In reply to idiotproof (Buxton MC): Be aware that Cree is basically a semiconductor manufacturer - see
https://en.wikipedia.org/wiki/Cree_Inc. and
http://www.cree.com/ The only lights they make are for fixed interior and exterior illumination - they certainly don't make bike lights. A lot of high-power bike lights and torches use Cree LEDs but the rest of the package - in particular the housing and the battery - will be sourced separately and built up with the Cree LED to make the finished product.
A great many of the cheap Chinese manufacturers use the Cree name in their product descriptions because, with Cree being one of the early entrants into the high powered LED market, the name gives their product a certain cachet. However, it's no guarantee of the quality of any other part of the product. In fact it's no guarantee that they even used the best or latest LEDs from Cree; they could even have bought a reject batch and used the ones that worked (a la Clive Sinclair) or worse still just used the whole batch on the basis that the things are so cheap to make that duds can simply be replaced when the customer complains (good luck with that if you bought direct from the distributor in China or Hong Kong). Just as with "Intel inside", the use of the Cree name gives no indication of whether a third-party accessory such as a charger will be compatible with the product as a whole.
I think tim000's advice is reasonable: buy another one of the product you've already got (if you can't remember which one it is, have a look back through your Amazon order history). Even if you do order the wrong one, you'll at least have a working set of compatible light and charger. And those generic Chinese lights are usually cheap enough to treat as being essentially disposable* - certainly in comparison to a quality branded product.
Or you could bite the bullet and spend more on a decent branded light (see this recent thread
https://www.ukclimbing.com/forums/t.php?t=625721 for some suggestions) which will hopefully have better after-sales support for spares & repairs.
* Although the batteries should not be put in landfill. Lots of shops (eg B&Q, many supermarkets and garden centres) have dedicated battery disposal bins, or your local authority should be able to accept them either at one of their recycling centres or via the kerbside recycling collection.<?i>
