Differences

This shows you the differences between two versions of the page.

--- electrical:12v:charging [2019/01/03 16:50]
frater_secessus
+++ electrical:12v:charging [2019/05/20 08:57]
frater_secessus [watering batteries] bloop
@@ Line 46: / Line 46: @@
-=== charge-and-hold ===
+===== charge-and-hold =====
 Charging can be achieved with a simpler methods like charge-and-hold where the charger has a single setpoint which it holds;  current will drop as the battery accepts less.
@@ Line 57: / Line 57: @@
-=== charge-and-stop ===
+===== charge-and-stop =====
-[[electrical:solar:charge_controller#shunt_controllers|Shunt chargers]] have a charge-and-stop approach where they:
+[[electrical:solar:charge_controller#shunt_controllers|Shunt]] (on/off) chargers have a charge-and-stop approach where they:
   - charge to [[electrical:12v:hvd|High Voltage Disconnect]] (Vhvd) and stop
   - fall in voltage to a High Voltage Reconnect (Vhvr)
   - repeat
+**This differs from PWM** because PWM can hold an average voltage by cutting power hundreds or thousands of times a second.  If you make a setpoint for 13.6v it will hold 13.6v as long as sun and [[electrical:12v:loads|loads]] cooperate.  A shunt programmed to charge to disconnect at 13.6v and reconnect at 12.7v will average 13.05v.
 These setpoints may or may not be user-configurable.
 Charge-and-stop may be useful when charging battery chemistries like lithium, or when [[electrical:solar:shallow_cycling|shallow-cycling]].
-=== charging AGM batteries ===
+===== charging AGM batteries =====
 AGM batteries are kept healthy by:
-  - vigorous Bulk charging, sometimes greater than solar-only charging can provide.((http://www.cheaprvliving.com/forums/Thread-anyone-familiar-with-Worker-AGM-batteries?pid=97068#pid97068))  Consider augmenting with alternator or shore power charging.
+  - vigorous Bulk charging((minimum current of [[electrical:12v:battery_capacity|C/5]] up to C/3)) sometimes greater than solar-only charging can provide.((http://www.cheaprvliving.com/forums/Thread-anyone-familiar-with-Worker-AGM-batteries?pid=97068#pid97068))  Consider augmenting with alternator or shore power charging.
   - long Absorption stages
   - but lower Absorption voltage (to prevent outgassing)
@@ Line 79: / Line 82: @@
 Many charge controllers have AGM or GEL modes that handle these setpoints and durations.
-=== charging other chemistries ===
+===== charging other chemistries =====
 See [[electrical:12v:lifepo4_batteries_thread#charging|LiFePO4 (lithium) charging]]
-=== equalization ===
+===== equalization =====
 Sometimes called the fourth stage, "equalizing is an overcharge performed after fully charging deep-cycle flooded/wet batteries. An equalizing charge prevents battery stratification and reduces sulfation which are leading causes of battery failure. Trojan recommends equalizing every 30 days or when batteries have a low specific gravity reading after fully charging... Deep-cycle AGM or gel batteries should NEVER be equalized."((http://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf))
@@ Line 92: / Line 95: @@
-Water levels should be topped off //after// equalization.((exposed plates should be covered before EQ, though)) Doing so before equalization could result in spillover.
+If water levels are below the plates, add enough water to cover the plates before equalizing.  Then top off //after// equalization.  Topping off before equalization could result in spillover and loss of electrolyte.
-=== temperature compensation ===
+===== temperature compensation =====
 Accurate charging requires the charger know the temperature of the batteries being charged. In hot temps a full charge will require somewhat lower voltage. Cold temps will require higher voltage((https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/)), enough to trip overvoltage protection in some 12v gear.
@@ Line 108: / Line 111: @@
   - in the absence of actual measurements the charger will likely use the 77F laboratory standard.
-=== watering batteries ====
+===== watering batteries ======
 {{ http://www.trojanbattery.com/wp-content/uploads/2013/07/WaterDia_B.jpg?150}}
 Flooded lead-acid batteries outgas during Absorption, causing a slow loss of water.  They outgas intentionally in Equalization.  To counteract this, the 'dweller must remove the caps and inspect the water level.  If low, distilled water is added.
@@ Line 120: / Line 123: @@
-A [[http://amzn.to/2gEtVwL|battery waterer]] can make the job easier, and does not require one to judge water level visually.
+A [[http://amzn.to/2gEtVwL|battery waterer]] can make the job easier, and does not require one to judge water level visually.  The water "bloops" as it fills and stops blooping when the water is at the correct level.
 Batteries that are older, in poorer health, or are charged at higher voltages will be "thirstier".  Check water levels 1x/month until you know how they behave.
-=== charging while using the 12v system ===
+===== charging while using the 12v system =====
 Smart chargers handle charging under load gracefully. As long as there is enough solar power coming in to hold the absorption or float voltage steady those charging stages will not be disturbed. If there is not enough power to hold the prescribed voltage the charger may restart Bulk charging. This behavior may be configurable by the user.

RV and vandwellers wiki

User Tools

Site Tools

Differences

Page Tools