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--- electrical:solar:status [2023/09/02 12:25]
frater_secessus [first collect a few numbers]
+++ electrical:solar:status [2024/01/14 15:32] (current)
frater_secessus [setups with no float]
@@ Line 43: / Line 43: @@
   * **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.  At Voc the panel produces no current and therefore no power (Voc x 0A = 0W)
+  * when in use, **Vpanel** is the panel voltage reported by the controller.  PWM controllers might not report this value.
 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.
@@ Line 123: / Line 124: @@
 ==== setups with no float ====
-Configurations with no float ("charge and stop", found on some Lithium profiles) will stop charging then fall all the way to the reBulk/reBoost setpoint.  At that point they begin charging again.
+Configurations with no float ("charge and stop", found on some Lithium profiles) will
+  - charge to the Absorption ("boost") setpoint((with or without some amount of Absorption duration))
+  - **stop charging**
+  - until voltage falls to the rebulk ("reboost", "boost return voltage") setpoint
+  - repeat
+The fall to reBulk looks like the transition to Vfloat [[electrical:solar:status#transitioning_to_float|described above]]. In both cases the controller makes no (or practically no) power until the lower setpoint is reached.
+A constant cycling 14.4v->13.2v->14.4v might seem extreme but in practice there is little actual cycling occurring.  A fully-charged 4S LFP with no loads will rest somewhere around **13.6v**. So for actual SoC changes we are talking about the difference between 13.6v and 13.2v.  With significant loads applied 13.2v observed could mean SoC as high as 90% and with trivial loads as low as 70%.((with trivial loads there might be only 1 cycle a day since voltage would not fall to reBoost))  In normal use the real cycling might be 100%->85%-100% and the solar is helping carry the loads during charging periods.
+=== 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://www.renogy.com/support/downloads|in the manuals]] but Renogy really should spell it out for first-timers. -- secessus]
+  * **Rover series** - the table on page 37 of [[https://www.renogy.com/content/RNG-CTRL-RVR40/RVR203040-Manual.pdf|the manual]] shows there is no boost duration and no float in the Li profile.  The "boost return voltage" field shows **13.2v**.
+  * **DC-DC/MPPT combo charger** - the table on page 2 of [[https://www.renogy.com/content/RBC3050D1S-G1/RBC3050D1S-Manual.pdf|the manual]] shows there is no boost duration and no float in the Li profile.  The "boost return voltage" field shows **13.2v**.
+  * **DC-DC charger** (20A/40A/60A)
+    * page 18 says "lithium batteries will only have an absorption charge and no float charge"
+    * there is no setting for Float charge, as shown in the table on page 17 of [[https://www.renogy.com/content/RNG-DCC1212-60-BC/DCC1212-204060-Manual.pdf|the manual]] and it says "for lithium... there will not be a float voltage"
+    * 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:12v:drop-in_lifepo4#mythyou_shouldn_t_float_lithium|a quasi-Float setpoint]].((low temp charging cutoff, when available, may only be available in canned Li profiles))
-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.
 ==== in float ====

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