LiPo Battery Safety for Spray Drones

Charging rules

• Let packs cool to near ambient before charging — hot-charging accelerates degradation and risk.
• Charge on a non-combustible surface, away from the mix station, fuel, and the truck cab.
• Never unattended, never overnight. Someone stays with the generator.
• Use the manufacturer's charger and rates; fast-charging every cycle shortens pack life fast.
• Inspect before every charge: swelling, dents, torn wrap, hot connectors, corrosion.

Storage voltage matters

Lithium packs degrade fastest sitting at 100% or near-empty. For anything beyond a day or two, bring cells to storage charge (~3.8 V/cell, roughly 50–60%) — most ag chargers have a storage mode. Store cool and dry; heat is the other great pack-killer.

Retire packs on evidence, not sentiment

Pull a pack from service if it's puffed/swollen, won't hold balance across cells, gets unusually hot, or has lost meaningful capacity (many operators retire at ~80% of rated). Discharge fully and dispose at a battery recycler — never in the shop trash or a burn pile.

If one goes into thermal runaway

Expect white smoke, hissing, then flame; it may reignite. People first — the smoke is toxic. If safe, move surrounding fuel/chemicals away rather than moving the pack. Water in volume is the practical cooling agent (Class ABC for surrounding fire); a small sand bucket helps contain it. Let it burn out in a safe spot and ventilate.

Hauling batteries legally

Large lithium packs are DOT-regulated hazmat when shipped. For your own trucking: protect terminals from shorting, keep packs in a rigid case away from the cab's occupants, secure them so nothing shifts, and carry a fire extinguisher. Consult DOT rules before shipping packs by carrier.

Follows manufacturer and general lithium-safety guidance; always defer to your battery maker's manual. Related: maintenance & pre-flight.