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electrical:12v:diysmartpass [2023/07/28 17:09]
frater_secessus [challenges] |
electrical:12v:diysmartpass [2024/03/20 16:06]
frater_secessus [DIY Ctek D250 + Smartpass setup] |
| ====== DIY Ctek D250 + Smartpass setup ====== | ====== DIY Ctek D250 + Smartpass setup ====== |
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| 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. |
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| 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. |
| - 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 | - 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] |
| 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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