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electrical:12v:charging [2023/01/29 17:53] frater_secessus [Temperature compensation] |
electrical:12v:charging [2023/09/16 12:22] (current) frater_secessus [Collected recommendations] |
**Mythbuster**: bulk charging lead banks with higher current does not necessarily [[opinion:frater_secessus:charging_faster|shorten overall charging time]]. Once minimum charge rates are met, fully charging takes roughly the same amount of time. | **Mythbuster**: bulk charging lead banks with higher current does not necessarily [[opinion:frater_secessus:charging_faster|shorten overall charging time]]. Once minimum charge rates are met, fully charging takes roughly the same amount of time. |
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| === charging current === |
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| Charging current is stated as a fraction of C; 0.1C is 10A for a 100Ah battery. |
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| * Trojan((https://www.trojanbattery.com/resources/battery-maintenance)) |
| * AGM 0.2C |
| * Gel 0.13C |
| * Solar Premium and Signature: 0.13C when charging time is unlimited. "If charging time is limited [like with solar charging], contact Trojan Technical Support for assistance" |
| * Renogy |
| * LiFePO4 0.2C((https://www.renogy.com/content/files/Manuals/RNG-LFP_Manual_V1.0.pdf)) |
| * AGM 0.4C max((https://www.renogy.com/template/files/Specifications/RNG-BATT-AGM12-200.pdf)) unless labeled with 0.3C max |
| * GEL 0.3C((https://www.renogy.com/content/RBT100GEL12-G1/GEL100-Datasheet.pdf)) |
| * Rolls((https://rollsbattery.com/wp-content/uploads/2018/01/Rolls_Battery_Manual.pdf)) |
| * Flooded 0.1C |
| * AGM 0.2C (min 0.1C, max 0.3C) |
| * GEL 0.2C (min 0.1C, max 0.3C) |
| * Lifeline((https://lifelinebatteries.com/wp-content/uploads/2015/12/6-0101F-Lifeline-Technical-Manual-Final-5-06-19.pdf)) |
| * AGM up to 5C inrush, 0.2C minimum((https://marinehowto.com/how-fast-can-an-agm-battery-be-charged/)) |
| * Odyssey((https://www.odysseybatteries.com/odyssey/docs/us-ody-tm.pdf)) |
| * AGM 0.4C minimum, no maximum |
| * EastPenn/Deka - 0.3C max((https://www.eastpennmanufacturing.com/wp-content/uploads/Renewable-Energy-Charging-Parameters-1913.pdf)) - |
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==== Absorption stage ==== | ==== Absorption stage ==== |
The absorption stage, sometimes called //acceptance//((which makes sense)) or //boost//((doesn't make sense!)), is a constant voltage stage during which the battery is brought to full charge. This stage requires a **great deal of time** but decreasing amounts of current. | The absorption stage, sometimes called //acceptance//((which makes sense)) or //boost//((doesn't make sense!)), is a constant voltage stage during which the battery is brought to full charge. This stage requires a **great deal of time** but decreasing amounts of current. |
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Absorption **begins when the battery reaches the absorption voltage** ([[electrical:12v:electrical notation|Vabs]], 14.8v in our example) and **ends when the battery tapers off current acceptance** to something like [[electrical:12v:battery_capacity|C/100]] ("End Absorb", "endAmps"), and/or when a period of time has elapsed. | Absorption **begins when the battery reaches the absorption voltage** ([[electrical:12v:electrical notation|Vabs]], 14.8v in our example) and **ends when the battery tapers off current acceptance**((that the battery is taking from the charging source)) to something like [[electrical:12v:battery_capacity|C/100]] to C/50((1A-2A per 100AH of capacity)) ("tail current", "End Absorb", "endAmps"), and/or when a period of time has elapsed. |
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Example: if you have a 100Ah battery bank and the manufacturer states that endAmps is C/100, then the battery is fully charged when it is only accepting 1A of current((100Ah/100 = 1A)) **at Vabs**. An endAmps recommendation of C/200 would be the battery accepting 0.5A of current.((100Ah/200 = 0.5A)) at Vabs. | Example: if you have a 100Ah battery bank and the manufacturer states that endAmps is C/100, then the battery is fully charged when it is only accepting 1A of current((100Ah/100 = 1A)) **at Vabs**. An endAmps recommendation of C/200 would be the battery accepting 0.5A of current.((100Ah/200 = 0.5A)) at Vabs. |
- Float voltage - Li does not like to sit at 100% SoC,((the cells degrade faster at 100%+ SoC)) so a float voltage in the 13s allows them to come down off the peak and rest at a healthier voltage for them while still holding useful capacity. | - Float voltage - Li does not like to sit at 100% SoC,((the cells degrade faster at 100%+ SoC)) so a float voltage in the 13s allows them to come down off the peak and rest at a healthier voltage for them while still holding useful capacity. |
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Also see [[electrical:12v:lifepo4_batteries_thread#charging|LiFePO4 (lithium) bare cell charging]]. | Also see [[electrical:12v:lifepo4_batteries_thread#charging|LiFePO4 (lithium) bare cell charging]] and [[electrical:12v:drop-in_lifepo4#an_approach_to_greater_longevity|thoughts about charging LFP gently]]. |
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===== Equalization ===== | ===== Equalization ===== |
| Interstate GC2((https://www.interstatebatteries.com/support/golf-cart-battery-installation-and-maintenance)) | Min C/10 \\ Max C/7.7((.13C))\\ Vabs 14.8v\\ Vfloat 13.5v\\ Veq 16.2v | | | | | | Interstate GC2((https://www.interstatebatteries.com/support/golf-cart-battery-installation-and-maintenance)) | Min C/10 \\ Max C/7.7((.13C))\\ Vabs 14.8v\\ Vfloat 13.5v\\ Veq 16.2v | | | | |
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| ====== further reading ====== |
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| * [[https://web.archive.org/web/20150919125248/https://c34.org/bbs/index.php/topic,8216.0.html|Why going to float is NOT full]] |
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