Since most of my installations involve flooded lead acid batteries I can truthfully say they are not only the weakest link in a solar electric system but the most toxic component I handle as well. Even the most responsible and well disciplined system owner will neglect their batteries many times in their life whether the cause is failing to add the required distilled water to keep the battery's plates covered or making sure the battery stays well replenished within suggested states of charge that promote battery longevity. Traditional flooded lead acid batteries require sophisticated charging regimens and sampling of the caustic acid electrolyte to ensure calibration from cell to cell which is not only time consuming but prone to error, acid burns and exposure to inhalation of carcinogenic sulfuric acid mists.
Another significant weakness is that positive plate corrosion doubles for every 18 degrees rise in battery temperatures above 77 fahrenheit, an often troublesome and unavoidable factor for numerous climates and operating conditions. Additional concerns such as keeping the terminals and connections free of corrosion, venting, spill containment, exposure to lead and replacement more often than you'd like lend you to think that there has got to be something better out there. There was, and it wasn't a lithium ion battery either!
Aquion Energy offered something different than all others and was the first technology I offered that made my installations less toxic and more environmentally friendly. Over the course of 18 months I installed a total of 8 systems with Aquion Energy batteries for private parties and in April of 2017 installed the 9th set for my own residence. Aquion Energy had been in commercial production since 2014 and were easily promoted as one of the safest batteries around. The environmental aspects of being the only battery with Cradle to Cradle certification was quite impressive as well and put them in a class of their own. Unfortunately, not all technologies get the funding they need to survive in the world of innovation and Aquion Energy suffered a serious blow during the first week of March 2017 when the venture capitalists pulled the plug and the company filed for Chapter 11 bankruptcy. Bringing a new electrochemistry and battery platform to commercial scale is an extremely complex and time consuming process. Despite a very passionate network of early adopters, distributors, innovators and dealers the very capital intensive effort was not enough to prevent the company from going under and temporarily leaving a large void in the energy storage space. In June of 2017 they were acquired by Juline-Titans, a shell company for Titans Energy of China. Their intention is to now manufacture in China and re-release the product sometime in the future but it is unclear if Cradle to Cradle certification will be retained.
Luckily my disappointment of Aquion Energy's departure was short lived and the search for the ultimate battery led me to Blue Planet Energy Systems and their Blue Ion2 product line. This change of events was a blessing in disguise as Blue Ion has proven to be one of the best performing, commercially available, feature boasting energy storage solutions that I've ever worked with. Please see their page to understand why Blue Ion is the best value and performer for your future energy storage asset.