DOT’s ruling on lithium ion batteries and airlines: Size matters

Whenever I have a question about the nitty gritty of lithium ion batteries, the folks at Micro Power Electronics are among the first I contact. They came up with a great synopsis of the new regulations on lithium ion batteries and airport carry-on luggage. So, without further ado, here’s Micro Power’s summary article.

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The U.S. Department of Transportation’s (DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA) Lithium battery final rule was published on August 9th, 2007 in the Federal Register. This long awaited rule will harmonize the U.S. lithium battery hazardous materials regulations (HMR) with those that have been in effect internationally since 2003. .

 The publication of the final rule incorporates many of the dictates from the Agency’s previous proposed rule as well as changes from the 2004 interim final rule on lithium metal (primary) batteries. Substantial regulatory and formatting changes to the lithium metal (and lithium ion) battery provisions in U.S. HMR have been unveiled. The effective date of the rule is January 1, 2008; however, some of the special provisions will go into effect later. In this article, Micro Power Electronics will explain the changes and answer commonly asked questions regarding the shipment of Li primary and Li-ion batteries.

All Li primary and Li-ion battery packs, regardless of their size, will need to be tested according to the UN manual of Tests and Criteria prior to their production shipments.

As summarized in the chart below, three categories of batteries are defined in the U.S. DOT’s rule based on their “size.”

Battery and cell category definition

*Equivalent Lithium content

 “Small” battery packs that have passed the UN testing requirements, including batteries packed with or installed in equipment, can be transported “non-restricted.” (That is, the batteries do not have to be shipped as fully-regulated Class 9 hazardous materials.) The actual requirement for testing small battery packs does not go into effect and become mandatory until October 1st, 2009. However, most battery pack manufacturers (including Micro Power Electronics) are already prudently testing these battery packs.

“Medium” size battery packs that have passed the UN testing requirements, including batteries packed with or installed in equipment, can be transported non-restricted by motor vehicle or rail only. If these batteries are to be transported by passenger or cargo aircraft they must be shipped as fully-regulated Class 9 hazardous materials .

“Large” size battery packs that have passed the UN testing requirements, including batteries packed with or installed in equipment, must be shipped as fully-regulated Class 9 hazardous materials.

One of the more significant issues addressed in the U.S. DOT’s rule is confirmation that single-cell lithium battery packs do not require UN testing provided that the cell was previously tested and passed the UN testing as outlined in the Manual for Tests and Criteria.

The U.S. DOT certainly has not finished their work on lithium batteries. We expect the Agency to publish a new proposed lithium battery rule in late 2008 to harmonize its regulations with the changes recently adopted at the international level. For example, starting January 1, 2009 under the international regulations, lithium metal batteries and lithium ion batteries will be assigned separate identification numbers (also known as UN numbers). UN3480 will be assigned to lithium ion batteries (including polymers), while the existing number UN3090 will only cover lithium metal (primary) battery packs. In addition, UN3481 will be assigned to lithium ion batteries contained in or packed with equipment. While the counterpart number for lithium metal (primary) batteries is UN3091.

The determination of the size of a lithium ion battery pack for shipping classification has up to now been done by an unusual calculated measurement of “equivalent lithium” using a formula to come up with ELC (Equivalent Lithium Content). Starting January 1, 2009 for international shipments by air or by sea, the determination is changing to a method of watt hours. Watt hours are defined as the rated capacity multiplied by the nominal voltage. The new exception limits are set at 20 watt hours for cells instead of 1.5 g ELC, and 100 watt hours for battery packs instead of 8 g ELC. The watt hour rating must be placed on the label of excepted battery packs (no more than 100 watt-hours) so it can be seen by users of the product.

Within a couple days of this change, it is expected that the DOT will issue a proposed harmonization ruling which will allow all shippers in the US to use this method as well as long as they are shipping by Air or by Sea only. One important note that should not be overlooked is that after Jan 1st, 2009 shipping lithium batteries by Ground or by Rail in the US will still be required to use the ELC method of determining the size of the battery pack.

Another of the changes on January 1st, 2008 effects most of us that fly with consumer electronic and medical devices is that it will now be specifically prohibited to transport spare battery packs in “checked” baggage. All spare batteries should be transported in carry-on baggage and must conform to the following rules. Each spare battery must be individually protected so as to protect against short circuits. This includes the very popular 9V battery type, as these are very easily shorted while being transported if not protected properly. Each battery installed in a device or carried on as a spare must not exceed 2 grams of lithium if it’s a primary (lithium metal) battery, or have an ELC of more than 8 grams if it’s a Li-ion battery pack. Although up to two battery packs with an ELC of more than 8 grams (but less than 25 grams) may be carried-on as spares.

The USDOT has created a new website (http://safetravel.dot.gov/) as an aid to travelers to answer their questions about how to handle all types of battery packs when traveling by air. We should expect to see and hear more about traveling with batteries in the coming New Year. 

All these regulation changes can be a bit overwhelming to understand and apply to your specific product or shipping patterns, so if you have any questions please contact MicroPower Electronics or visit the PRBA (Portable Rechargeable Battery Association) web site for further information.