Do the increased efficiency and service life of lithium-ion batteries justify their extra cost?
The main disadvantage of lithium-ion batteries is their high upfront cost, which may be 5 times the cost of a lead-acid battery bank of the same rated capacity. However, there are considerable advantages to the technology:
-Service life is 4 times longer... for example a lead-acid battery which is rated for 500 cycles may be replaced by a lithium-ion battery rated at 2000 cycles.
-Lithium-ion batteries have a higher usable capacity: Lead-acid batteries can normally only take 50% depth of discharge, while lithium-ion can work with 80%.
-Lead-acid batteries must be fully charged before being re-used, not the case with lithium-ion cells.
-Lithium-ion cells are much more compact and less heavy, for a given battery bank capacity.
-Lithium-ion batteries are less sensitive to temperature, and can provide their rated amp-hours regardless of rate of discharge... lead-acid cells provide less capacity if the load is high.
-Lead-acid batteries may lose up to 15% of the energy during the charge/discharge cycle (85% efficiency). Lithium-ion cells have an efficiency close to 100%.
In reply to Leonardo David: