12V sealed lead-acid battery specs

Discussion in 'General Electronics Chat' started by argon, Dec 20, 2009.

  1. argon

    Thread Starter New Member

    Dec 3, 2008
    12V sealed lead-acid batteries are marked like this:

    constant voltage charge
    cycle use: 14.4 - 15 V
    standby use: 13.5 - 13.8 V
    initial current: less than 2.7 A

    I take these to mean:
    1. charge at 14.4 - 15 V if used until drained;
    2. charge at 13.4 V - 13.8 V if used but not drained;
    am I correct? What does "initial current" mean? Thanks in advance.
  2. SgtWookie


    Jul 17, 2007
    It is best to find a datasheet for the particular battery in question to determine recommended rates for optimal battery life.

    There are several phases to charging a lead-acid battery.
    1) Bulk charge: this is when the battery has been depleted more than 20% or so. The battery is charged at a constant current (the "initial current") until the voltage reaches a predetermined level.

    2) Absorption charge: The battery is charged at a set voltage (less than the bulk charge termination threshold) until the charge current decreases to a predetermined level. Some simple chargers only use this mode of charging.

    3) Float charge: The battery is charged at a voltage in the range of the "standby use" you mentioned. It is best for the life of the battery if the charge voltage is adjusted according to the battery internal temperature. The temperature can be measured from the positive terminal.