This is a not an easy question to answer and buying unguaranteed batteries could mean you are being taken for a ride, or it could be a perfectly good bargain.
Why? Well let's suppose you have found the same type of battery as you are now using , what can go wrong?
Many cameras are using the AA size NiMH bateries as they are a well tried technology.
They come in different capacities, the older ones will give 1 amp for an hour, the latest will give about 2.5 amps for an hour, which means they will last about 2.5 times more for your application, your camera.
Now you say you want a PACK, which are batteries preformed in a block. This is the dodgy bit. You normally can't see the manufactureres name on the individual batteries so you don't know how long they will last before needing recharging.
Here we come to the second point. OK, they last as long as the ones you have got at present between recharges, but how many times can you recharge them?
Well if it is any consolation, makers are very coy about quoting the number of times you can recharge a battery, even the reputable ones.
The reason is simple. In the old days physically small batteries were only expected to give small currents and a reasonaable life could be expected. Say 300 recharges or even 1000.
But today size is a premium and the manufacturers to compete must make the batteries small, be it for a portable laptop, a camera or a power tool.
So instead of a large D-size we get the same power from a small AA size.
These batteries now GET HOT. Heat shortens battery life and this is why you should stick with a known brand name and not chance your luck.
As I said in the beginning, the unknown brand ( generic) may be perfectly good, but then again it may give up the ghost after a few recharges.
I hope this may have helped you to decide.