electrical:12v:voltage_sag
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electrical:12v:voltage_sag [2022/03/16 13:34] frater_secessus [Voltage sag] |
electrical:12v:voltage_sag [2022/03/16 13:38] frater_secessus [do nothing] |
Extreme example: During heavy charging the controller might see 14v instead of the battery's 13v. This 14v -> 13v difference is called voltage sag. A similar thing happens in reverse when consuming power. The battery might be 12.5v but an inverter running a big load might "see" 11.5v at its own terminals and shut off prematurely.((from the user's point of view)). It also makes it difficult to assess [[electrical:depth_of_discharge|state of charge]] of lead batteries by voltage. | Extreme example: During heavy charging the controller might see 14v instead of the battery's 13v. This 14v -> 13v difference is called voltage sag. A similar thing happens in reverse when consuming power. The battery might be 12.5v but an inverter running a big load might "see" 11.5v at its own terminals and shut off prematurely.((from the user's point of view)). It also makes it difficult to assess [[electrical:depth_of_discharge|state of charge]] of lead batteries by voltage. |
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Sag presents special challenges when charging [[electrical:12v:drop-in_lifepo4|lithium]] battery banks, since the majority of their usable power found in a **very narrow range** only about 0.5v wide. Voltage sag when charging with lithium can result in unpredictable/inconsistent charging. | Sag presents special challenges when charging [[electrical:12v:drop-in_lifepo4|lithium]] battery banks. Since the majority of lithium's usable power is found in an **extremely narrow voltage range**((about 0.5v wide)) sag can result in wildly unpredictable/inconsistent charging. |
===== approaches ===== | ===== approaches ===== |
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This is the majority position since most are unaware of the issue, or don't judge it to be important. And it may //not// be a problem since since | This is the majority position since most are unaware of the issue, or don't judge it to be important. And it may //not// be a problem since since |
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- solar-only charging is often low-current charging, minimizing sag | - solar-only charging is often low-current charging, minimizing charge-induced sag |
- lead-chemistry batteries often have a range of Absorption and Float [[electrical:solar:charge_controller_setpoints|setpoints]] (see below) | - lead-chemistry batteries often have a range of Absorption and Float [[electrical:solar:charge_controller_setpoints|setpoints]] (see below) |
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electrical/12v/voltage_sag.txt ยท Last modified: 2024/03/10 13:58 by frater_secessus