2. Nickel-metal-hydride- NiMH
The scientists began researching for this in 1967, though there were some volatilities with the metal-hydride, which compelled the scientists to develop the NiMH, Nickel-hydrogen battery. The NiMH is commonly used to power the satellites.
The scientists discovered a new metal-hydride in the 80s, which was more stable and this made the NiMH to advance gradually. Currently, the NiMH offers 40% more energy compared to a typical NiCd battery. In addition, the NiMH has no toxic metals in the.
There has been an advancement of the Nickel-metal-hydride battery, which has twice the energy of the previous version, and the durability has been prolonged as well. However, lithium-ion became more popular and it slightly reduced the NiMH interest. Nevertheless, the makers of Hybrid Electric Vehicles haven’t stopped using the NiMH technology. The NiMH batteries are chosen over the Lithium-ion as they are cheaper and safer. It is claimed that the NiMH batteries are about a third of a corresponding Li-ion battery.
Disadvantages of NiMH
• Low energy. They have lower energy emission compared to the Lithium-ion batteries, for this, they can only be used or consumer products and not for HEVs.
• High self-discharge. They will lose up to 20 of its charge in just 24 hours, which can be very inconvenient. For that, you might be needed to charge it constantly.
The NMH can be customized to lower the self-discharge feature and the allow corrosion, but the specific energy will be reduced. Though they are readily available for use, they have a lower voltage compared to the Lithium-ion batteries.
Use Of NiMH Batteries For Consumers
They are readily available and they are cheap to recharge, especially for mobile devices. Since they are non-toxic, they can offer a high energy compared to the NiCd. The batteries come in various sizes of AAA and AA, from top battery manufacturers. They are easily rechargeable and they are the most recommended, for the sake of environmental friendliness.
They have been used as a replacement of the reusable alkaline batteries that were used in the 90s, which had poor loading features and restricted cycle life. However, the only concern of the Nickel-based batteries is that they are self-discharging, which will drain slowly, whether in use or not.
If you have a mobile media player or a flashlight that uses NiHM batteries, they will end up running out within a few days or weeks. For instance, the Eneloop NiHM battery by Sanyo has cut down the self-discharge by about 6, which means that you can store the battery for a longer period of 6 times, compared to a standard NiMH.
Advantages Of Industrial Use NiMH Batteries
• Higher capacity. They have a capacity of 30 to 40% higher than the typical NiCd.
• Less Memory effect: They are less susceptible to memory, compared to NiCd batteries.
• Easy to store and transport.
• They are friendly to the environment as they don’t have toxic metals.
• They contain Nickel, which benefits the recycling aspect.
• Reduced Service life. Since they are self-discharging, the service life is reduced as well.
• They need a sophisticated charge algorithm in order to charge them effectively.
• They will not absorb the overcharge perfectly, for that, the trickle charge will be expected to be less.
• When they are under high-load discharge and fast-charge, they will generate a lot of heat.
• They are self-discharge, for that, they will lose more power when not in use.
• It needs to be stored in appropriate temperatures.
Generally, the Nickel-based batteries tend to be more reliable, despite their self-discharging aspect. Their safety and affordability is what makes them be many manufacturers preference.