Selection Criteria for Diesel Cranking Batteries

Selection of batteries for starting of diesel engines comprises both the choice of an appropriate battery type and a correct size, having in mind that economy and reliability should be considered along with technical performance. The power requirements for starting depend i.a. on motor size, required cranking speed, motor oil grade and temperature. The influence of these factors on the battery demands are discussed, and simple design relationships are derived. Having established the appropriate selection criteria in view of engine specifications and environmental conditions, the most common cranking battery types are discussed. Each type is assigned a figure of merit, taking price, performance and life expectancy into account. It is concluded that lead-acid batteries with tubular positive plates offer the best economy, except under extreme environmental conditions.