Hydrogen Battery Gas Calculator
Use the hydrogen gas calculator below to better understand how much gas your system generates as well as determine the Lower Explosive Limit (LEL) for your battery room or enclosure.
Total Hydrogen (H2) and Oxygen (O2)
Lower Explosive Limit (LEL) of Hydrogen
LEL with and without FLUX Vents
Total % of Hydrogen in Enclosure or Battery Room
Time to reach critical LEL Concentration
Flooded Lead Acid Battery (FLA) vs. Flooded Lead Acid Battery + FLUX Vent — H₂ / O₂ Gas Output
Advanced options OFF
NOTE: These are engineering estimates for ventilation and hazard assessment based on idealized stoichiometry and user‑provided overcharge assumptions. Actual gas evolution varies with charge regime, SoC, temperature, electrolyte, and hardware. For compliance or hazardous‑location design, consult applicable standards and perform direct measurements.
Copyright © 2025 Flow Systems Recombination Technologies. All rights reserved. This calculator and its associated code, design, and documentation are the intellectual property of Flow Systems Recombination Technologies ("FLUX"). Unauthorized copying, modification, distribution, or use of this software, in whole or in part, is strictly prohibited without prior written permission from the copyright holder. This includes calculation, comparison and or LEL functionality in conjunction with the gas concentration engine.
This tool is provided by Flow Systems LLC strictly for informational estimation of potential hydrogen and oxygen gas generation and approximate hydrogen concentration relative to the Lower Explosive Limit (LEL). It is not a substitute for professional engineering analysis, code compliance calculations, or a real-time gas monitoring system. All results are estimates based on simplified assumptions (including, but not limited to, ideal gas behavior, uniform mixing, steady conditions, user-entered inputs, and nominal equipment performance) and may not reflect actual site conditions.
Hydrogen is a flammable gas that can accumulate and ignite explosively. Users are solely responsible for verifying all results, providing adequate ventilation, implementing compliant detection and control systems, and following all applicable laws, codes, standards, and manufacturer instructions. Always consult a qualified professional engineer and the Authority Having Jurisdiction (AHJ) before making design or safety decisions.
No Warranties. The tool and any outputs are provided “AS IS” and “AS AVAILABLE”, without warranties of any kind—express, implied, or statutory—including, without limitation, warranties of accuracy, completeness, merchantability, fitness for a particular purpose, or non-infringement.
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No Life-Safety Use. This tool is not intended for life-safety or mission-critical applications and does not replace approved gas detection or control systems.
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