Author: Martin Hillier
Battery Voltage Codes ========= ========= =================================== N 1.5V UM5, Lady AAA 1.5V HP16, UM4, LRO3, MN2400, Micro AA 1.5V HP7, UM3, LR6, MN1500, Mignon C 1.5V HP11, UM2, LR14, MN1400, Baby D 1.5V HP2, UM1, LR20, MN1300, Mono PP3 9.0V 6F22, E-Block, MN1604, 1604, 006P, 6R61, Neda
Type > Zinc Carbon Zinc Chloride Alkaline Magnesium Size ==== ============= ============== =================== N 0.5 AAA 0.54 0.7 AA 0.9 1.1 2.3 C 1.8 2.8 7 D 5.2 7.5 14 PP3 0.3 0.4 0.5 Type > Standard Industrial Nickel Metal Size Ni-Cad Ni-Cad Hydride ==== ============= ============== =================== N 0.15 AAA 0.22 AA 0.5 0.85 1.2 C 1.6 2.0 D 1.2 4.0 PP3 0.12
There internal resistance is quite high and can not supply much current, they have a high shelf life and also decay when used. As the Zinc can is also the anode, they are prone to leaking if the Zinc fails to oxidise evenly. Leaking can also occur if they are over discharged.
They are best suited to low power applications with intermittent use, say a small radio for an hour or so a day. Zinc Carbon needs frequent rests to recover and are not suitable for continuous use. Don't use these cells in expensive equipment or leave them in equipment for long times, because of the risk of leakage. Stand-By applications and wide temperature ranges should also be avoided.
They tend to have lower internal resistance and higher capacities, allowing higher currents to be drawn for longer periods. The longer shelf life is a major factor in buying these cells.
Zinc Chloride cells are suited to moderate intermediate use, as in cycle lights where performance is close to Alkaline cells. They work well with lower power applications such a clocks, although they are not suited to Stand-By usage where they will be unused for long lengths of time.
The Alkaline Potassium Hydroxide electrolyte rather than the acidic electrolyte in Zinc cells gives them there name.
There low internal resistances gives higher performance, in applications such a camera flashlights where Zinc cell don't work. The components are enclosed within a separate steel can, giving good leak resistance.
The key to Alkaline tests is the continuous nature, the high power and heavy use is needed to get the most out of these cells, in intermittent low power applications they only give about 2 to 3 times the capacity of Zinc Carbon. These cells don't work well in continuous low power applications.
They are ideal for low drain applications such as smoke alarms and data retention. The high price is justified with a very long life.
The basic voltage for Ni-Cads is 1.2V which makes them unsuitable for certain applications. The number of times they can be recharged is also limited, bad charging habits reduce this even more.
They do have fantastically low internal resistance which gives very high currents, this can also come in useful for starting fires.
The main problem with Ni-Cads is the dendrite growths, miniature metal spikes which eventually short circuit the cell. This can be reduced by PCR charging.
Because there is no Cadmium in the formulation, there is no memory effect and is useful in plug in rechargeable tools and lights.
When ever possible use mains adapters, its 5000 times cheaper than batteries.