AIS 156 and Battery Safety: What to Check When Buying an Electric Two-Wheeler

After a series of electric two-wheeler fire incidents in India drew public and regulatory attention, the testing requirements for EV traction batteries were strengthened, particularly around thermal behaviour and how a pack responds when one cell fails.

For a buyer, the practical takeaway is that certification is now a meaningful filter. A manufacturer that has done the testing has documentation. One that has not, does not.

The detail is technical, but the categories are understandable. Battery safety testing broadly examines whether a pack survives, and fails safely under:

• •Thermal stress. Behaviour at high temperature, and what happens if one cell goes into thermal runaway — whether it spreads to neighbouring cells or is contained.
• •Electrical abuse. Over-charge, over-discharge, short circuit and over-current conditions, and whether protection operates correctly.
• •Mechanical abuse. Vibration, shock, drop and crush — the everyday reality of Indian road surfaces.
• •Environmental exposure. Water, dust and humidity ingress.
• •Protection systems. Whether the BMS actually does what it claims when conditions go out of range.

• •The test report or certificate for this specific battery model, from a recognised testing agency
• •The chemistry, in writing — LFP, NMC or other
• •The BMS protections, listed individually, including thermal cut-off on both charge and discharge
• •The IP rating for water and dust
• •Whether the charger supplied is matched to this pack
• •Warranty exclusions in full

A seller who can produce all six is running a real business. One who offers a laminated certificate with no issuing agency, or who says testing is “not needed for this model”, has told you what you need to know.

A certificate applies to a design as tested. It does not guarantee that every unit off the line matches it, and it says nothing about what happens after the pack leaves the factory.

Three things reintroduce risk regardless of certification:

• •Using a non-matched charger, which is the most common avoidable cause of serious failures
• •Roadside repair or opening of a lithium pack by someone without the right equipment
• •Continuing to use a pack after impact, submersion, swelling or a burning smell

Whatever certification a pack carries, stop using it and call your service provider if you see swelling or a change in the casing shape, smell anything sharp or chemical during charging, see smoke or sparks, find the casing too hot to keep a hand on, or if charging runs far longer than normal.

Do not open a suspect pack and do not hand it to an unequipped repairer. Our daily check routine catches most of these early.