Picked up a set of parts to test a set of portable "power generators" we acquired. <br/><br/>Can put a precision load on a battery. <br/><br/>20 amps max. Requires a separate 12 volt plus or minus .5 volt power supply.<br/><br/>250W DC 12V Discharge Battery Capacity Tester Module With DC Electronic Load...<br/><br/>From China through a us distributor<br/><br/>I added an in-line from battery source powerwerks gauge...