This may not be in the “inexpensive” category, but it is good to find one that works well.
We use a lot of rechargable batteries in our house, and in a few places we use standard alkaline or lithium batteries. When you have 50 batteries in a desk drawer, sometimes the full ones and the empty ones (waiting for the recycle bin) get mixed up, especially when the kids have been in the drawer. I’ve had a number of battery testers, but they never seemed to work well, especially the inexpensive testers.
The testers I like apply a load to the battery instead of simply measuring the voltage without a load. I bought the ZTS Mini-MBT9R for $30 from Thomas Distributing who included a free case.
What the product description doesn’t quite say clearly is that there is an included test lead wire (similar to most multimeters) that is used when testing non-9V batteries. For example, if you have a AA battery you want to test, you touch the battery’s positive terminal to the tester and then touch the test lead to the battery’s negative terminal. It’s not extremely ergonomic, but it does work. The test lead can be tucked into a slot around the case’s seam to store it.
Unlike the previous ones, I believe I’ll be using this tester for quite some time to come.