Application and costs of rechargeable batteries compared to primary cells

We use batteries everywhere - in almost every toy, in walkmans, discmans, flash units, digital cameras, gameboys etc. Every year, an average of 60 batteries are used in each household, which causes costs of about 75 to 80 $ per year. A more intelligent solution is the use of rechargeable batteries wherever it is possible! For most applications where we use disposable batteries we can make use of rechargeable batteries instead. The cost saving is enormous!
Example: If you take about 1,000 digital photos a year, you spend about 80 Euro on disposable batteries. For the price of two batteries you could also buy one rechargeable battery that can be recharged up to 1000 times.
 

Batteries are the most expensive type of energy.

To be produced they require about 50 to 500 times more energy than they actually provide. Another significant disadvantage of primary batteries is the fact that they cannot be recycled due to technical and economic reasons. However, common NiCd rechargeable batteries can be fully recycled and their raw material can be used for the production of new cells. We can create the all-important advantage for the environment of rechargeable batteries – their long life, by handling them correctly.

Warning - rechargeable battery killer!

Rechargeable cells use different quantities of energy. Therefore, they require different charging currents and supervision during the charging process. Most of the low-priced chargers (which often are available for less than 5 $) do not have protection against reverse polarity. This means the battery can be damaged when it is inserted the wrong way. Moreover, these chargers cannot recognize the charging current required by the rechargeable battery. They are not equipped with charge control. In the best case cells are charged badly, in the worst case they are damaged. Rechargeable batteries charged by poor quality chargers can only be charged 25 to 50 times instead of 1000 times (assuming they are not destroyed by the charger). That’s why those chargers are sheer “battery killers”. High quality chargers are always equipped with protection against reverse polarity, adjust to the requirements of cells and provide them automatically with the right charging current (e.g. the ANSMANN BASIC series). Our professional chargers are fast chargers. They charge even half full batteries and due to their refresh/discharge function they avoid the memory effect of NiCd cells. They save time and are simple to use. Even if cells are inserted at different times, there are no charging problems. These chargers indicate when cells are completely charged and even detect faulty batteries. The trickle charge allows you to leave the batteries in the charger until you need them. Therefore, they are always full and ready to use without losing capacity or being overcharged (e.g. ANSMANN POWERline series).

Tips on how to handle rechargeable batteries

• Batteries should be charged before their first use

• Do not incinerate, short-circuit or open violently

• Always pay attention to correct polarity when inserting the batteries; The symbols on cells for positive and negative polarity always have to correspond to those on the slot where they are inserted.

• In general, both types of rechargeable batteries (NiCd or NiMH cells) can be used. However, we recommend to always use the same type of cells (NiCd or NiMH) with the same capacity (e.g. 600 mAh) during one charging process.

• To avoid a loss of capacity of NiCd batteries (the so-called memory effect) you should discharge the batteries completely every 10th charging cycle.

• The charging time of batteries depends on their nominal capacity (printed on the cell in mAh) and on the charging current. The charging time can be determined as follows: Charging time (h) = battery capacity (mAh) x 1.4 (charging factor)\ charging current of the charger (mA)

• For your information all ANSMANN chargers have a table printed on their back side to indicate the charging time in relation to the charging current and the capacity of the cell. The range of ANSMANN chargers offers an optimum solution for every type of application.

Brief explanation of some common technical terms

Memory effect

The memory effect is a loss of capacity of NiCd cells. When batteries have been over-charged, partly charged or have not been discharged before fast charging they cannot maintain and provide their full power. As a result, they provide less and less capacity after only a short operating time. ANSMANN chargers with optional discharge feature allow you to completely discharge batteries before starting the next fast charging process. We only notice the memory effect with NiCd cylindrical cells. 9V battery blocks are composed by several button cells that do not have the memory effect. Therefore, discharging 9V batteries is not necessary.

Nominal capacity

When we talk about the nominal capacity (mAh) of a battery we refer to the capacity given by the manufacturer. The higher the nominal capacity of a cell, the longer the operating time of the appliance it is used in (e.g. operating time of a discman using 600mAh cells: 2 hours; using 1500mAh cells: 5 hours).

Self-discharging

Here, we are talking about the loss of capacity of a charged cell while it is stored and not in use.

Automatic matching of charging current

The particular construction of the V-shaped charging slots and different contacts on the positive pole guarantee that each rechargeable battery is provided with the optimum charging current.

Floating charge/trickle charge

Floating or trickle charge means that the charger maintains a low charging current to avoid self-discharging of the cells. This function makes sure that fully charged batteries can be left in the charger after the fast charging process until they are needed. Thus, they are always full and ready to be used without being overcharged or losing capacity.

Alkaline Cells

These are your Duracell type. They are non-rechargeable, and have difficulty providing the large currents demanded by digital devices like digital cameras / GPS systems / minidiscs etc. However, they do have a surprisingly large energy capacity, perhaps 2500mAh. They are best suited for use in low drain applications (doorbells, TV remote controls etc.) because their shelf life is so long. In other words, they do not self discharge to any appreciable extent when not in use. They are not really suitable for use in digital cameras except in emergencies. Cell voltage: 1.5V.

Lithium Batteries, or Lithium Photo Batteries

Lithium batteries are non-rechargeable, and an entirely different technology to Lithium Ion batteries which are rechargeable. They have many of the characteristics of alkaline cells, with a large energy capacity, and very long shelf-life. Cell voltage: 1.5V

Li-Ion Batteries (Lithium Ion)

Rechargeable, suitable for high current drains, and with a very high energy capacity for their size and weight, many cameras accept a Li-ion battery. They are often flat or rectangular in shape. Disadvantages are high cost, and some evidence to suggest their performance gradually degrades. A range of battery voltages are available.

NiMH Batteries (Nickel Metal Hydride)

Rechargeable, non-toxic, very high capacity, no memory effect and able to deliver large currents. Like NiCADs they have one disadvantage, and that is they slowly self-discharge even when not in use. So they are not the ideal choice for very low current drain devices (remote controls, clocks, doorbells etc.) However, for high power devices like digital cameras they are the ideal option.

NiCAD Batteries (Nickel-Cadmium cells)

Rechargeable forerunners to NiMH batteries, they have a number of disadvantages. They suffer a memory effect which means that their performance can decline with use, and their energy capacity is lower than the more recent NiMH cells. A particularly serious problem with NiCAD cells is their incorporation of Cadmium. A yellow metallic element - Cadmium is extremely toxic and its use in yellow paint was banned many years ago. For this reason NiCAD battery technology has itself been banned in a number of countries. Cell voltage is 1.2V, the same as NiMH cells, so the good news is that NiCADs can virtually always be replaced with a similar NiMH cell. Arguably one of the least environmentally-friendly items on the market, you will not find any NiCAD cells on the WPS site!