Battery Advice needed please !


Just Joined
Feb 4, 2014
Hi all, I wonder if anyone could offer advice regarding batteries.
I recently purchased a 10 year old bike but it did not come with a battery, the original battery was a 24v Ni-MH type.
Where can I source a replacement battery for my bike ? I can't afford to buy a Lithium, so what would be the most economical way of finding a battery for it ? ( the original manufacturer that made the batteries no longer exists )

One last thing - will the battery need to be Ni-MH type, or is it possible to use say, electric wheel chair batteries?

thanks in advance for any help guys!