safety   precautions   for   the   following   six   types   of batteries ETs are most likely to see: 1.  Carbon-zinc 2.  Manganese-dioxide  alkaline-zinc 3.   Mercuric-oxide 4.  Lithium 5.  Lead-acid 6.   Nickel-cadmium Carbon-Zinc Dry Cell Battery This is a very common battery in the Navy. It has a zinc outer container, a carbon center electrode, and a chemical paste for the electrolyte. It is usually sealed in a  cardboard  or  plastic  casing. There   are   three   important   safety   precautions concerning using, storing, or disposing of carbon-zinc batteries: 1. Do Not store carbon-zinc batteries in electronic equipment for extended periods. The corrosive electrolyte  could  leak  out  of  the  battery  and damage the equipment. 2. Do Not throw carbon-zinc batteries into a fire; they  could  explode.  Keep  them  away  from incinerators. 3. Do Not throw  carbon-zinc  batteries  overboard while   at   sea.   These   batteries   contain   metal pollutants.  Store  them  on  board  (in  a  steel container)  until  you  can  properly  dispose  of them  ashore. Manganese-Dioxide Alkaline-Zinc Cell Battery Commonly called an  alkaline battery, this type of battery is similar to the carbon-zinc battery. The only difference is the type of electrolyte used. You’ll find these  batteries  in  portable  electronic  equipment.  The safety precautions for alkaline batteries are identical to the safety precautions for carbon-zinc batteries. Mercuric-Oxide Zinc Cell Batteries Commonly  called  mercury cells,  these  batteries  are small and powerful. They have longer shelf life than the two previous types of batteries. They were first used to power  miniature  equipments  of  the  space  program. Today  these  batteries  are  used  in  electronic  test 2-6 equipment, cameras, hearing aids, periscope cameras, missiles, cryptographic equipment, and sonar devices. Mercury cells are safe when used properly. But, if they’re misused, BOOM!, they could explode. Use the following safety precautions for mercury batteries: 1 . 2 . 3 . 4 . 5 . Do  Not  place   a   direct   “short   circuit”   on   a mercury cell. Do Not discharge a mercury cell after its voltage falls  below  70  percent  of  its  original  voltage,  or after it fails to operate the equipment it is in. Do Not  leave  the  battery  switch  on  when  the equipment  isn’t  in  use,  or  after  the  mercury  cell fails to operate the equipment. Do Not expose  mercury  cells  to  temperatures over 400 degrees Fahrenheit. Do Not keep exhausted mercury cells. Discard them as soon as possible. If you’re at sea, store them  temporarily  under  water  in  a  steel container until you can dispose of them properly ashore.  When  you  store  exhausted  mercury cells, never purposely puncture their jackets. Lithium Cell Batteries Lithium  batteries  are  high-energy,  long-lasting  bat- teries with a longer shelf life than most other batteries. They are making their way into electronic equipments. They’re used in computers, communications and cryp- tographic equipments, torpedoes, and missiles. Unfor- tunately,   lithium   batteries   can   be   very   dangerous. They’ve  been  known  to  release  toxic  gases  or  to  ex- plode. If you handle lithium batteries, observe the fol- lowing safety precautions to prevent injury to yourself and damage to your equipment: 1 . 2 . 3 . 4 . 5 . 6 . Use only lithium batteries that are approved for use in your equipment. Store them in  cool,  well-ventilated  areas  away from flammable items. Always   observe   polarity   when  you  install them. Do Not  pierce,  short-circuit,  recharge,  crush, cut,  burn,  drop,  dismantle,  modify,  or  otherwise carelessly handle them. Do Not leave them in equipment that won’t be used  for  long  periods. Do  Not  throw  them  away  with  daily  trash. Dispose   of   them   properly.   See   the