Why Jehu recommends using LiFePO4 batteries
LiFePO4 batteries have been around for a long time, but only recently have become cost-effective and accessible for DIY applications. One major advantage that LiFePO4 has over lithium-ion chemistries is its thermal and chemical stability, which means improved battery safety. Here's a list of why Jehu Garcia recommends using LiFePO4 batteries:
- LiFePO4 is intrinsically safer through its omission of cobalt (cobalt encourages thermal runaway). LiFePO4 chemical P-O bonds are very strong, such that if it is abused (short circuited, overheated, etc), the oxygen atoms are released more slowly, promoting faster ion migration while discouraging thermal runaway.
- LiFePO4 cells are more structurally stable than LiCoO2 cells because they do not undergo significant non-linear expansion.
- LiFePO4 cells are harder to ignite if they are mishandled. Instead of resulting in exothermic reactions like other lithium cells, they are highly resilient during oxygen loss.
- LiFePO4 can offer a longer cycle life than other lithium batteries.
- LiFePO4 batteries can put out a constant output voltage (close to 3.2v) until the cell is exhausted, allowing the cell to deliver virtually full power until it it fully discharged. This means that it can simplify, or in some cases eliminate, the need for voltage regulation circuitry.
- Because of the nominal 3.2 V output, four (4) cells can be placed in series for a nominal voltage of 12.8 V. This comes close to the nominal voltage of lead-acid batteries. This makes LiFePO4 a good replacement for lead-acid batteries in applications such as automotive and solar applications (provided the charging systems are adapted not to damage the LiFePO4 cells through excessive charging voltages beyond 3.6 volts DC per cell while under charge), temperature-based voltage compensation, equalization attempts or continuous trickle charging.
- LiFePO4 has higher current or peak-power ratings than LiCoO2.
- LiFePO4 cells have a longer calendar-life (slower rate of capacity loss) compared to many other lithium-ion battery chemistries such as cobalt (LiCoO2) or manganese spinel (LiMn2O4).
- Unlike LiCoO2 cells, LiFePO4 doesn’t contain nickel or cobalt, both of which are scarce, expensive, and can require dangerous mining.
LiFePO4 cells offer greater stability and safety than other li-ion cells, making them a great choice for Jehu's DIY projects, and also for yours.