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electrical:12v:diysmartpass [2022/09/10 13:26] frater_secessus [how it works] |
electrical:12v:diysmartpass [2023/06/23 15:18] frater_secessus [20A DC-DC + 20A DC-DC + 20A solar controller + diode isolator: $192-$253] |
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>> There are no solutions. There are only trade-offs. ― Thomas Sowell | >> There are no solutions. There are only trade-offs. ― Thomas Sowell |
==== 20A combo DC-DC + isolator: $172 ==== | ==== 20A DC-DC + isolator: $172 ==== |
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This is the simplest and cheapest option, but requires ingenuity to keep boosted voltage from leaking back to the chassis. In this case the isolator (solenoid) is turned off by the HVD at Vfloat (conservative) or just below alternator voltage (power-maximizing). | This is the simplest and cheapest option, but requires ingenuity to keep boosted voltage from leaking back to the chassis. In this case the isolator (solenoid) is turned off by the HVD at Vfloat (conservative) or just below alternator voltage (power-maximizing). |
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* [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3QGwihC|Cole-Hersee continuous duty solenoid]], $55. [[https://amzn.to/3AhdNti|High voltage disconnect]], $13. | * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. |
| * [[https://amzn.to/3QGwihC|Cole-Hersee continuous duty solenoid]], $55. |
| * [[https://amzn.to/3AhdNti|High voltage disconnect]], $13. |
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The HVD mentioned here is actually LVD/HVD. You can use it to make the isolator a [[electrical:12v:alternator#voltage-sensing_relays|VSR]], turning on at 13.2v (engine running) and turning off at just under alternator voltage, if Valt > Vfloat.((and it probably is)) Alternatively, the HVD might turn off >Vfloat. | The HVD mentioned here is actually LVD/HVD. You can use it to make the isolator a [[electrical:12v:alternator#voltage-sensing_relays|VSR]], turning on at 13.2v (engine running) and turning off at just under alternator voltage, if Valt > Vfloat.((and it probably is)) Alternatively, the HVD might turn off >Vfloat. |
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==== 20A combo DC-DC + diode isolator: $173 ==== | ==== 20A DC-DC + diode isolator: $173 ==== |
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This option is requires no HVD, but has two possible drawbacks: | This option is requires no HVD, but has two possible drawbacks: |
- drop of ~0.5v. Perhaps not a big issue since the DC-DC is boosting. | - drop of ~0.5v. Perhaps not a big issue since the DC-DC is boosting. |
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* [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3T9JKft|Cole-Hersee 90A diode isolator]], $69. | * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. |
| * [[https://amzn.to/3T9JKft|Cole-Hersee 90A diode isolator]], $69. |
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==== 20A combo DC-DC + MOSFET isolator: $224 ==== | ==== 20A DC-DC + MOSFET isolator: $224 ==== |
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Same technology as the Smartpass. | Same technology as the Smartpass. |
Similar to the diode isolator setup above, but with MOSFETS instead of diodes. This means no((or minimal)) voltage drop. | Similar to the diode isolator setup above, but with MOSFETS instead of diodes. This means no((or minimal)) voltage drop. |
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* [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3wnJpfE|Victron ArgoFET 200A isolator]] (100A for each "leg", so both starter and house batt get ≤100A). $120. | * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. |
| * [[https://amzn.to/3wnJpfE|Victron ArgoFET 200A isolator]] (100A for each "leg", so both starter and house batt get ≤100A). $120. |
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The main benefit of a separate MPPT is we get to normal PV input limits, 100v+. We also may have more control. One can also drastically reduce cost by using PWM with nominal 12v panels, or using MPPT with cheap used higher-voltage panels. | The main benefit of a separate MPPT is we get to normal PV input limits, 100v+. We also may have more control. One can also drastically reduce cost by using PWM with nominal 12v panels, or using MPPT with cheap used higher-voltage panels. |
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* [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3Aj7NjP|EpEver 20A 100v MPPT]], $80. [[https://amzn.to/3QGwihC|Cole-Hersee continuous duty solenoid]], $55. [[https://amzn.to/3AhdNti|High voltage disconnect]], $13. | * MPPT |
* [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3PMlFIS|HQST 20A PWM]], $19. [[https://amzn.to/3QGwihC|Cole-Hersee continuous duty solenoid]], $55. [[https://amzn.to/3AhdNti|High voltage disconnect]], $13. | * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. |
| * [[https://amzn.to/3Aj7NjP|EpEver 20A 100v MPPT]], $80. |
| * [[https://amzn.to/3QGwihC|Cole-Hersee continuous duty solenoid]], $55. |
| * [[https://amzn.to/3AhdNti|High voltage disconnect]], $13. |
| * PWM |
| * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. |
| * [[https://amzn.to/3PMlFIS|HQST 20A PWM]], $19. |
| * [[https://amzn.to/3QGwihC|Cole-Hersee continuous duty solenoid]], $55. |
| * [[https://amzn.to/3AhdNti|High voltage disconnect]], $13. |
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==== 20A DC-DC + 20A DC-DC + 20A solar controller + diode isolator: $192-$253 ==== | ==== 20A DC-DC + 20A solar controller + diode isolator: $192-$253 ==== |
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* [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3Aj7NjP|EpEver 20A 100v MPPT]], $80. [[https://amzn.to/3T9JKft|Cole-Hersee 90A diode isolator]], $69. | * MPPT |
* [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3PMlFIS|HQST 20A PWM]], $19. [[https://amzn.to/3T9JKft|Cole-Hersee 90A diode isolator]], $69. | * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. |
| * [[https://amzn.to/3Aj7NjP|EpEver 20A 100v MPPT]], $80. |
| * [[https://amzn.to/3T9JKft|Cole-Hersee 90A diode isolator]], $69. |
| * PWM |
| * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. |
| * [[https://amzn.to/3PMlFIS|HQST 20A PWM]], $19. |
| * [[https://amzn.to/3T9JKft|Cole-Hersee 90A diode isolator]], $69. |
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