Batteries 101

Batteries 1012019-10-22T15:14:58+02:00

Energizer Premium Car Battery

Batteries 101- Battery Care from Battery Powerzone

  • Never store a battery in a discharged state.
  • Always recharge your battery after use, especially if it is going to be stored.
  • A fully charged battery should measure 12.7 – 12.8 Volts (when disconnected from the charger).
  • At 12.0 Volts, a battery has lost 60% of its capacity and is considered discharged.
  • Always ensure that the battery capacity is sufficient for the application.
  • Always use the battery for the application for which it was designed.
  • Battery application categories may be loosely classified as follows: automotive, deep cycle, uninterruptible power supply, traction, motive power, renewable energy.
  • For greater life expectancy, do not use automotive batteries in cyclic applications.


  1. Corrosion on battery posts may be removed with a solution of bicarbonate of soda and warm water.
  2. Vented batteries (with filler caps) need to be checked periodically for water levels.
  3. Only top up with de-ionised (distilled) water. It is not advisable to use tap water.
  4. Batteries may need to be given a refresher charge from time to time – especially leisure batteries used in e.g. caravan, boats, motorcycles, jet skis, etc.
  5. Battery voltage should never drop below 12.2 V when being stored.
  6. Most modern design batteries, especially sealed batteries require careful charging.
  7. It is advisable to use ‘intelligent’ three-stage or multi-stage chargers.
  8. Ensure that your battery is held down firmly. Vibration is a battery killer.
  9. Wet acid batteries in stationary applications may be shaken from time to time to facilitate electrolyte mixing which can enhance the life of the battery.


  • The CCA (cold cranking amp) rating on a battery indicates the amps that can be drawn from the battery at minus 18 degrees Celsius continuously for thirty seconds to an end point voltage of 10.5 Volts.
  • The CA (cranking amp) rating on a battery indicates the amps that can be drawn from the battery at zero degrees Celsius continuously for thirty seconds to an endpoint voltage of 10.5 Volts.
  • Reserve capacity indicates the time in minutes that a battery can deliver a load of 25 amps continuously to an endpoint voltage of 10.5 Volts.
  • RECHARGING batteries in an AUTOMOTIVE application – a battery in a 12 Volt vehicle needs to be recharged at a rate of 13.8 – 14.3 Volts. Anything outside this window needs to be checked.
  • RECHARGING batteries with EXTERNAL chargers requires specialised consideration, particularly with sealed batteries.
  • Recharge discharged batteries at a rate of 10% of the rated capacity of the battery as minimum
    (e.g. a 100ah battery should be recharged at a minimum of 10 amps)
  • Flooded (wet – including sealed) batteries require 8 – 16.0 Volts in the equalisation / absorption stage of charging
  • AGM (absorbed glass mat) batteries require 14.7 Volts in the absorption stage charging.
  • GEL batteries require 14.4 Volts in the absorption stage charging.
  • A battery is load tested at three times its ampere hour capacity.
  • The battery must hold this load for 15 seconds and the voltage should not drop below 9.3 Volts.
  • Batteries may be left permanently connected to an intelligent charger at a float (trickle) voltage not exceeding 13.6 – 13.8 Volts.

Need a battery? Battery Powerzone can help. Stop by at any of our outlets where our friendly team will assist you.