Buyers Guides

Lithium batteries – UN38.3 battery testing and certification

UN38.3 certification has been specifically set up to cover the safe storage and shipping of lithium batteries.


Lithium ion electric bike batteries are safe as long as they have been built to the correct standard.

Before you consider buying an electric bike, first check that the battery has been tested and certified to UN38.3. This certification is required by law world-wide for battery transportation and certifies that the battery is safe to store and transport.

Checking for correct certification is very easily achieved by visiting a bike manufacturer’s or distributor’s website. If you have any doubt please ask to see a copy of the certification for the specific battery used on the electric bike you are considering.  The certificate is simple to check, images of the battery certified with weights and serial numbers will be clearly shown if the certificate is correct and valid.

You are also advised to inform your household or commercial insurer that you have Class 9 Dangerous goods in the form of lithium batteries with a capacity of more than 100Wh stored in your premises.

Real world experience

We carry batteries around constantly in our everyday lives: we walk around with them in our trouser pockets, put them on our bed-side tables and even into children’s cots. Batteries are in dolls, mobile phones, alarm clocks, laptop computers, remote controls, cards, bicycles, lawnmowers, cars and much more, they have spread their influence almost everywhere in our daily existence.

Hannes Newport

So we implicitly trust that these batteries will only discharge their stored electrical energy how we wish – in the form of music from an MP3 player, in the form of transmitted speech on our mobile phones, and more recently in the form of a tailwind for our bikes. But unfortunately it is occurring ever more frequently that batteries release their stored electrical energy, and their chemical energy which is even greater than the electrical, in an uncontrolled manner and without warning.

Now, ExtraEnergy estimates, the market is much larger, with around 2 million lithium batteries sold in the light electric vehicle sector. And there are currently developments in China, which suggest that by 2015, annual sales in China alone of lithium batteries for the LEV sector will reach over 10 million. Lithium batteries over 100Wh capacity are, because of the many incidents, now classified by the United Nations as Hazardous Goods Class 9.

Extract from article by Extra Energy

The reality

Batteries designed with state of the art technology withstand all three of the most serious forms of customer misuse.  UN38.3 certifies batteries are safe in these areas.


1.  Overcharging

The moment when the battery overflows with energy.

Occurs when the battery is fully charged but the charger carries on pumping more energy into the battery pack.

Unsafe – Eruptive conflagration shortly after exceeding the final charge voltage

Safe – Cells bulge due to overcharging and break their housing as a result, but have not ignited. Gases or fluids have not leaked.

2.  Short circuit

The full energy of the battery discharges so quickly that the battery overheats or can explode. Fire can also be caused by overheating cables, which ignite insulation or other nearby plastics.

Unsafe – Eruptive conflagration shortly after a short circuit

Safe – The BMS (Battery Management System) switches off quickly. In the second phase the electronics are bypassed. So the battery heats internally to over 100° C, but then cools again. Some fluid electrolyte has appeared, but no gases or other fluids.

3.  Physical damage

Mechanical damage to the battery pack, in a crash or by dropping it, can easily cause an internal short circuit, which can provoke an even more dramatic reaction than an external short circuit.

Unsafe – Eruptive conflagration shortly after a crash.

Safe – Mechanical destruction of the battery housing, squashing the cells but no heating, no leakage of gases or fluids.

Transportation safety

Through legally required battery testing to UN38.3

Battery safety is usually taken as a given. But because practical experience has proven otherwise, the United Nations have dealt with the issue appropriately, and set out mandatory rules for their area of responsibility, which is transportation. These rules are the legally required minimum standards required of batteries for safety in transport.

Hannes Newport

The test procedure for verification of transportation safety according to UN 38.3 describes the tests, which must be successfully passed by battery packs before the battery pack manufacturer can supply them. However compliance with this requirement is in reality not yet monitored, which means that many manufacturers do not carry out these tests or they supply test reports, which originate from similar battery packs. So it is to be recommended that only test reports that contain a detailed description of the battery type be accepted. To unambiguously identify the battery pack, the test report should as a minimum include the following details: type designation, dimensions, weight, photos from each side and illustration of the specification plate.

