Hello and thanks for offering to help. I have been looking for a Lithium flat-pack 3.7v 240mah with 2-leads. I did find a fair amount of them, but they appear to be replacement versions. So, I called a large battery distributor and was asked what was it used for? I explained that I was building a project and there was not a part number for this battery. The employee from the distributor stated “all of his Lithium batteries were replacement type batteries” in which I would need to offer additional info.
FYI I did get on-line @ Sparkfun and did not find any 3.7v 240mah Lithiums.
My main question is where I might locate a beginners guide to Lithium batteries. If you can advise me on an in depth book title (you personally have read) I would be ever so grateful.
Thank you for any help you may offer,
Larry Gold
ndlaau@gmail.com
“all of his Lithium batteries were replacement type batteries”
As long as you're [u]not[/u] looking for a battery that has a specific size or shape, the employee is correct. 240mah is just how much capacity the battery has, you can think of it as how many gallons your "gas tank" can hold. A battery close to that capacity should work but you probably want to go up in size unless you can find one really close to 240mah. A 200mah battery would probably be OK as a replacement but you wouldn't want to go with a 150 since the device might be setup to charge a larger battery and could try to charge a smaller battery too quickly.
The closest size battery on the sparkfun website is their 400mah battery, as long as the physical size and shape on that works for you it should work in your device. The only drawback is that it’s going to take roughly twice as long to recharge than the original battery but a plus is it should last about twice as long. 
Hi YellowDog, I didn’t expect such a great reply so quickly. Your info has cleared a number questions that have bothered me. I finally decided to stop working on the project until I knew which battery I would use. Thanks again, you made my day! I hope that your day will be as great as mine. Larry Gold