Ni-MH and Ni-Cd rechargeable batteries - basic data (voltages, sizes, specifications)

Ni-MH battery voltage table

Model symbol	specification
	tension [V]	height [mm]	Diameter / Dimensions [mm]
R03 (AAA)	1,2	44,5	10,5
R6 (AA)	1,2	50,5	14,5
R14 (C)	1,2	50	26,2
R20 (D)	1,2	61,5	34,2
6F22 (9V)	8,4	48,5	26.5 x 13.1

Basic facts about Ni-MH rechargeable batteries:

• Anode: An alloy of rare earth or nickel with many other metals
• Cathode: Nickel Hydrogen Peroxide
• Electrolyte: potassium hydroxide
• Applications: Mobile phones, video cameras, emergency lighting, power tools, laptops, portable devices with high power consumption

Ni-MH batteries have replaced older Ni-Cd batteries

Apart from the anode, the design of Ni-MH rechargeable batteries does not differ in principle from the design of older Ni-Cd batteries, which they displaced. Even the voltage (1.2V per cell) is identical, which means that these batteries can be used interchangeably in many applications.
Compared to Ni-Cd batteries, Ni-MH batteries achieve about 30% more capacity, they are also characterized by higher energy density (theoretically 50%, in practice - about 25%). Basic characteristics of Ni-Cd batteries:

• Anode: cadmium
• cathode: Ni(OH)2
• electrolyte: KOH

The anode is nickel-plated, while the cathode is cadmium-plated. The use of cadmium was the main reason for the withdrawal of Ni-Cd batteries from retail circulation.

The electrolyte (KOH) serves only as a conductor of ions and is not involved in the chemical reactions that take place inside the cell. For this reason, more electrolyte is unnecessary, which reduces the weight of the cells. Sometimes, NaOH was used as an electrolyte instead of KOH - it does not conduct ions as well, but has a much lower tendency to cause leaks.

Ni-Cd rechargeable batteries had good performance in applications requiring higher currents and/or low temperatures, long service life and storage time, as well as longer self-discharge times than (standard) Ni-MH batteries.

New generation Ni-MH rechargeable batteries

All cells (batteries and rechargeable batteries) discharge themselves over time, even when they are not in use. In conventional hydride batteries, this effect is clearly visible. By optimising the rechargeable cell technology, Sanyo has achieved great success in minimising the self-discharge effect of ENELOOP batteries.

The chemical decomposition of the cathode was significantly reduced by the use of a new "superlattice" alloy. An additional benefit of the "superlattice" alloy is that it increases the electrical capacity of the battery and reduces internal resistance, which allows for higher discharge currents. Another advantage of the "superlattice" alloy is the lower demand of cobalt to stabilize the structure of the compounds. The anode, on the other hand, was reinforced by the use of a new material, which reduced natural disaggregation. In addition, the separator and electrolyte have been optimized for low self-discharge.

The ENELOOP rechargeable battery is a technology that ensures optimal use of energy even over long periods of time: after 5 years, 70% of the recharged energy remains at the user's disposal. That's why ENELOOP is the first rechargeable battery that comes pre-charged and ready to use the moment you buy it. ENELOOP can be used in exactly the same way as a traditional al batteryimmediately after purchase. Even in low-power devices, where the self-discharge effect of rechargeable batteries was a problem, such as TV remotes, alarm clocks or flashlights.

This is certainly the biggest advantage of ENELOOP over disposable batteries: it can be recharged 1800 times and then easily recycled. As a result, it turns out that this technology is not only more economical, but also allows us to avoid the troublesome recycling of 1800 batteries.

We encourage you to read our article: What are the differences between a 1.2V Ni-MH rechargeable battery and a 1.5V alkaline battery?

New generation rechargeable batteries from other leading manufacturers:

• Energizer Extreme
• Duracell StayCharged
• GP ReCyko
• Varta Ready2Use
• Panasonic Evolta

Read more about the new generation of Ni-MH rechargeable batteries

Our offer: Ni-MH rechargeable batteries

Copyright © Baltrade