Compression Ignition Addict
Join Date: Jun 2011
Location: Colorado Springs
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Using your DVOM, make sure the test leads are plugged into the right connections (usually volts/ ohms) and put the red to the + terminal of the battery, the black to the negative.
Depending on temperature a good battery will generally be in the range to 12.8 - 13.2 volts. However, just because the voltage looks OK does not mean the battery is good. It could be sulfated, dead cell, etc... and still have OK looking voltage.
The only good way to test is to see how the voltage drops under high current draw conditions. If you do not have a carbon pile tester, the auto parts store will be able to do it for you. They draw a bunch of current through the tester and watch how the voltage drops off. Usually the tester is automated so that the user can't mess it up. Best to have your batteries fully charged before you have them tested.
2005 F-250 6.0L, crew cab, long bed 4x4
completed in 2011: STC update, new IPR, BPD EGR cooler, oil cooler rebuild, 6.4 banjo bolts, blue spring update, SCT X3, Insight CTS, 58V FICM, CCV Mod, DIY coolant filter (now gone)
, refinished turbo
2012: ARP headstuds, OEM gaskets, standpipes and dummy plugs
2015: XDP coolant filter