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electrical:12v:drop-in_lifepo4 [2022/06/16 23:08] frater_secessus [myth: you have to charge Li to 100%] |
electrical:12v:drop-in_lifepo4 [2022/07/04 13:09] frater_secessus [myth: you must use DC-DC for alternator charging Li] |
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- Read and understand your isolator' | - Read and understand your isolator' | ||
- observe your vehicle' | - observe your vehicle' | ||
- | - decide whether this will work for your alternator, your isolator, and your Li battery | + | - make a first approximation about the ability of alternator, your isolator, and your Li battery |
- install [[electrical: | - install [[electrical: | ||
- make the first test run a brief one and with the Li fairly well charged.((higher states of charge will typically lessen current demands to some degree)) | - make the first test run a brief one and with the Li fairly well charged.((higher states of charge will typically lessen current demands to some degree)) | ||
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* cell 2 = 3.400v | * cell 2 = 3.400v | ||
* cell 3 = 3.400v | * cell 3 = 3.400v | ||
- | * cell 4 = 3.**500v** <-- balancer will try to slow this one down | + | * cell 4 = 3.**500v** < |
In both cases the overall battery voltage is 13.6v, but in the unbalanced battery cell #1 is lagging (reducing capacity) and cell #4 is too high. The balancer will attempt to rein in #4 but the effect is tiny. Using a typical balancing current of 50mA, if you are charging at 20A that means the cells are receiving 5A except cell #4 which gets only 4.95A, about a 1% difference. | In both cases the overall battery voltage is 13.6v, but in the unbalanced battery cell #1 is lagging (reducing capacity) and cell #4 is too high. The balancer will attempt to rein in #4 but the effect is tiny. Using a typical balancing current of 50mA, if you are charging at 20A that means the cells are receiving 5A except cell #4 which gets only 4.95A, about a 1% difference. |