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electrical:12v:directcharginglfp

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electrical:12v:directcharginglfp [2022/10/12 18:33]
frater_secessus [analysis of van-relevant installs] 		electrical:12v:directcharginglfp [2022/11/05 12:29]
frater_secessus [Isolator charging LiFePO4 banks]
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   - **overcharging** (holding Vabs after reaching 100% SoC) is actually a bigger concern, particularly if one drives for hours.  A manual switch on the isolator (D+ for solenoids, on the ground wire for VSR) will allow the owner to disable alternator charging at will.    - **overcharging** (holding Vabs after reaching 100% SoC) is actually a bigger concern, particularly if one drives for hours.  A manual switch on the isolator (D+ for solenoids, on the ground wire for VSR) will allow the owner to disable alternator charging at will. 
  
-So this article will focus on current demand by LiFePO4 house banks.+This article will focus on current demand by LiFePO4 house banks.
  
 ===== the formula in 60 seconds ===== ===== the formula in 60 seconds =====
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   - Read and understand your Li battery manufacturer's charging specs - undercharging is fine((assuming one stays above 20% State of Charge)); overcharging is less so but is relatively rare in an isolator context.   - Read and understand your Li battery manufacturer's charging specs - undercharging is fine((assuming one stays above 20% State of Charge)); overcharging is less so but is relatively rare in an isolator context.
   - Read and understand your alternator's specs   - Read and understand your alternator's specs
 +  - measure how much current from the alternator your vehicle requires to run its own loads.  Since alternators can, //while driving//, run continuous current ~1/2 of their rating this means the bank can use (ALTERNATOR RATING / 2) - VEHICLE LOADS.  If your bank wants to pull more than that an appropriately-sized DC-DC may be required. 
   - Read and understand your isolator's specs and functionality   - Read and understand your isolator's specs and functionality
   - observe your vehicle's chassis voltage during normal operation - note that the voltage //at the battery's location// will likely be lower due to long wiring and also lower when the wiring is carrying a hefty charging current.     - observe your vehicle's chassis voltage during normal operation - note that the voltage //at the battery's location// will likely be lower due to long wiring and also lower when the wiring is carrying a hefty charging current.  
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   - 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))((if you have paralleled batteries you might want to do this step with just one in place to get a feel for the draw.))  Start the engine and see if the charging current and voltage is acceptable.  Turn off the engine.   - 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))((if you have paralleled batteries you might want to do this step with just one in place to get a feel for the draw.))  Start the engine and see if the charging current and voltage is acceptable.  Turn off the engine.
   - test it with a drive.   - test it with a drive.
-  - repeat the last two steps with the Li bank at lower and lower states of charge, down to the lowest expected state of charge you expect to recharge from alternator.+  - repeat the last two steps with the Li bank at lower and lower states of charge, down to the lowest state of charge you expect to recharge from alternator.
   - disconnect the isolator with a switch when you come to the desired SoC   - disconnect the isolator with a switch when you come to the desired SoC
  
electrical/12v/directcharginglfp.txt ยท Last modified: 2024/04/04 11:51 by frater_secessus

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