⚠️ SAFETY WARNING — Battery Layout Tool
This tool generates reference diagrams only. It does NOT replace professional electrical engineering, code compliance, or hands-on training.
Lithium cells contain high energy. Incorrect assembly can cause fire, explosion, severe burns, or death.
You assume full responsibility for any build
Diagrams may contain errors — verify independently
Author accepts no liability for damages
Follow local regulations and standards
🔋 Cell Selection
- Use cells from the same batch with matched capacity and internal resistance (IR).
- Never mix old and new cells, or different chemistries.
- Verify cell authenticity — counterfeit cells are a major hazard.
- Inspect cells for damage, swelling, or leakage before use.
⚡ Voltage & BMS
- Always use a BMS rated for your pack's voltage, current, and chemistry.
- Set OVP ≤ 4.25V/cell (Li-ion) or ≤ 3.75V/cell (LFP).
- Set UVP ≥ 2.5V/cell — deep discharge causes permanent damage.
- Enable temperature cutoff — never charge below 0 °C (lithium plating).
- Enable balance function; check balance current vs cell count.
🔧 Assembly
- Work with cells at ≤ 50% SOC during assembly to reduce arc energy.
- Never short-circuit terminals — even briefly; arcs cause fires.
- Insulate all exposed contacts with fishpaper, Kapton tape, or heat-shrink.
- Use proper nickel strip or copper busbar rated for the pack current.
- LFP prismatic cells require compression plates at 10–12 PSI.
🔌 Charging
- Use a charger matched to your chemistry (Li-ion CC/CV 4.2V, LFP 3.65V/cell).
- Charge at 0.3–0.5C for longevity; never exceed 1C without thermal monitoring.
- Never leave a charging pack unattended — especially first charge.
- First charge: charge to 50%, check all cell voltages & temps, then complete.
- Charge in a fire-safe location away from flammable materials.
🌡️ Thermal
- Mount BMS temp sensor at the hottest cell; cutoff at 45–50 °C charge, 60 °C discharge.
- Ensure adequate ventilation in the enclosure.
- Cells swell at end-of-life — design enclosures with expansion space.
🔒 Protection & Storage
- Always fuse B+ at 1.5–2× max pack current, mounted as close to B+ as possible.
- Store packs at 30–50% SOC in a cool, dry, fireproof container.
- Damaged or swollen packs: discharge fully in sand bucket before disposal.
- Follow local regulations for disposal — lithium cells are hazardous waste.
📋 Standards Reference
- IEC 62133 — Safety for portable sealed secondary lithium cells
- UL 2054 — Household and Commercial Batteries
- UN 38.3 — Transport testing for lithium batteries
- NFPA 855 — Standard for Installation of Stationary Energy Storage Systems
- Always consult local electrical codes and authority having jurisdiction (AHJ).