Numerous strategies have been developed over the years to deal with the various dynamics of Lead-Acid batteries, from equalization charges to maintain cell health, to overcharge to recover lost capacity due to partial state of charge operation, all the way to pulse charging in an attempt to wake up underperforming cells.
Lithium Iron Phosphate (LFP) Batteries, however are an entirely different chemical battery, and don't suffer the same issues that the lead-acid predecessors do. What are the lifetime and performance considerations for these new batteries, and how can we ensure they last as long as possible?
The best way is to keep the batteries cool, at a standard temperature of 10-35°C and keep the charge and discharge currents as low was possible, or below the C/2 rate.
One of the most important ways LFP batteries age is as a result of temperature. Cold batteries, will wear quickly, as a result of lithium ions moving to the anode at a faster rate than they can be intercalated, causing a buildup of lithium ions as they "wait" to be intercalated. This buildup of excess lithium, which can happen rapidly while charging at low temperatures, will lead to elemental (raw) lithium plating to the surface of the anode and a loss of capacity. The BMS internal to Rolls LFP batteries will keep the batteries from experiencing to worst of these plating issues for cells charged below 0°C, however the charge current must be reduced as batteries approach 0°C as well. Charging batteries at 1C, for example, as they approach 5°C can cause accelerated battery wear. If batteries cannot be kept at temperature in your installation, a proactive approach to limit charge current when temperatures are low is recommended.
Cycling at high temperatures can also cause wear. Over time, batteries cycled (and stored) at an elevated temperature will wear more quickly, as parasitic reactions within all batteries happen at an increased rate with increased temperature. For this reason, it is recommended that all battery installations allow for adequate airflow during operation, and that the ambient temperature is within the range of 10-35°C. Storage temperatures above 60°C will also cause increased wear, and will result in batteries which discharge quicker while not in use. One of the merits of LFP batteries compared to other lithium-ion battery chemistries is in terms of safety. Thermal runaway events are exceptionally rare for LFP unless the battery is at a highly elevated temperature well beyond what the BMS will allow.
Leaving batteries at an elevated (but safe) charge voltage can also cause increased wear, as the increased voltage potential between the anode and cathode will lead to higher rates of parasitic reactions. A CC/CV (2-Stage) charge with a current-based endpoint is thus recommended, with no elevated float voltage, or equalization for Rolls LFP Batteries.