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electrical:12v:b2b [2024/03/23 19:40]
frater_secessus [Victron] |
electrical:12v:b2b [2024/03/30 15:12]
frater_secessus [sizing] |
| The DC-DC should be big enough to meet your charging targets given the amount of driving you do and the | The DC-DC should be big enough to meet your charging targets given the amount of driving you do and the |
| contributions of [[electrical:12v:alt_and_solar|other forms of charging]]. It should be small enough that the [[electrical:12v:alternator_details#current|alternator can provide the power continuously]].((Some DC-DC can be derated in the settings in 5A or 10A increments. IOW, you might run your 50A DC-DC at 35A after observing how the system operates.)) **An oversized DC-DC charger cannot protect the alternator**. | contributions of [[electrical:12v:alt_and_solar|other forms of charging]]. It should be small enough that the [[electrical:12v:alternator_details#current|alternator can provide the power continuously]].((Some DC-DC can be derated in the settings in 5A or 10A increments. IOW, you might run your 50A DC-DC at 35A after observing how the system operates.)) **An oversized DC-DC charger cannot protect the alternator**. |
| | |
| | ==== harvest ==== |
| | |
| | Ah = Amps x hours. If your DC-DC charges at 20A and you drive for 2.5 hours it can replace 50Ah (20A x 2.5 hours). |
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| Note that [[opinion:frater_secessus:charging_faster|bigger is not always better]]; different battery chemistries and capacities accept current at different rates. Buying more charging capacity than the battery wants((or should have for its own good, see Li below)) is a waste of money. Buying more charging capacity than your alternator can deliver constantly can overheat/damage the alternator. | Note that [[opinion:frater_secessus:charging_faster|bigger is not always better]]; different battery chemistries and capacities accept current at different rates. Buying more charging capacity than the battery wants((or should have for its own good, see Li below)) is a waste of money. Buying more charging capacity than your alternator can deliver constantly can overheat/damage the alternator. |
| [[https://amzn.to/3entDrt|{{ https://m.media-amazon.com/images/I/51FNDAIhJeS._AC_UY218_.jpg?125}}]] | [[https://amzn.to/3entDrt|{{ https://m.media-amazon.com/images/I/51FNDAIhJeS._AC_UY218_.jpg?125}}]] |
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| Victron makes several DC-DC chargers, some of which are configurable by bluetooth. | Victron makes several DC-DC chargers, some of which are configurable by bluetooth ("Smart" units). |
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| * 50A | * 50A |
| | * all models have BT |
| | * non-isolated only |
| * adds support for "VE.Smart" networking to receive voltage, temperature and current information from [[https://amzn.to/3TMRYga|BMV]] or [[https://amzn.to/498FnIr|SmartShunt]] (voltage and temp only from a [[https://amzn.to/4aoACf1|Smart BatterySense]] since it has no shunt). | * adds support for "VE.Smart" networking to receive voltage, temperature and current information from [[https://amzn.to/3TMRYga|BMV]] or [[https://amzn.to/498FnIr|SmartShunt]] (voltage and temp only from a [[https://amzn.to/4aoACf1|Smart BatterySense]] since it has no shunt). |
| * supports low-temp charging disconnect as sensed by one of the above sensors | * supports low-temp charging disconnect as sensed by one of the above sensors |
