Keeping your Lithium bank happy and healthy

Early lithium battery chemistries were an attempt to get much greater power-to-weight ratio than was achievable with lead, NiCad, NiMH, etc. Lightness and power are extremely useful in aviation, space launches, RC racing, etc. A side benefit is that lithium does not suffer from partial states of charge like lead does.

Unfortunately for vanfolk, early lithium had cell voltages that didn't line up well with 12v applications, and a disconcerting habit of entering thermal runaway (ie, violently catching on fire).

LiFePO4, the current lithium standard for vandwellers, is much more stable and have cell voltages that work well with 12v power systems. The downside is lower energy density than the flamethrowing versions.

Consumer-grade LiFePO4 batteries prefer:

• moderate charge and discharge rates - ≤0.5C, and ≤0.2C for increased longevity
• at moderate charging voltages - like 13.8v
• allowed to come off charging voltage after attaining the desired SoC - like pseudo-floating at ≤13.6v
• discharging to ≤80% depth of discharge (≥20% state of charge)
• at human-comfortable temperatures. Notably, Li is immediately and irreversibly damaged by charging when cells are at ~freezing temps.