Jebiruph
Well-Known Member
- Thread starter
- #1
Checking the voltage of the batteries is a good start, but a battery with good voltage can still fail when under a load. To really test the batteries, you need a load tester. Some auto parts stores will load test your battery for you, but having dual batteries complicates the testing. To do my own testing, I found a cheap load tester online for less than $25. Harbor Freight has them too (plus free voltmeter with coupon). These cheap load testers are basically a heating element (uses a lot of power) shielded in a metal box with a voltmeter built in. It's not a sophisticated load test, but it's better than nothing.
The testing is basically the same as testing voltage. The difference is after everything is hooked up, you press a button to turn on the tester and place a load on the battery. If the voltage of the batter drops too low under load, it's a bad battery. The tester should only be turned on briefly, just long enough to read the voltage. This first picture shows the tester heating up when left on too long. It will melt plastic, so be careful. Mine turned the magazine it's sitting on brown from the heat.
To test, I disconnected the main battery positive terminal to isolate the batteries and used a digitalt meter to read voltage (instead of the meter on the load tester). Here's testing the Main battery with the tester connected to the positive post and the negative terminal. Normal voltage was 12.68v, loaded test voltage was 11.33v.
Here's testing the Aux battery with the tester connected to the disconnected positive terminal and the negative terminal. Normal voltage was 12.41v, loaded test voltage was 10.59v.
The meter on the tester indicates the good/bad voltage ranges. Both the 650 amp Main and 200 amp Aux batteries passed the load test.
(updated 04/13/2019)
Additional 3.6L ESS system information is available here.
3.6L ESS Dual Battery Consolidated Information
https://www.jlwranglerforums.com/forum/threads/3-6l-ess-dual-battery-consolidated-information.2
The testing is basically the same as testing voltage. The difference is after everything is hooked up, you press a button to turn on the tester and place a load on the battery. If the voltage of the batter drops too low under load, it's a bad battery. The tester should only be turned on briefly, just long enough to read the voltage. This first picture shows the tester heating up when left on too long. It will melt plastic, so be careful. Mine turned the magazine it's sitting on brown from the heat.
To test, I disconnected the main battery positive terminal to isolate the batteries and used a digitalt meter to read voltage (instead of the meter on the load tester). Here's testing the Main battery with the tester connected to the positive post and the negative terminal. Normal voltage was 12.68v, loaded test voltage was 11.33v.
Here's testing the Aux battery with the tester connected to the disconnected positive terminal and the negative terminal. Normal voltage was 12.41v, loaded test voltage was 10.59v.
The meter on the tester indicates the good/bad voltage ranges. Both the 650 amp Main and 200 amp Aux batteries passed the load test.
(updated 04/13/2019)
Additional 3.6L ESS system information is available here.
3.6L ESS Dual Battery Consolidated Information
https://www.jlwranglerforums.com/forum/threads/3-6l-ess-dual-battery-consolidated-information.2
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