Can VRLA batteries be used as starting batteries as well?

Discover™ VRLA batteries will work in starting applications as long as the charging voltage is regulated appropriately. Many vehicle regulators are set too high for gel batteries; therefore, the charging system may require adjustment to properly recharge a gel battery for best performance and life. Both Gel and AGM batteries excel as combination cranking / reserve capacity storage batteries. In low temperatures AGM batteries will perform better than Gelled electrolyte batteries. As a general rule, if you are going to use a true deep cycle or traction EV Dry Cell, Advanced AGM, Gel or Flooded battery as a starting battery also, you should increase the reserve capacity of the original battery by between 20% and 30% for use in moderate climates and 30% to 50% for use in colder temperature environments. Modern engines with fuel injection and electronic ignition generally take much less battery power (CCA) to start, however most have larger ampere hour capacity (reserve capacity) requirements to maintain stable and higher voltages as a result of there growing list of accessories and the sensitive voltage requirements of electronic fuel injection systems.

Note that the difference between Gel and AGM batteries for higher current, high power applications is very small until extremely low temperatures are experienced. Please see the section “How does Temperature affect a batteries available Capacity”, later in this document.