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electrical:12v:diysmartpass [2023/06/23 15:15]
frater_secessus [20A DC-DC + MOSFET isolator: $224]
electrical:12v:diysmartpass [2024/03/20 16:06] (current)
frater_secessus [DIY Ctek D250 + Smartpass setup]
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 ====== DIY Ctek D250 + Smartpass setup ====== ====== DIY Ctek D250 + Smartpass setup ======
  
-This article is about the Ctek combo and possible approaches to duplicating the major functionality for less money and/or better specs.+This article is about the 1st-gen Ctek combo and possible approaches to duplicating the major functionality for less money and/or better specs.
  
 This article assumes you want and the bank will accept >20A of alternator charging, and that your alternator can handle it.    If you only have a 80Ah AGM then the combo setup is massive overkill.  The bare D250 would handle that with ease.  This article assumes you want and the bank will accept >20A of alternator charging, and that your alternator can handle it.    If you only have a 80Ah AGM then the combo setup is massive overkill.  The bare D250 would handle that with ease. 
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   - stop the isolator from passing voltages >Vfloat from alternator to house bank during Float stage.  This should be a minimal problem with lead batteries((which can usually [[electrical:12v:eternal_absorption|tolerate high floats]])) and with driving times limited to a few hours.    It //could// be a problem with Li batteries and many hours of driving.  Note:  it is not clear that the Ctek combo addresses this issue. The only approaches known to prevent excessive voltage during float are the combo DC-DC and the solenoid + HVD in conservative mode (see below).    - stop the isolator from passing voltages >Vfloat from alternator to house bank during Float stage.  This should be a minimal problem with lead batteries((which can usually [[electrical:12v:eternal_absorption|tolerate high floats]])) and with driving times limited to a few hours.    It //could// be a problem with Li batteries and many hours of driving.  Note:  it is not clear that the Ctek combo addresses this issue. The only approaches known to prevent excessive voltage during float are the combo DC-DC and the solenoid + HVD in conservative mode (see below). 
   - **isolators have no control over current**.  In reality the combo might make **20A+120A** (dead house bank, big alternator, cool temps, Bulk stage) or it might make **20A+1A** (when battery bank is approaching alternator voltage). There is no guarantee that the DC-DC will be making 20A, either.  If your bank is only accepting 15A then having 140A theoretical on tap will not matter.    - **isolators have no control over current**.  In reality the combo might make **20A+120A** (dead house bank, big alternator, cool temps, Bulk stage) or it might make **20A+1A** (when battery bank is approaching alternator voltage). There is no guarantee that the DC-DC will be making 20A, either.  If your bank is only accepting 15A then having 140A theoretical on tap will not matter. 
 +  - provide for [[electrical:12v:self-jumpstarting|self-jumpstarting]].  The method Ctek uses for this appears to be FET-based like main isolation:  "Is a smart combination of relays (actually MOSFETS) that connects starter and service batteries. This enables current from your alternator to charge both batteries".((https://www.ctek.com/storage/5CDB4E293A03CBF6442A620EC8E49CFB548CB48E9BF93425638077279A13BBA1/ac5639c5feaa46d38411ebd69f915b5b/pdf/media/65589cee7d4342e0891e2130149be66f/SmartPass%20120S.pdf))  [Dual MOSFET packs in series? - secesssus]
  
  
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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. 
  
-  * [[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. 
  
  
-==== 20A DC-DC + 20A DC-DC + 20A solar controller + diode isolator: $192-$253 ====+==== 20A DC-DC + 20A solar controller + diode isolator: $192-$253 ====
  
-  * [[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.
  
  
  
-==== 20A DC-DC 20A DC-DC + 20A solar controller + MOSFET isolator: $243-$304 ====+==== 20A DC-DC + 20A solar controller + MOSFET isolator: $243-$304 ====
  
  
-  * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3Aj7NjP|EpEver 20A 100v MPPT]], $80. [[https://amzn.to/3wnJpfE|Victron ArgoFET 200A isolator]] (100A for each "leg", so both starter and house batt get  ≤100A).  $120. +  * MPPT 
- +      * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104.  
-  * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104. [[https://amzn.to/3PMlFIS|HQST 20A PWM]], $19. [[https://amzn.to/3wnJpfE|Victron ArgoFET 200A isolator]] (100A for each "leg", so both starter and house batt get  ≤100A).  $120.+      * [[https://amzn.to/3Aj7NjP|EpEver 20A 100v MPPT]], $80.  
 +      * [[https://amzn.to/3wnJpfE|Victron ArgoFET 200A isolator]] (100A for each "leg", so both starter and house batt get  ≤100A).  $120. 
 +  * PWM 
 +    * [[https://amzn.to/3pCW5eY|Renogy 20A DC-DC]], $104.  
 +    * [[https://amzn.to/3PMlFIS|HQST 20A PWM]], $19.  
 +    * [[https://amzn.to/3wnJpfE|Victron ArgoFET 200A isolator]] (100A for each "leg", so both starter and house batt get  ≤100A).  $120.
  
 ==== 50A DC-DC combo chargers:  $265-$328 ==== ==== 50A DC-DC combo chargers:  $265-$328 ====
electrical/12v/diysmartpass.1687547729.txt.gz · Last modified: 2023/06/23 15:15 by frater_secessus