Breckland Scientific 2021 Catalogue

Batteries

Breckland Battery Types

a

Standard (non-rechargeable) batteries Available as Zinc chloride (ZnCl), Alkaline or Lithium formats. Equivalent sizes for all formats are interchangeable, but are suitable for slightly different uses. Zinc-chloride (ZnCl) Better than the old zinc carbon type of battery cell but with only about half the capacity of alkaline cells. These are the cheapest batteries to buy, but have the shortest user-life and shelf-life (about 3 years). Suitable for low current drain devices such as radios, toys, hand torches etc. Most commonly available as: 1.5V AAA, AA, C & D types and 9V PP3 & PJ996 types. Alkaline More expensive than ZnCl batteries, but with a higher current output and approx. twice the capacity. They have a longer user-life and longer shelf- life (up to 7 years). Suitable for general use and high drain applications (e.g. cameras). Most commonly available as: 1.5V AAA, AA, C & D types and 9V PP3 type. Lithium Newer technology but more expensive, these have a high current output, a long user- life and low self-discharge during storage – giving a longer shelf life than alkaline batteries (up to 10 years). Most suitable for higher current applications, the output voltage is constant during use. Most commonly available as 1.5V AAA and AA types, 9V PP3 type and 3V coin cells. Button cells Available in alkaline (LR) or silver oxide (SR) formats. If the numbers suffixing the letters of the two types are the same, they are interchangeable (depending on the requirement) as the cells dimensions are the same e.g. an LR44 has the same dimensions as an SR44. Alkaline (LR) button cells During use, the voltage drops below the nominal quicker than with silver oxide cells. They are cheaper than the silver oxide equivalents but have a shorter user-life. These are often known as ‘LR’ types e.g. LR44 and typically have a voltage rating of 1.5V. Silver oxide (SR) button cells During use, these give a steady voltage discharge over a longer period than alkaline button cells, before the voltage drops. They also have a longer user-life than the alkaline equivalents. These are often known as ‘SR’ types e.g. SR54 and typically have a voltage rating of 1.55V.

b

c

d

e

f

g

h

i

j

k

l

m

Coin cells These are generally larger in size than button cells, with a higher voltage rating.

n

Lithium coin cells High energy capacity to mass ratio, with a higher voltage per cell - usual voltage rating is 3V.

o

p

Rechargeable batteries

Nickel Metal Hydride (NiMH) Now the most commonly used type of rechargeable batteries for general use, with little ‘memory effect’. These have mostly replaced the older Nickle Cadmium (NiCad) batteries, which are more toxic to the environment and discharge more readily during storage. NiCad batteries also suffer from a ‘memory effect’, whereby the batteries need to be fully discharged before re-charging or the charging capacity will be reduced. However, NiCad batteries can be re-charged many more times than NiMH types, so have a longer life-span. Voltage rating of NiMH (& NiCad) rechargeable batteries is slightly lower than the equivalent types of non-rechargeable batteries - typically 1.2V instead of 1.5V and 8.4V instead of 9V. Standard NiMH batteries will lose charge during storage, so may need to be re-charged slightly before use. However, ReCyko batteries are a newer type of NiMH rechargeable battery which come supplied fully charged and do not discharge as quickly as standard NiMH types. They should retain up to 85% of their charge when stored for up to a year, whereas standard NiMH batteries can lose 20% or more of their charge within a month or so.

q

r

s

t

v

w

82

www. breckland SCIENTIFIC .co.uk