There are pros and cons associated with the two main battery chemistries used in solar + storage projects. Lead-acid batteries have been around much longer and are more easily understood but have limits to their storage capacity. Lithium-ion batteries have longer cycle lives and are lighter in weight but inherently more expensive.
Storage installations typically consist of one battery type, like with LG Chem, here. Can one combine the pros of each chemistry to make one cost-effective, high-capacity battery bank?
Does one have to dismantle their lead-acid battery bank just to tap into the functions of a new lithium-ion battery? Can one add a few cheaper lead-acid batteries to their lithium system to meet a certain kilowatt-hour capacity?
All important questions with a less defined answer: it depends. It is easier and less risky to stick with one chemistry, but there are some workarounds.
Read more: SolarPowerWorld