Decline in price hikes demand for Li-ion batteries

While nickel based ready to use rechargeable batteries are new entrants in India, some of its new types are yet to be launched in India

Monday, November 12, 2012: Small, rechargeable battery market is dominated by breakthroughs in battery chemistries; systems integration for mobile, portable and stationary applications; reliability, energy efficiency and safety factors. Rechargeable batteries are used in countless applications including remote controls, cordless phones, mobile phones, power tools, iPods, laptops, toys, handheld games, digital cameras, flashlights, etc.

The most commonly used rechargeable batteries include lithium-ion (Li-ion), lithium polymer (Li-ion polymer), nickel cadmium (NiCd) and nickel metal-hydride (NiMH). Can these batteries ride on all the new trends or does the future lie beyond these batteries?

What’s new in the market

Various forms of lithium batteries are emerging in the market. This trend is because lithium is more eco-friendly than lead or cadmium. Lithium is the lightest metal and leads to a high specific charge. For example, it takes 3.85 g of lead to produce 1 amp for 1 hour while it only takes 0.26 g of lithium to produce the same power. Lithium also produces a higher voltage and, therefore, a higher energy density. Almost all major players in the industry including Uniross, Prime Products, Evolute, Kandhari Photo Electronics, Panasonic, Samsung and LG offer lithium batteries.

As lithium batteries have a wide range of applications and are more in demand, the current trend reflects a decline in prices, particularly of lithium polymer, which has fallen by 10-20 per cent in the past two years.

Lithium-ion (Li-ion) batteries are still most widely used, especially in devices like smartphones, digital cameras, compact DVDs, CD players, etc. These batteries offer 3.7 V with high capacities. While Li-ion batteries have many variants, the most popular ones are nickel cobalt manganese (NCM), lithium iron phosphate (LiFePO4 or LFP) and cobalt oxide.

One new type of Li-ion battery is currently being offered by Evolute Solutions Pvt Ltd, which is a multi-cell Li-ion battery pack and comes with a battery management and protection circuit. “The life and performance of the Li-ion battery pack depends on the battery management circuit. Without proper protection or management, Li-ion cells are potential bombs. There have been a lot of instances in the past where poor or faulty protection has resulted in the exploding or burning of consumer equipment that have even caused injuries to users,” informs Manoj Pawar, regional manager sales, Evolute Solutions Pvt Ltd.

Montu Electronics has also designed a light weight and advanced Li-ion battery. These are good for smartphones, iPads and Bluetooth enabled devices. “It is a single Li-ion cell with very high capacity and is much safer than the others in the market,” claims SS Kandhari, partner, Montu Electronics.

Li-ion batteries offered by Uniross can be used in cameras, iPods and iPads. “These batteries offer a 12 hour power bank in comparison to other conventional batteries, which only offer up to eight hours of backup. They are high on quality with a long life expectancy and low cell discharge, and come at a price of Rs 3600,” informs Sushil Kumar Varshney, director, Yo! Digitals, a distributor of Uniross.

Toshiba Corporation claims to have made a breakthrough in Li-ion batteries. Its new battery can recharge up to 80 per cent in about one minute, approximately 60 times faster than the typical Li-ion batteries. The battery also has a long life cycle, losing only 1 per cent of capacity after 1000 cycles of discharging and recharging, and can operate at very low temperatures.

Lithium iron phosphate (LFP) batteries are one of the latest entries in the market, and have become quite popular, as these are more sturdy and can work at comparatively higher temperatures and in adverse climatic conditions. They have a nominal voltage of 3.2 V where normal AA, AAA and alkaline batteries offer 1.2 V to 1.5 V. They also offer a longer life—from 1000-2000 charge/discharge cycles, while sealed lead acid (SLA) batteries have only 300 cycles and NiMH batteries have 300-500 cycles. LFP batteries weigh less than SLA and NiMH batteries, and are safer as they are stable in high temperatures and never explode. LFP batteries are used for electric power tools, electric bicycles, electric scooters, solar lamps, LED lighting, etc. Though there is a good demand for these batteries, they are not manufactured in India, but only imported, processed and assembled in India. Players like Sealed Energy Systems, Lotus Energy and Avni Electrosoft offer these batteries.

Some other new types of lithium batteries seen in the market are the tri-element cells of nickel, cobalt and manganese, called NCM and cobalt oxide batteries. The former are commonly used as they are lower in cost without compromising on energy density. These batteries have slightly lower voltages, and since they have the lowest self heating rate, they are preferred for electric vehicles.

Due to their high specific energy make, cobalt oxide batteries are a popular choice for cellphones, digital cameras and laptops. These batteries have a shorter life span but can handle load capacities.

Lithium polymer batteries are the latest advancement in the Li-ion domain. These are in good demand and their biggest advantage is that they are smaller in size yet higher in capacity. For example, in a mobile phone where Li-ion batteries would fall within the range of 1000 mAh to 1200 mAh, lithium polymer batteries offer a capacity ranging from 2000-3000 mAh. These batteries have a better energy density than that of other Li-ion batteries and can be discharged at a higher current without affecting the life of the battery or causing any kind of internal damage to it. Mostly, these batteries are being imported from China, though players like Evolute and Montu Electronics also manufacture battery packs from the Li-poly cells.

