stage of a normal inverter, the battery charges slowly because of constant high voltage and decreasing current. The battery gets completely charged but the internal temperature of the battery remains high. In the absorption stage of Falcon+ models, the output voltage is constant while the output current reduces slowly. The last 20% of the battery is charged very slowly to safeguard the battery from overcharging and overheating.

Stage 5: Equalization

Ordinary inverters do no come with equalization stage, but it is an important stage for the new Su Kam inverters considering battery’s long life and efficiency. Now, due to constant use of batteries in frequent power cuts, the electrolyte in the sulphuric acid starts to get concentrated at the bottom. This negatively impacts the battery performance. The mixing of water and sulphuric acid is important for battery’s optimal performance. In Falcon+ series inverter processor gives out the high voltage and constant current supply to the battery. This helps in mixing of sulphuric acid and water properly. In a normal inverter, there is no equalization stage. That is the reason why the water and sulphuric acid does not mix well. This hampers the battery charging process and takes toll on the battery efficiency.

Stage 6: Float

The final stage in the battery charging process is the float stage. Now, the float stage of a normal inverter has continuous battery charging. On account of which the internal temperature of the battery remains high. But in the float stage of Falcon+ series models, inverter processor supplies intermittent electricity called trickle charge. Trickle charge is one in which the battery is supplied with low voltage and low current at a rate nearly equaling to the idle discharge rate of the battery. This way neither the battery overcharges nor the internal temperature shoots up.

Low Voltage Charging to Cater Users Facing Undervoltage Problem

In many rural area and small towns when there is the recurring problem of low voltage supply from the grid, normal inverters start giving problems. Now, the common complaint from the users residing in a low voltage area is that despite the availability of the main supply, their inverter fails to charge the battery and the load in their house does not work on main but from the battery. This results in frequent discharging of the battery.

Let’s try to understand electronics behind this problem. Normally the mains supply available at homes supply the voltage in the range of 220V to 240V. Taking the power from the mains inverter charges the battery. The current supplied to the battery varies with temperature and if the current falls below a certain threshold level, the battery won’t charge properly. Now, in the low voltage areas, input voltage falls to 140V or even lesser. As seen from the chart below, at 140V, a normal inverter charges the battery with 7 amperes of current. If this input voltage reduces to 120V or 110V, a normal inverter charges at 1 amperes or 1.5 amperes. If 120AH or 150AH battery is installed in the house, then this charging current is insufficient to charge the battery.

In fact, below 110V, normal inverter stops detecting the mains and starts working directly on the battery to power the household load. Su-Kam has innovated again in this domain, which would prove a boon for the customers residing in the area where low voltage problem is frequent. Premium UPS models from Su Kam are capable of working even at 90V and able to supply current of 5 amperes. The difference between the supplied current from the ordinary inverter and Su Kam Falcon+ is clearly evident from the chart. Falcon+ only switches to the battery if the input voltage falls terribly low—85V or less.


Su Kam is one of the dominant players when it comes to inverters and USPs and definitely a forerunner in innovation in this domain. That is the reason why Su Kam was the first brand to introduce gamut of technologies like ATC, 6-stage battery charging, plastic body inverters and DSP sinewave inverters. In fact, Su Kam files for 2 patent every month on an average. Su Kam is the only inverter company whose R&D is recognized by the government of India. Though there is not much to criticize about Su Kam inverters, customers have often found them to be noisy. Also, the life of Su Kam batteries isn’t as good as the ones from Exide or Amaron. But leaving these cons, Su Kam is one of the best inverter/UPS brands out there if you want the latest technology with good reliability.

Some Good Sukam Inverters

About the Author:
Hussain Kanchwala is an Electronics Engineer from University of Mumbai. As an Analyst at BijliBachao he keeps a tab on latest technologies in gadgets and appliances, tracks businesses of white goods companies and monitors the consumer behavior. With a background in engineering, penchant for detail, and flair for writing he regularly write reviews about brands and their products. .

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