Battery-sparked house fires are rising-most start while packs sit on a kitchen counter or hallway outlet. This hands-on guide lets renters, homeowners, and small shops turn any corner of the garage into a UL-inspired "battery fire station" for less cash than a replacement charger. Electrical designer Hannah Ngo breaks the project into three fast sections: BUILD IT - Shop list for two price tiers-$120 bare-bones plywood & intumescent-paint locker, or $190 cement-board + steel-angle enclosure. - Step-by-step cuts, screws, and silicone sealant routines; no welding, no 240 V wiring. - Venting & active cooling tricks that keep pack temps under 40 °C during fast charge. SENSE IT - How to choose a budget photo-electric / CO combo sensor that alarms at the earliest whiff of thermal runaway. - Mount-height rules, battery-back-up settings, and free phone-alert apps. - One-page wiring diagram for an optional smart-relay that kills power when smoke is detected. LIVE WITH IT - Daily checkpoints to spot swelling cells and counterfeit chargers before they ignite. - Charge-cycle myths that murder battery life-and how to double your pack's lifespan. - Disposal, recycling, and insurance paperwork tips that keep you legal and covered. Real-world case studies from NYC e-bike messengers, a Colorado carpentry shop, and a London flat share prove you don't need luxury gear to stay safe-just the right materials and a weekend of effort.