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electrical:solar:status [2019/07/13 20:46] frater_secessus [evening] |
electrical:solar:status [2023/11/19 17:15] frater_secessus [setups with no float] |
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> " | > " | ||
- | >If you want to see lots more amps coming out of the [charge controller], | + | >If you want to see lots more amps coming out of the [charge controller], |
====== Is my solar working? ====== | ====== Is my solar working? ====== | ||
+ | |||
+ | Note: for simplicity' | ||
+ | |||
It is common for those with new solar configurations to worry about whether or not they are working. | It is common for those with new solar configurations to worry about whether or not they are working. | ||
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A **poorly running system** is observed to deliver very little power because it isn't set up right (or is shaded, etc) and can't do any better. | A **poorly running system** is observed to deliver very little power because it isn't set up right (or is shaded, etc) and can't do any better. | ||
- | Also counterintuitively, | + | Also counterintuitively, |
- | This page is to help solar beginners tell what their system is doing without special equipment. | + | This page is to help solar beginners tell what their system is doing without special equipment. |
===== numbers rather than icons or lights ===== | ===== numbers rather than icons or lights ===== | ||
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To tell at a glance what your system is doing you need to find a couple pieces of info about your system. | To tell at a glance what your system is doing you need to find a couple pieces of info about your system. | ||
- | | + | |
+ | {{ https:// | ||
+ | |||
+ | ==== panel specs ==== | ||
+ | |||
+ | The [[electrical: | ||
+ | |||
+ | * **Vmp**, the voltage at which the panel makes max power under laboratory conditions((likely lower in reality)) | ||
+ | * **Voc**, the highest voltage the panel will put out under normal cirumstances. | ||
+ | * when in use, **Vpanel** is the panel voltage reported by the controller. | ||
+ | |||
+ | On the curve pictured at the right Vmp is at the peak of the red voltage line, and Voc is on the far right where output crashes to 0W. | ||
+ | |||
+ | |||
+ | ==== controller ==== | ||
+ | |||
+ | |||
+ | | ||
* **Vfloat** the charge controller' | * **Vfloat** the charge controller' | ||
+ | * **Veq** the charge controller' | ||
If you have an MPPT controller also look up these pieces of info: | If you have an MPPT controller also look up these pieces of info: | ||
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===== then observe the controller ===== | ===== then observe the controller ===== | ||
- | These checks are admittedly crude but will help see if your system is getting it done. No [[electrical: | + | These checks are admittedly crude but will help see if your system is getting it done. No [[electrical: |
For the examples below we will assume the system is set up this way: | For the examples below we will assume the system is set up this way: | ||
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**During bulk charging with MPPT** | **During bulk charging with MPPT** | ||
- | * Vpanel == Vmp | + | * Vpanel == Vmp((although [[electrical: |
* Vbatt climbing toward Vabs | * Vbatt climbing toward Vabs | ||
- | * Current | + | * charge |
- | * **Example: | + | * **Example: |
**During bulk charging with PWM** | **During bulk charging with PWM** | ||
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- | **During Absorption charging | + | **During |
+ | |||
+ | **with MPPT controllers** | ||
* Vpanel starts to creep up from Vmp toward Voc | * Vpanel starts to creep up from Vmp toward Voc | ||
* Vbatt == Vabs until the controller' | * Vbatt == Vabs until the controller' | ||
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* **Example: | * **Example: | ||
- | **During Absorption charging | + | **with PWM controllers** |
- | * Vpanel | + | * Vpanel |
* Controller output decreasing as current demand drops. | * Controller output decreasing as current demand drops. | ||
* the controller may get warmer as current demand drops((percentage of time the PWM circuit is turned OFF increases)) | * the controller may get warmer as current demand drops((percentage of time the PWM circuit is turned OFF increases)) | ||
* **Example: | * **Example: | ||
+ | |||
+ | ==== transitioning to float ==== | ||
+ | |||
+ | When transitioning from Absorption to Float the voltage needs to drop about a volt. The system will " | ||
+ | |||
+ | * Vbatt starts at Vabs | ||
+ | * power harvest is cut off or greatly curtailed (Vpanel spikes toward Voc) | ||
+ | * Vbatt drops to Vfloat | ||
+ | * when Vbatt reaches Vfloat the system will start making power to hold //that// setpoint. | ||
+ | |||
+ | ==== setups with no float ==== | ||
+ | |||
+ | Configurations with no float (" | ||
+ | |||
+ | - charge to the Absorption (" | ||
+ | - **stop charging** | ||
+ | - until voltage falls to the rebulk (" | ||
+ | - repeat | ||
+ | |||
