Nater Potater
Well-Known Member
- Oct 19, 2020
- 2,651
- Boat Info
- 1992 300DA Sundancer
- Engines
- Twin Merc Alpha I Gen II I/O's with 5.7 V8's
I won't argue that it's best to pull a higher load than 100 amps, but, even so, that one will weed out a bad battery fairly quickly. I suggested it as a usable tester that wasn't too expensive. However, if so inclined, one could go with their carbon pile load tester. Good for 500 amps. Protocol says to pull 1/2 of the rated CCA for 15 seconds without dropping below 9.6 volts. Probably what I'll do in the near future, as my batch-o-batteries continues to grow. Two in the RV, two in the truck, three in the boat...The first link posted is only a 100 amp unit. A proper "starting" battery test involves bringing the battery to full charge, letting it sit for at least an hour or two and then load testing with a tester that will pull 200 amps for 10 seconds. The battery should not drop below 10 volts and bounce back fairly quickly depending on cranking amp rating.
As to the second link. You really need to spend a lot more than that to get a good electronic digital battery tester.
Note: lead acid, agm, gell, and others all have different charge and testing equipment, specs. and requirements.