Lead Acid Battery Intermittent Charge Algorithm

This algorithm is reviewed in [1]. The battery is charged to the gassing voltage as for ICC and then allowed to rest until the terminal voltage falls to a value  

This algorithm was introduced [1] to avoid the effects of overcharging that occur in the three phase algorithm. This is important to reduce water loss in sealed batteries.

  • It begins with a full limited current bulk charge of the battery until the gassing voltage is reached.
  • Then begins a rest period until the terminal voltage falls to a preset lower limit equivalent to about 97% SoC.
  • The cycle is then repeated until the period of the cycles becomes constant.
The algorithm is reported to leave the battery slightly undercharged and therefore subject to sulphation. Detecting the end-of-charge point is problematic.

As an alternative to the rather unreliable end-point detection, the end point can be taken to be the point at which the average current measured during charge-rest cycle falls to 5% of the battery capacity/hours.

An advantage of this algorithm is that the charger can be utilised for other batteries during the rest phases of the other batteries.


  1. "Charge regimes for valve-regulated lead-acid batteries: Performance overview inclusive of temperature compensation." Y.S. Wong, W.G. Hurley, W.H. Wölfle. Journal of Power Sources 183 (2008) 783–791.
  2. "Charging Algorithms for Increasing Lead Acid Battery Cycle Life for Electric Vehicles." Matthew A. Keyser, Ahmad Pesaran, Mark M. Mihalic, Bob Nelson, 17 Electric Vehicle Symposium Montreal, CANADAOctober 16-18, 2000
  3. "Pulsed-current charging of lead/acid batteries - a possible means for overcoming premature capacity loss?" L.T. Lam *, H. Ozgun, O.V. Lim, J.A. Hamilton, L.H. Vu, D.G. Vella, D.A.J. Rand, Journal of Power Sources 53 (1995) 215-228.
  4. “Mathematical modeling of current-interrupt and pulse operation of valve-regulated lead acid cells,” V. Srinivasan, G. Q. Wang, and C. Y. Wang, J. Electrochem. Soc. 150, A316–A325, 2003.

First created
13 October 2014
Last Modified 13 October 2014
© Ken Sarkies 2014