+ | The fall to reBulk looks like the transition to Vfloat described above. In both cases the controller makes no (or practically no) power until the lower setpoint is reached. | ||
+ | |||
+ | === Renogy confusion === | ||
+ | |||
+ | By default Renogy Li profiles work this way, and cause much concern for Renogy users who have not read their manuals and/or who are not familiar with how solar charge controllers / chargers work. [The required information is present [[https:// | ||
+ | |||
+ | * **Rover series** - the table on page 37 of [[https:// | ||
+ | * **DC-DC/ | ||
+ | * **DC-DC charger** (20A/ | ||
+ | * page 18 says " | ||
+ | * there is no setting for Float charge, as shown in the table on page 17 of [[https:// | ||
+ | * page 18 says that Float is for lead only | ||
+ | * the manual does not state the 13.2v boost return setpoint [an egregious error - secessus] | ||
+ | |||
+ | Users uncomfortable with this behavior can set up the USER profile to meet their needs, including defining [[electrical: | ||
+ | |||
==== in float ==== | ==== in float ==== | ||
**During Float with MPPT** | **During Float with MPPT** | ||
- | * Vpanel | + | * Vpanel |
* Vbattery == Vfloat | * Vbattery == Vfloat | ||
* controller output minimal((assuming no loads)) | * controller output minimal((assuming no loads)) | ||
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**During Float with PWM** | **During Float with PWM** | ||
- | * Vpanel | + | * Vpanel |
* controller output minimal((assuming no loads)) | * controller output minimal((assuming no loads)) | ||
* **Example: | * **Example: | ||
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When **adding loads to PWM during absorption (or float)** | When **adding loads to PWM during absorption (or float)** | ||
* Vpanel & Vbatt held at Vabs (or Vfloat) if possible((by reducing the OFF timeslices in the PWM circuit, perhaps until the panel and battery are 100% connected at full output)) | * Vpanel & Vbatt held at Vabs (or Vfloat) if possible((by reducing the OFF timeslices in the PWM circuit, perhaps until the panel and battery are 100% connected at full output)) | ||
- | * If enough power is available no change will be observed but the controller may run cooler | + | * If enough power is available no change will be observed but the controller may run cooler((as PWM switching reduces in frequency.)) |
* If demand outstrips supply the Vbattery & Vpanel will drop((causing a bit of a "death spiral", | * If demand outstrips supply the Vbattery & Vpanel will drop((causing a bit of a "death spiral", | ||
- | * **Example**: | + | * **Example**: |
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==== morning ==== | ==== morning ==== | ||
- | **Are your batteries | + | **Are your batteries at a reasonable |
If not, address this issue soon because discharging too deeply will [[electrical: | If not, address this issue soon because discharging too deeply will [[electrical: | ||
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==== afternoon ==== | ==== afternoon ==== | ||
- | **Are your batteries starting Absorption by noon-ish** and completing Absorption by late afternoon? If so, continue to the next step. | + | **Are your batteries starting Absorption by noon-ish** and completing Absorption by late afternoon?((depending on charging voltage and current Lithium may require no absorption at all to reach 100% SoC)) If so, continue to the next step. |
Note: You can tell your batteries are in Absorption because the bank will be at Vabs, the controller' | Note: You can tell your batteries are in Absorption because the bank will be at Vabs, the controller' | ||
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==== evening ==== | ==== evening ==== | ||
- | **Are you hitting sundown with //at least// 12.6-12.7v((depending on your particular battery)) in your lead acid bank? | + | **Are you hitting sundown with //at least// 12.6-12.7v((depending on your particular battery)) in your lead acid bank?**((~13.2v for LiFePO4)) |
If not, either we are not harvesting enough power or we are using too much. Stop running heavier loads when the controller can no longer hold Vfloat. | If not, either we are not harvesting enough power or we are using too much. Stop running heavier loads when the controller can no longer hold Vfloat. | ||
+ | ===== sudden voltage spikes ===== | ||
+ | |||
+ | If you are seeing sudden voltage spikes and have lithium batteries, you may be seeing [[opinion: | ||
+ | |||
+ | The fix, described in the link above, is to **charge at a lower voltage** that does not antagonize the cells and trip the BMS. | ||
+ | |||
+ | |||
+ | ===== MPPT tracking sweeps ===== | ||
+ | {{ https:// | ||
+ | An **MPPT** controller must sweep the **P**ower **P**oints along the array voltage curve in order to **T**rack the **M**aximum (and non-maxiumum) power points. | ||
+ | Depending on the algorithm the sweep may a small one near presentVpanel, | ||
+ | The sweep will interfere with power production so the mfg attempts to find a balance between | ||
+ | * constant production, and | ||
+ | * learning whether or not one is operating at the optimal power point for present conditions | ||