You've probably heard of lithium-ion batteries catching fire in small devices like phones...well the discovery of lithium iron phosphate (LFP or, technically, LiFePO4) has brought much-needed safety and stability to the lithium battery market. With this safer chemistry and high-quality manufacturing from companies like SimpliPhi and Relion, lithium iron phosphate batteries are becoming widely adopted for off-grid energy storage. Yes, they're more expensive, but consider their benefits:
- High energy density - a minimum 2.5x that of lead acid batteries
- Highly efficient so you get out most of what you put in - very little energy is lost as heat
- Outstanding life expectancy - up to 10,000 cycles
- No maintenance or memory problems - there's no need to exercise them (periodic discharging and recharging), so they're great for both full-time and intermittent/infrequent applications
- No additional cost for the sealed format - LFP cells are sealed and can be installed in a living space, and in any orientation
Aside from the initial cost, the major disadvantages of LiFePO4 batteries are the same as other batteries - low performance at freezing temperatures, and damage if operated above maximum or below minimum parameters. SimpliPhi's Smart-Tech series has implemented a real-time equalization circuit - the weaker cells are dynamically cared for so they're not overstressed. This in combination with the solid-state protection circuit makes for highly reliable and effective off-grid energy storage.
Budget approximately $1.20/Wh for small systems, or as little as $1/Wh for large systems.
Lithium-Ion Batteries from Real Goods
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