UN38.3 battery certification

UN38.3 is the standard that batteries should get certified to for for transport by air, water, rail or road. Most carriers require this certification for transport of lithium batteries.

The tests are pretty common sense and reasonable. Vibration, altitude, temperature, short circuit, impact, overcharge etc. all things a battery could experience during transport with poor packaging. DIY people don’t typically do these tests, but should think about the criteria as it helps build a safe pack.

The short circuit test is interesting. The battery is heated to 55°C and the terminals are shorted.

With a battery where the discharge passes through a BMS, the BMS will trip and make the battery safe (provided the FETs don’t fail shut, which is unlikely)

With a battery with fuse, the fuse should pop rendering the battery safe.

But what if the battery does not have a fuse, charges via the BMS, and directly discharges from the cells?

Pass criteria is that the battery case temp does not exceed 170°C, no rupture, no flames, no disassembly.

My assumption is that the battery would heat, and eventually combust, that’s if the solder doesn’t melt and break the circuit first?