I am looking to buy a battery load tester to further equip my toolchest. Can someone please tell me what the maximum Amperage rating I should obtain? I can many of those cheapos but only can pull an amp load of maximum 100Amps. While the more expensive SnapOns can pull up to 500Amps. As far as amperage load is concerned, hhat is the necessary-sized battery load tester one should keep on hand to repair benzs, e.g. W124

Dont know how much is in your allowance, but midtronics makes a pretty easy and somewhat reliable tester....they also have battery/charging/starting tester in one:

http://www.midtronics.com/home/home.aspx