A method and apparatus for simulating a battery tester with a fixed
resistance load, such as a widely used Japanese load tester that rates
the strength of Japanese batteries that are categorized under the
Japanese Industrial Standard (JIS), are provided. This invention
simulates such a device without invoking large current loads, yields
familiar results, utilizes an existing database and provides more
conclusive testing. The method includes estimating a battery load test
voltage as a function of a measured battery dynamic parameter, an open
circuit voltage, the load resistance value of the load tester and the
battery temperature. A bounceback voltage (BBV) of the battery is also
predicted. The BBV, load voltage and battery temperature are utilized to
rate the strength of the battery. Also, to improve the accuracy of test
results for a substantially discharged battery, one embodiment projects
the results of recharging discharged batteries without actually doing so.