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electrical:12v:alternator [2024/04/05 11:08]
frater_secessus [gotchas] |
electrical:12v:alternator [2024/04/05 11:10]
frater_secessus [gotchas] |
| * On ignition-triggered((IGN, D+)) setups **if the key is turned to ACC but the engine not started a depleted house battery can pull down the starter battery**. Workarounds: use a VSR, a DC delay timer, a DC-DC charger, or start the vehicle immediately after inserting the key((ie, do not leave in the Accessory position which would drain the starter battery)). | * On ignition-triggered((IGN, D+)) setups **if the key is turned to ACC but the engine not started a depleted house battery can pull down the starter battery**. Workarounds: use a VSR, a DC delay timer, a DC-DC charger, or start the vehicle immediately after inserting the key((ie, do not leave in the Accessory position which would drain the starter battery)). |
| * Solar charging while the engine is running may [[opinion:frater_secessus:alternatorSolarStall|get "stuck" at alternator voltage]]. Workaround: higher solar wattage, DC-DC charger, or diode/FET-based isolator, or a switch to disconnect isolator after alternator voltage is reached. The [[https://amzn.to/3h5iMUd|Victron Cyrix-ct isolator]] could be useful here, as it appears to disconnect >13.8v.((https://www.victronenergy.com/upload/documents/Datasheet-Cyrix-ct-120A-230A-EN.pdf)) | * Solar charging while the engine is running may [[opinion:frater_secessus:alternatorSolarStall|get "stuck" at alternator voltage]]. Workaround: higher solar wattage, DC-DC charger, or diode/FET-based isolator, or a switch to disconnect isolator after alternator voltage is reached. The [[https://amzn.to/3h5iMUd|Victron Cyrix-ct isolator]] could be useful here, as it appears to disconnect >13.8v.((https://www.victronenergy.com/upload/documents/Datasheet-Cyrix-ct-120A-230A-EN.pdf)) |
| * Alternator charging may bring some battery chemistries (like bare lithium cells with no BMS) to **unsuitably high voltages**. Workarounds: A [[electrical:12v:hvd|high voltage disconnect]] can [[electrical:12v:alternator charging hvd|restrict alternator charging to lower voltages]]. [[electrical:12v:b2b|DC-DC chargers]] can also regulate voltage provided to the house battery. | * Alternator charging may bring some battery chemistries (like bare lithium cells with no BMS) to **unsuitably high voltages**. Workarounds: A [[electrical:12v:hvd|high voltage disconnect]] can [[electrical:12v:alternator charging hvd|restrict alternator charging to lower voltages]]. And [[electrical:12v:b2b|DC-DC chargers]] can also regulate voltage provided to the house battery. |
| * It is possible for a plain combiner to "mask" the symptoms of a failing starter battery since the house bank would be assisting with the start. | * It is possible for a plain combiner to "mask" the symptoms of a failing starter battery since the house bank would be assisting with the start. It is also possible for powerful solar to mask symptoms of a dying alternator because in that case the solar is helping run the chassis electricals. |
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| ===== disabling alternator charging ===== | ===== disabling alternator charging ===== |
