A solar power enthusiast recently discovered a serious issue with a lithium battery system built into a mobile trailer. The individual, who had constructed the system several years ago, found that two batteries had swelled significantly, creating a potential safety hazard. This situation highlights the risks associated with aging lithium batteries and the importance of proper maintenance and storage.
The setup included two adjustable photovoltaic (PV) arrays mounted on a cargo trailer’s roof and side, coupled with a solar inverter-charger and a 10-kWh LiFePO4 battery bank. The batteries, initially salvaged and modified from second-hand sources, had functioned well for a period. However, a recent inspection revealed that one of the battery modules had developed an alarming bulge, resembling a “spicy pillow,” indicative of internal chemical reactions and gas build-up.
Understanding the Issue
The batteries in question were originally used in a server rack and purchased from Battery Hookup, a company known for selling refurbished battery modules. After a few months of successful operation, the owner upgraded to new server modules from Ruixu and stored the older batteries in the trailer. Although there was no physical damage to the batteries, they began to swell due to normal aging processes, possibly exacerbated by temperature fluctuations within the trailer.
As the chemical composition of the batteries deteriorated, gases such as carbon dioxide and carbon monoxide accumulated, causing the steel casing to deform. This phenomenon underscores the significant power and potential danger inherent in lithium batteries, particularly when they are not adequately monitored.
The individual acknowledged their oversight in battery maintenance, admitting that they had not routinely checked on the batteries after their removal from service. They expressed concerns about the fire hazard posed not only to their own property but also to nearby structures, including a garage and several vehicles.
Next Steps for Safety
In response to the immediate danger, the owner moved the batteries to a designated area in their yard, referred to as the “Pole of Inaccessibility,” which is the farthest point from any flammable structures. This is a temporary measure while they seek proper recycling options. While some cities have battery recycling programs, the owner suspects that local recycling facilities may not accept such large and damaged batteries.
The Environmental Protection Agency (EPA) provides guidelines for battery recycling, primarily aimed at household batteries. However, the disposal of large lithium batteries requires specialized handling, often beyond typical consumer programs.
The owner has reached out for advice on how to responsibly dispose of these batteries, emphasizing the need for safe practices. As the availability of used lithium batteries increases, particularly from electric vehicles and e-bikes, this situation raises broader questions about the future handling and retirement of lithium battery technologies.
This incident serves as a cautionary tale for those using lithium batteries in DIY projects. Proper maintenance, regular inspections, and understanding the lifespan and risks associated with these batteries are crucial for ensuring safety. As more individuals venture into renewable energy solutions, awareness of these potential hazards will be essential in preventing similar occurrences.