It is also wise to check carefully what is in the test report; batteries have been supplied with a negative test report, without anyone spotting it. Naturally only batteries, which have fulfilled all of the criteria, can be sold. In many cases too, pre-production samples were used, which may well have changed before full production.

Excerpt from article by Extra Energy Germany

Lithium battery UN38.3 testing

Courier companies have started to refuse to carry batteries that do not conform to UN38.3 and have passed the tests and been certified in an approved laboratory.

General tips for dealers and EAPC users

  • Never charge non UN38.3 approved batteries overnight or unattended.
  • Never use chargers which have an unambiguous connector. Always use a charger which is exclusive to one company and matched to the battery.
  • Inform your fire insurers that Hazardous Goods Class 9 in the form of lithium batteries (containing NO metallic lithium) will be charged and stored in your premises, so that in case of a fire your insurance protection is valid.
  • Longer-term storage of batteries should be separate from the bike and charged on the 39V setting if the charger has the facility or for 2/3 hours every 3 months.
  •  Recycling of used batteries should be actively encouraged and thereby help fulfil the legal minimum requirements of the European Recycling Directive.

Specific tips for electric bike dealers

Check that all batteries you sell have UN38.3 test certification.  Check that the certification is for the specific battery you carry. The easiest way to do this is to check weights and photographs in the report made available to you by your supplier exactly match batteries covered.

Never display batteries in a window that could be expose the batteries to direct sunlight. Instead, ask us for empty battery casings for display purposes.

Carry out staff training in the correct procedures for receiving and sending Class 9 hazardous goods.  One member of staff should have taken a course and have been certificated.

Ensure certified hazardous goods packaging is available for shipping batteries.

Inform customers of battery safety practices.

Detailed advice and notes regarding legally handling Lithium Ion battery packs in the UK and Europe

1.    Lithium Ion batteries, rated 100Wh or more, are classified Class 9 Dangerous Goods for the purposes of transportation anywhere in the world.

2.   All Lithium Ion Batteries, manufactured anywhere in the world, must be certified to UN Manual of Tests & Criteria Chapter III subsection UN38.3, whether sold in equipment or not.

3.    The UN38.3 test is a manufacturing requirement and the manufacturer MUST evidence both this and a Quality Manufacturing Program.

4.    No Lithium battery can be offered for transport, whether or not installed in a bicycle, unless the person or organisation offering that battery or bicycle has evidence that tests have been carried out, and has documentation showing evidence of a Quality Management System from the battery manufacturer.

5.    It is a criminal offence to offer for transport Lithium Ion batteries that are not certified to UN38.3 standards. Severe penalties apply to any person that offers Dangerous Goods for transportation that are not in compliance, this could be up to 2 years in prison plus unlimited fines whether or not an incident arises.

6.    Any company offering Lithium Ion batteries for transportation must employ staff trained and certified in receiving and sending Dangerous Goods. Certification must be renewed every 24 months.

Details of training courses are available from BEBA.

7.    Any company supplying a Lithium Ion battery, and cannot show evidence of the supporting testing to UN38.3, would almost certainly be uninsured against commercial losses in a civil recovery by the carrier or an injured party.

8.    The authorities have started to crack down in this area. This is due to the fact that, it is the failure of manufacturers to comply with the tests, and criteria, that are believed to be the reason for a number of recent fires in transport.

9.    As an importer of Dangerous Goods into Europe, incorrect packing and marking would be the liability of the importer under ADR, which makes the importer the “consignor”.

10.  All electric bicycle suppliers should notify their insurers that they are selling lithium battery powered vehicles.

11.  Companies that receive, unload, load or offer for transport, more than 333kgs of batteries* (in most cases less than 100 e-bike batteries), are required to appoint a DGSA (Dangerous Goods Safety Advisor).  This applies whether the batteries are installed in bikes or not. 

* The weight of the batteries only within any single consignment.

12.  A battery can be offered for transportation, without restriction, by road, if the battery is installed and securely fastened in the battery holder of an e-bike. In such a manner to prevent damage, short circuit or accidental activation. It is not permitted to include spare batteries in the same carton.  This does not apply if sending more than 333kg of batteries in the same consignment (see 10).

Further advice regarding the transportation and storage of lithium electric bike batteries is available from

David Miall,  FreeGo Wisper Group