electrical:12v:drop-in_lifepo4
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electrical:12v:drop-in_lifepo4 [2022/09/15 17:52] frater_secessus [myth: if you don't charge to 14.4v the cells won't balance] |
electrical:12v:drop-in_lifepo4 [2022/10/18 12:13] frater_secessus [myth: you must use DC-DC for alternator charging Li] |
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| Lithium doesn't need Absorption [[electrical:12v:charging#absorption_stage|in the way lead does]]. In some circumstances, however, an Absorption duration can help match [[electrical:solar:charge_controller_setpoints|charging setpoint]] expectations to [[electrical:depth_of_discharge|state of charge]] reality. |
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Lithium doesn't need Absorption [[electrical:12v:charging#absorption_stage|in the way lead does]]. In some circumstances, however, an Absorption duration can help match charging setpoint expectations to state of charge reality. | Most charts and tables showing voltage v. SoC assume moderate rates of charge like 0.2[[electrical:12v:battery_capacity|C]] (20A per 100Ah of capacity). At that rate the charts are reasonably accurate. |
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| **Very high charge rates**, as sometimes seen with [[electrical:12v:drop-in_lifepo4#mythyou_must_use_dc-dc_for_alternator_charging_li|alternator charging]] or large [[electrical:converter|shore power chargers]], can throw off these chart estimates. 0.8C charging might only yield 80% SoC when one expected 90%. Conversely, **very low charge rates** may result in unintentional overcharge; 98% instead of 90%. |
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| One rule of thumb is that the bank is fully charged when you are at your target voltage and current acceptance has decreased to ≤0.10C. |
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FIXME | Further reading: [[https://www.youtube.com/results?search_query=offgrid+garage+absorption|Off-grid Garage videos]] testing various absorption approaches |
==== myth: you can't charge Li with a lead battery charger ==== | ==== myth: you can't charge Li with a lead battery charger ==== |
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=== but that Victron video! === | === but that Victron video! === |
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Why would a manufacturer of pricey [[electrical:12v:b2b|DC-DC chargers]] want to publish [[https://www.youtube.com/watch?v=jgoIocPgOug|a video]] of an LFP pack smoking an alternator?((7:01)) And why would they turn comments off? Oh, right. | Why would a manufacturer of pricey [[electrical:12v:b2b|DC-DC chargers]] want to publish [[https://www.youtube.com/watch?v=jgoIocPgOug|a video]] of a big LFP pack smoking a car alternator?((7:01)) And why would they turn comments off? Oh, right. |
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The setup: | The setup: |
electrical/12v/drop-in_lifepo4.txt · Last modified: 2024/06/19 19:36 by frater_secessus