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electrical:12v:alternator [2021/04/03 13:18]
frater_secessus [gotchas] |
electrical:12v:alternator [2021/05/20 12:50]
frater_secessus [voltage-sensing relays] |
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| ((http://www.cheaprvliving.com/forums/Thread-Questions-about-continuous-duty-solenoid?pid=229761#pid229761)). SternWake recommends the [[http://amzn.to/2fZLFzs|Blue Sea 9012]]((http://www.cheaprvliving.com/forums/Thread-Questions-about-continuous-duty-solenoid?pid=229761#pid229761)) although [[https://amzn.to/2NLVwg0|non-marine units in the $20-$50 range]] are more common in vans. \\ Solenoids can be used for [[electrical:12v:self-jumpstarting|self-jumpstarting]] //if// the chassis battery has enough juice to engage the solenoid. | ((http://www.cheaprvliving.com/forums/Thread-Questions-about-continuous-duty-solenoid?pid=229761#pid229761)). SternWake recommends the [[http://amzn.to/2fZLFzs|Blue Sea 9012]]((http://www.cheaprvliving.com/forums/Thread-Questions-about-continuous-duty-solenoid?pid=229761#pid229761)) although [[https://amzn.to/2NLVwg0|non-marine units in the $20-$50 range]] are more common in vans. \\ Solenoids can be used for [[electrical:12v:self-jumpstarting|self-jumpstarting]] //if// the chassis battery has enough juice to engage the solenoid. |
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| | [[electrical:12v:voltage sensing delay|Voltages-sensing (delay)]] can be added to solenoids. |
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| ==== voltage-sensing relays ==== | ==== voltage-sensing relays ==== |
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| [[https://amzn.to/2Ri2jQV|{{ https://images-na.ssl-images-amazon.com/images/I/418qcncjT0L._AC_US218_.jpg|}}]]voltage sensing relays are solenoids with a bit of extra logic to know when to connect/disconnect. The VSR does not get trigger voltage from the fuse panel but rather reads the voltages of one((vsr)) or both))dvsr)) batteries to know when to switch on. \\ This kind of isolator may have a "combine" override function to enable self-jumpstarting. | [[https://amzn.to/2Ri2jQV|{{ https://images-na.ssl-images-amazon.com/images/I/418qcncjT0L._AC_US218_.jpg|}}]]voltage sensing relays (VSR, also called Automatic Charging Relays or ACR) are solenoids with a bit of extra logic to know when to connect/disconnect. The VSR does not get trigger voltage from the fuse panel but rather reads the voltages of one((vsr)) or both))dvsr)) batteries to know when to switch on. \\ This kind of isolator may have a "combine" override function to enable self-jumpstarting. |
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| | > in its simplest form, all an ACR really does is parallel batteries when charging is present and un-parallel batteries when there is no charging present. It does this automatically with no human forgetfulness.((https://marinehowto.com/automatic-charging-relays/)) |
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| - [[http://amzn.to/2h2tDxp|single voltage sensing]] - this type reads the voltage of only one battery. In the case of an RV it would read the voltage of the starting battery. When it is high enough above resting voltage (ie, being charged by alternator) it connects the starting and house batteries. \\ [secessus says: "IMO the practical benefit (if any) to charging the starter battery "first" is keeping the load on the alternator reasonable. In practice, the isolator generally connects the two within a few seconds."] \\ Examples: [[http://amzn.to/2h2tDxp|Sure Power 1314]], [[https://amzn.to/2tEGp1e|BlueSea BatteryLink]], [[https://amzn.to/2Ri2jQV|Battery Doctor]]. | - [[http://amzn.to/2h2tDxp|single voltage sensing]] - this type reads the voltage of only one battery. In the case of an RV it would read the voltage of the starting battery. When it is high enough above resting voltage (ie, being charged by alternator) it connects the starting and house batteries. \\ [secessus says: "IMO the practical benefit (if any) to charging the starter battery "first" is keeping the load on the alternator reasonable. In practice, the isolator generally connects the two within a few seconds."] \\ Examples: [[http://amzn.to/2h2tDxp|Sure Power 1314]], [[https://amzn.to/2tEGp1e|BlueSea BatteryLink]], [[https://amzn.to/2Ri2jQV|Battery Doctor]]. |
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| * Solar charging while the isolator circuit is closed (ie, batteries connected) can pass higher-than-normal voltage to the chassis and starter battery. Workaround: see notes on HVD and DC-DC charging below. | * Solar charging while the isolator circuit is closed (ie, batteries connected) can pass higher-than-normal voltage to the chassis and starter battery. Workaround: see notes on HVD and DC-DC charging below. |
| * Voltage-sensing relays can be unintentionally triggered((dVSR)) or "held closed"((both VSR and dVSR)) [[http://bdp.mousetrap.net/index.php/2018/10/27/side-effect-of-solar-alternator-charging/|by voltage from the solar-charged side]] in some scenarios. Workaround: address with HVD as below if desired, or with a DC-DC charger triggered by ignition rather than by chassis voltage. | * Voltage-sensing relays can be unintentionally triggered((dVSR)) or "held closed"((both VSR and dVSR)) [[http://bdp.mousetrap.net/index.php/2018/10/27/side-effect-of-solar-alternator-charging/|by voltage from the solar-charged side]] in some scenarios. Workaround: address with HVD as below if desired, or with a DC-DC charger triggered by ignition rather than by chassis voltage, or by putting a switch on the trigger wire. |
| * **Idling the engine** to charge house batteries **can overheat the alternator**,particularly older-style ones that do not reduce output to control high temps. Workaround: Don't plan to idle to charge from alternator. If you do, a fan may help cool the alternator. | * **Idling the engine** to charge house batteries **can overheat the alternator**,particularly older-style ones that do not reduce output to control high temps. Workaround: Don't plan to idle to charge from alternator. If you do, a fan may help cool the alternator. |
| * In early morning when house battery voltage is lowest, **a plain solenoid may unintentionally allow depleted batteries to pull down the starter battery**. Workarounds: use a VSR, or start the vehicle immediately after inserting the key((ie, do not leave in the Accessory position which would drain the starter battery)). | * In early morning when house battery voltage is lowest, **a plain solenoid may unintentionally allow depleted batteries to pull down the starter battery**. Workarounds: use a VSR, or start the vehicle immediately after inserting the key((ie, do not leave in the Accessory position which would drain the starter battery)). |