Nickel based batteries: Nickel zinc (Ni-Zn) batteries are a new type of rechargeable battery available abroad. They are environmentally safe, and have an upgraded combination of Ni-Mg, alkaline and Ni-Cd batteries. A single cell of Ni-Zn has 1.6 V and offers advanced features in comparison to other batteries. It is also the perfect combination of a higher voltage offered by alkaline batteries, the high current discharge features of Ni-Cd batteries with pollution free feature of Ni-MH batteries. Ni-Zn is used in digital cameras, shavers, electric toys, electric tools, electric bicycles, etc.

According to Abhinav Gupta, manager, marketing and applications Sealed Energy Systems, this product has still not entered the Indian market. “NiZn has zinc anode which is not stable for cycle use. Due to dendrite growth, the cell loses its capacity and voltage while in usage. DRDO did not approve this technology,” says Abhinav Gupta.

“Besides, since these batteries have low cycles, their life stability is very poor and hence they are commercially not viable,” he adds.

The ready to use, rechargeable and refined versions of NiCd and NiMH batteries are also new types of batteries. These are more advanced because of their low self-discharge characteristics. Unlike previous rechargeable batteries, which have a limited shelf life (a fully charged normal NiMH battery drains out in about 30 to 45 days even when not in use) because of their rapid discharge, these batteries retain 80 per cent of their charge even after one year. As these batteries can be used for thousands of charges and are easily recycled, they are much more convenient, cost effective and ecofriendly than the traditional single use batteries.

Under this category, Sanyo has introduced Eneloop, which is a rechargeable NiMH battery. Sanyo Eneloop rechargeable batteries come pre-charged and ready to use. This battery self-discharges extremely slowly in storage, so even after three years, it is still 75 per cent charged. This is also extremely cost effective as it can be charged 1500 times. However, some users believe that these batteries have a lower capacity than others, and work best with the Sanyo charger only.

IMS Mercantiles has also launched such ready to use rechargeable batteries. “Its AA 2500 mAh Envie Infinite Plus batteries and the AAA 1100 mAh Envie Infinite Plus batteries have been rated as the No. 1 rechargable batteries in their respective category by Asian Photography maagazine. “These have highest capacity in their category of rechargeable batteries in the India market,” claims Amit Saraf, managing director, IMS Mercantiles Pvt Ltd. Under its brand Digitek, the company manufactures lithium batteries and power banks made up of Li-ion cells.

Duracell also offers NiMH rechargeable batteries, which are ideally suited for high drain or frequently used devices. These are available in AA and AAA sizes. These batteries can be charged hundreds of times, and are best for video game controllers and high powered flashlights. With low self discharge, Montu Electronics has also introduced DIGICAM AA 2400mAh battery in April 2012. This AA2400mAh is an NiMH ready to use rechargeable battery that gives good performance and longer life cycle.

Eveready has come up with the Eveready Recharge, which is designed to deliver optimal performance. Its high end batteries come with an intelligent charger that includes various capacity ranges.

How to choose the right battery

While making a purchase decision, a buyer should be aware about the characteristics of the various kinds of batteries available in the market, and also about the nature of the equipment these batteries will be used for.

Nature of application: According to Amit Saraf, a battery should be selected based on the nature of the device it will be fitted into and the duration of its usage. “For example, for applications like clocks or remote controls, high capacity rechargeable batteries will be a failure as compared with the zinc carbon or alkaline batteries, unless ready to use rechargeable batteries with low self-discharge characteristics are being used,” he says. However, in high drain applications like digital cameras or MP3 players, rechargeable batteries are a boon as alkaline batteries will only last a short period, increasing the cost of the replacement battery.

Nature of the battery: Another point to consider is the nature of the battery—its charge/discharge rate, voltage and capacity.

It is also important to consider whether a battery has high/low self-discharge or high/low heating. “If it is low drain equipment, which means battery usage in the device is low, a low capacity battery can be used. However, where more power is required, batteries that are sturdier and have low self-discharge should be used,” explains Manoj Pawar. Also, the capacity of the current at which the battery will be discharged and the de-rating of battery at that current, should be checked.

The amount of voltage required to operate an application is equally important to consider. “Applications using more than 4 AA or AAA batteries may not work well with rechargeable batteries because of the voltage factor—alkaline batteries have 1.5 V while rechargeable batteries have 1.2 V. When in use, the voltage of rechargeable batteries drops faster than the alkaline batteries, causing a mismatch between the voltage requirements and the supply, in certain applications,” says Amit Saraf.

Another important feature to consider is the capacity of a battery—how long does one want to run the device? “For example, for a digital camera where you take 500 pictures with one recharge, one should consider batteries with high capacity,” suggests SS Kandhari.

“Besides the above aspects, we also suggest that a buyer opts for environmental friendly batteries like Ni-MH, Li-ion, LFP or Ni-Zn rather than going for lead acid and NiCd batteries,” adds Kandhari.

Some other factors to consider are the operating conditions of the batteries like the temperature, as batteries tend to perform differently at different temperatures. The desired lifecycle of a battery for a particular application should also be looked into.

Electronics Bazaar, South Asia’s No.1 Electronics B2B magazine