The first information to provide would be the make and model of the equipment that you require the battery for e.g. COMPAQ Laptop batteries , or COMPAQ Laptop batteries . There is also usually a label on the COMPAQ battery, and some of this information on the label will help our sales team to identify your battery quickly.This information includes the voltage of the COMPAQ Laptop batteries battery pack (note: this is not the same as the voltage on the power supply), the capacity of the COMPAQ battery pack and the chemical construction of the COMPAQ battery pack e.g. .Li-ion, Ni-MH or Ni-Cd. This information can be used to ensure the information you have provided matches the information we have about your battery. Many battery packs also have part numbers on the label; this can sometimes be used to help identify the COMPAQ Laptop batteries battery. We would suggest that it is best to have all this information written down or close to hand before you call our sales team. This will help us deal with your call in an efficient manner.