Many airlines won’t take them as air cargo.
You can send them by ocean freight or intentionally misrepresent and mislabel them. Probably not a good idea for the latter.
From the UPS webste:
Shipping lithium batteries
by air service
Effective 1 January 2015, lithium metal
batteries shipped without equipment
are prohibited on passenger aircraft.
These shipments are limited to the UPS
International Dangerous Goods (IDG)
network. Please see the countries
approved for “IDG”, as shown on UPS
Approved Countries List: Page on www.ups.
While all lithium batteries are classified
as hazardous materials (also referred
to as dangerous goods), there are
exceptions for common small sizes of
these batteries that simplify the rules
for shipping these items. This document
describes the rules for shipping these
small lithium batteries. Shipments not
fully regulated as Dangerous Goods do not
require a UPS Dangerous Goods contract.
Regulations differ depending upon what
type of battery you are shipping (lithium
ion or lithium metal) and whether you
are shipping batteries packed without
equipment, batteries packed with
equipment or batteries contained in
equipment. Please see Figure 3 (Page 4)
and Figure 4 (Page 5) for additional