Can I Test How Much Life Is Left in an AGM Battery?

Question:

Is there a way to measure the effective remaining life in used AGM batteries? I’m off to survey the boat Friday, so thought I should ask. - Philip

Answer:

Engine batteries (i.e. cranking batteries) can easily be tested with a carbon-pile load tester or a capacitance battery tester.  Unfortunately, there is no quick and easy way to test deep-cycle batteries.

Battery life is affected by;

• Number of battery cycles
• Depth of discharge
• Frequency of charges to full capacity

- Jeff