The most notable difference between lithium iron phosphate and lead acid is the fact that the lithium battery capacity is independent of the discharge rate. The figure below compares the actual capacity as a percentage of the rated capacity of the battery versus the discharge rate as expressed by C (C equals the. Lithium delivers the same amount of power throughout the entire discharge cycle, whereas an SLA's power delivery starts out strong, but. Charging SLA batteries is notoriously slow. In most cyclic applications, you need to have extra SLA batteries available so you can still use your application while the other battery is charging. Cold temperatures can cause significant capacity reduction for all battery chemistries. Knowing this, there are two things to consider when. Lithium's performance is far superior than SLA in high temperature applications. In fact, lithium at 55°C still has twice the cycle life as SLA does at.