How AVD Fire Suppression Works: The Science Behind Lithium Battery Fire Control
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The Problem with Conventional Fire Suppression
When a lithium-ion battery enters thermal runaway, it creates a fire unlike anything conventional extinguishing agents were designed to handle. The battery generates its own oxygen internally through exothermic chemical decomposition, meaning CO₂ — which works by displacing oxygen — is largely ineffective. Dry powder suppresses surface flames but cannot penetrate the battery casing. Water can cause violent steam reactions and spread burning electrolyte.
The result is a fire that appears extinguished but continues burning internally, often reigniting hours or even days later.
AVD (Aqueous Vermiculite Dispersion) was developed specifically to solve this problem.
What is AVD?
AVD stands for Aqueous Vermiculite Dispersion. It is a water-based suspension of exfoliated vermiculite — a naturally occurring mineral — combined with a proprietary blend of additives that give it unique fire-suppression properties for lithium battery fires.
AVD was developed in the UK and has undergone extensive independent testing and certification for use on lithium battery fires. It is now the internationally recognized standard for lithium battery fire suppression.
How AVD Works: The Three Mechanisms
1. Rapid Cooling
The water component of AVD absorbs enormous amounts of heat through evaporation, rapidly cooling the battery surface and the surrounding environment. This slows the thermal runaway reaction and reduces the risk of fire spreading to adjacent cells or battery packs.
Unlike plain water, AVD's formulation allows it to be applied in a controlled manner without causing the violent steam explosions that can occur when water contacts a burning lithium battery directly.
2. Protective Coating
The vermiculite particles in AVD are microscopic and highly adhesive. When applied to a battery, they coat the surface of individual cells, forming a physical barrier that:
- Insulates cells from external heat sources
- Prevents oxygen from reaching the battery surface
- Reduces the rate of gas venting from damaged cells
- Physically separates cells to slow thermal propagation
This coating effect is what makes AVD fundamentally different from all other extinguishing agents — it doesn't just suppress the fire, it creates conditions that prevent reignition.
3. Reignition Prevention
The vermiculite coating remains on the battery surface after application, continuing to provide thermal insulation and a physical barrier even after the fire is out. This is the critical advantage of AVD over all other agents: it dramatically reduces the risk of reignition, which is the primary danger of lithium battery fires.
Independent testing has demonstrated that AVD-treated batteries show significantly lower reignition rates compared to batteries treated with water, CO₂, or dry powder.
AVD vs. Other Extinguishing Agents
| Agent | Cools Battery | Penetrates Casing | Prevents Reignition | Safe to Apply |
|---|---|---|---|---|
| Water | Partially | No | No | Risk of steam explosion |
| CO₂ | Slightly | No | No | Yes, but ineffective |
| Dry Powder | No | No | No | Yes, but ineffective |
| AVD | Yes | Coats externally | Yes | Yes |
AVD in Practice: Our Product Range
AVD technology is available in several formats to suit different applications:
AVD 2L Fire Extinguisher
Compact and portable, ideal for e-bikes, scooters, power tools, and home use. Easy to operate and store.
6L AVD Lithium Ion Battery Fire Extinguisher
The standard choice for passenger EVs, EV charging facilities, and commercial applications. Provides sufficient agent volume to suppress a full EV battery fire and prevent reignition.
AVD 50L Wheeled Lithium Ion Battery Fire Extinguisher
Designed for large-scale applications: electric bus fleets, logistics depots, and large EV charging infrastructure. Provides maximum suppression capacity for high-risk environments.
Lithium Battery AVD Fire Blankets
AVD technology is also available in fire blanket form. The blanket is impregnated with AVD agent and works by wrapping around a burning battery to contain the fire, suppress flames, and prevent spread. Ideal for early-stage intervention on smaller batteries.
AVD Fire Suppression Kit
A complete suppression solution combining extinguisher and blanket for comprehensive protection.
Why AVD is the Only Proven Solution
As lithium battery technology has proliferated — in EVs, e-bikes, energy storage, and consumer electronics — the fire safety industry has tested dozens of potential suppression agents. AVD has consistently outperformed all alternatives in independent testing for lithium battery fire suppression and reignition prevention.
It is now specified by fire safety authorities, EV manufacturers, and fleet operators worldwide as the standard for lithium battery fire response.
Get the Right AVD Solution for Your Needs
Whether you're protecting a single e-bike or an entire EV fleet, there's an AVD solution sized for your application. Contact our team for expert guidance on choosing the right product.