What is a Reasonable Battery Voltage?

Question:

Our batteries lose their voltage quickly when we are at rest. We should have a 600 AHrs bank, after draining 100 AHrs the voltage drops to less than 12v. Should I be worried about their health?

Answer:

From your description your batteries need to be replaced. At 50% discharge (ie. 300 AHrs) your batteries should have 12.2 Volts.

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House Battery + Starter Battery + 2 Battery Monitor Shunts?

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I Am Adding a Second Battery, Should I Use a Battery Combiner or a Battery Isolator?

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Battery Charging Redundancy with a Battery Isolator

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My Battery Charger Has Three Outputs, Can I Connect Them All to One Battery to Charge Faster?

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How to Charge a Lithium Battery House Bank and an AGM Starter Battery at the Same Time?

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Why You Can't Use a Starter Battery as a Deep Cycle House Battery?

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Can You Explain Battery Capacity and Battery Voltage?

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Using A Battery Switch While the Boat is Running - Good or Bad?

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How to Monitor Lithium Battery State of Charge Without Bluetooth

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I Purchased a 3-Output Battery Isolator but I Only Need 2 Outputs - Can I Leave One Unwired?

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I Purchased a 3-Output Battery Isolator but I Only Need 2 Outputs - Can I Leave One Unwired?