If you use a Nikon camera that uses this battery there is a safety recall for a series of this battery.
I don't know the full list of models that use them but I know the D50 and D70 Digital SLRs do.
Checkout the trading standards website under product recalls.
Here
When you register your equipment with Nikon they will automatically tell you when the serial number of your battery is one of the listed ones.
They will then send you pre-paid return packaging for you to return the battery then on receipt they send out a replacement.
My replacement arrived today and is the higher spec EN-EL3a model.
I'm glad I bought a spare battery when I got the camera though if I'd done my research I wouldn't have got the spare from Jessops but from Valuemedia.co.uk as they are about a third of the price I paid Jessops for their own branded battery.
