| Website | fireflyenergy.com |
| Category | Cleantech |
| Phone | +1.309.222.2600 |
| Employees | |
| Founded | 5/03 |
| Total | $29M |
| Series A, 10/04 KB Partners United Defense, L.P. | $4M |
| Series B, 11/06 KB Partners KB Partners Heartland Capital Network | $10M |
| Series C, 6/08 Quercus Trust Khosla Ventures Infield Capital | $15M |
Firefly Energy is a developer of lead-acid battery technologies. The company’s first applied technology is a microcell foam-based battery technology. Firefly Energy was launched as a spin-out from Caterpillar on May 1, 2003.