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electrical:12v:directcharginglfp [2022/09/17 18:12] frater_secessus [current drawn expressed as C-rate] |
electrical:12v:directcharginglfp [2022/10/12 18:33] frater_secessus [analysis of van-relevant installs] |
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* standard regulators (no external regulators, internal regulator hacks, etc) | * standard regulators (no external regulators, internal regulator hacks, etc) | ||
* with rated capacities ≥120A((where stated)) | * with rated capacities ≥120A((where stated)) | ||
+ | * plain isolators, not voltage-boosting [[electrical: | ||
Since it includes screenshots the data will be for installs documented before Sept 15, 2022. | Since it includes screenshots the data will be for installs documented before Sept 15, 2022. | ||
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- | On average, direct-charging 100Ah of LFP consumed ~22% of the alternator' | + | On average, direct-charging |
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=== lessons === | === lessons === | ||
- | Don' | + | Think twice about |
Do not idle to charge. | Do not idle to charge. | ||
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* you **already own a DC-DC** | * you **already own a DC-DC** | ||
- | * you **need consistent, predictable charging**, like 40A over the next hour. DC-DC will provide this((barring interference from big chassis loads, BMS protections, | + | * you **need consistent, predictable charging**, like 40A over the next hour. DC-DC will provide this((barring interference from big chassis loads, BMS protections, |
* you **don' | * you **don' | ||
- | * choosing wiring can require some effort | + | |
* [[electrical: | * [[electrical: | ||
* **if isolator wiring is already present** from a previous bank, test it while using a monitor or BMS info to watch actual current. | * **if isolator wiring is already present** from a previous bank, test it while using a monitor or BMS info to watch actual current. | ||
* **if starting from scratch** there is less to go on. | * **if starting from scratch** there is less to go on. | ||
- | * In the van-relevant examples above LFP banks typically pull 0.33C, or 33A per 100Ah of capacity. | + | |
- | * LFP manufacturers typically allow up to 0.5C charging for normal use. | + | |
+ | * a set of heavy jumper cables and a clamp-on monitor | ||
If you are still interested, here is one approach to assessing your setup for direct charging lithium: | If you are still interested, here is one approach to assessing your setup for direct charging lithium: |