There are 4 different types of Mobile Phones batteries for sale on eBay.

1. Generic - Generic batteries are not made by the original phone manufactures, but  by third party manufactures. The batteries are also called NON-OEM (Non Original Equipment Manufacturer). These batteries offer a cheap alternative to genuine batteries, but may have a lower capacity.
2. Original or Genuine New Blistered - These batteries are made by the makers of the phones and come in retail packs, often with warranties included.
3. Original or Genuine New Bulk - These batteries are made by the makers of the phones and have no packaging except a small protective bag.
4. Grade A’s or Nearly New - These batteries often come from network returned phones. These phones have been returned to the networks within the two week cooling off periods. The networks remove the batteries and install new batteries. It’s worth confirming with the seller that these are no older than 14 days.

What to watch out for when buying a new battery.

• The picture may show a genuine battery, but the detail in the listing may say generic or non-oem – this is not a genuine battery.
• Seller selling genuine batteries for significantly less than others might be selling Grade A batteries as new.
• Fakes – sadly there are many fakes, check a sellers feedback.
• Distance Selling / Drop Selling - The location of the battery might be show as the UK and have pictures of Union Jacks etc, but the battery comes from Hong Kong / China. Have a look at the Stars next to a sellers feedback, if dispatch time is less 4.7, check the sellers feedback in detail. You will have a 10 day wait on your hands if it is.
  

When you get your battery.

• If you have purchased a new battery, there should be no marks on the connectors.
• Most Nokia batteries have a serial number than can be checked on the Nokia website.
• Motorola batteries usually have a hallmark.