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--- electrical:12v:deep_cycle_battery [2022/03/15 14:09]
frater_secessus [Lithium chemistries]
+++ electrical:12v:deep_cycle_battery [2024/04/15 01:00] (current)
frater_secessus [Chain Store Batteries]
@@ Line 13: / Line 13: @@
 **Note: This article assumes useage of 12v lead chemistries.** If you're using Lithium, this information is not as applicable.  Please see the [[electrical:12v:drop-in_lifepo4|Drop-in Lithium batteries]] article, or for the more industrious the [[electrical:12v:lifepo4_batteries_thread|Lithium Battery DIY thread]] page
-----
+===== specs =====
+  * Ah (Amp-hours) - the rated [[electrical:12v:battery_capacity|capacity]] of the battery. The basic concept is that a 100Ah battery could theoretically deliver 10A for 10 hours (10A x 10h = 100Ah).  In practice deep cycle batteries are not drained to 0%, and the rate of discharge can affect the apparent capacity.
+  * Wh (Watt-hours) - like Ah above, only multiplied by the nominal voltage.
+    * 100Ah of lead is 1200Wh (100Ah x 12.0v).
+    * 100Ah of LiFePO4 is 1280Wh (100Ah x 12.8v)
+  * cycles - the number of times the battery can be charged and discharged before being considered End Of Life.((EoL is typically considered the point where the battery can no longer produce 80% of its rated output)).    Cycles are usually calculated using a particular [[electrical:12v:battery_capacity|C rate]] and [[electrical:depth_of_discharge|depth of discharge]].
+    * Lead is typically rated at the 1/20th the current as Ah (5A for a 100Ah battery) down to 50% DoD.
+    * LiFePO4 is typically rated at the 1/5th the current as Ah (20A for a 100Ah battery) down to 80% DoD.
+    * both maximum and recommended charge/discharge currents are given [[electrical:12v:battery_capacity|in C]] or Amps.
 ===== Popular Deep-Cycle Lead batteries =====
@@ Line 155: / Line 167: @@
+=== watering FLA ===
+  - check to ensure plates are at least //covered// with liquid
+  - charge fully
+  - check water level again, adding to fill mark
+This order is important because the electrolyte expands a bit as it charges, so filling completely //then// charging could result in spillage and loss of acid.
 ==== VRLA - Valve Regulated Lead Acid ====
@@ Line 186: / Line 204: @@
     * no outgassing under normal conditions
   * CON
-    * generally **double the cost** of FLA for about 20% less capacity((http://www.trojanbattery.com/Tech-Support/FAQ/BatterySelection.aspx))
+    * generally **double the cost** of FLA for similar capacity((http://www.trojanbattery.com/Tech-Support/FAQ/BatterySelection.aspx))
     * Premium AGM need **much more charging current** than flooded, and it may be more than solar-only setups can provide.((http://www.cheaprvliving.com/forums/Thread-How-much-of-an-issue-is-battery-off-gassing?pid=144704#pid144704)) The charging rate given by Lifeline, a respected AGM manufacturer, is //at least// C/5((20A per 100Ah of battery capacity)) or battery life will be affected. They also say it is ok to charge up to 5C((500A per 100Ah of battery capacity!)) (!).((http://lifelinebatteries.com/wp-content/uploads/2015/12/manual.pdf))  Odyssey specifies C/2.5 charging rates for their batteries.((40A per 100Ah of battery capacity))((http://www.odysseybattery.com/documents/ODYSSEY_Battery_Reconditioning_Charge_Procedure.pdf))
     * even cheap AGM require more current than flooded:  minimum C/5, max C/3.(20A-33A per 100Ah of battery capacity).
@@ Line 210: / Line 228: @@
 This type of VRLA battery gelatinizes the electrolyte with SiO2 (silicon dioxide) to stabilize it.  While renowned for their exceptional duty cycle life, they are rarely used in campers due to cost, limited charging max similar to flooded((C/5, https://www.trojanbattery.com/pdf/datasheets/Motive_T1275-AGM_DS.pdf and https://www.qsl.net/wb3gck/gel-cell.htm)), and sensitivity to overvoltage.
-"Lead crystal" batteries may actually be gel, since they claim the electrolyte is made of SiO2.((http://azimuthsolar.ca/getting-silicon-dioxide-sio2-batteries-charging-instructions/)),((https://www.solarpaneltalk.com/forum/solar/the-pros-and-cons-of-solar-energy/22713-why-are-there-no-lead-crystal-battery-distributors-in-the-usa-or-canada?p=272482#post272482))
+=== lead crystal ===
+These appear to be an AGM variant with some gel:
+>> The plate group was taken apart, which showed that the separator is a standard AGM (absorbent glass mat) with double layer. Additionally, a very small amount of gellified electrolyte was found on top of the plates. -- - [[https://www.dropbox.com/s/zz7vf6k8y36btfq/Memo%20%28internal%29%20Betta%20Lead%20Crystal%2026032013.pdf?dl=0|leaked pdf  describing a Betta battery teardown]]
+The "Lead crystal" name appears to refer to the gel component, since manufacturers typical claim the electrolyte is made of SiO2.((http://azimuthsolar.ca/getting-silicon-dioxide-sio2-batteries-charging-instructions/)),((https://www.solarpaneltalk.com/forum/solar/the-pros-and-cons-of-solar-energy/22713-why-are-there-no-lead-crystal-battery-distributors-in-the-usa-or-canada?p=272482#post272482))
@@ Line 256: / Line 280: @@
 Further reading:  [[https://marinehowto.com/what-is-a-deep-cycle-battery/|this page]] with further explanation and teardowns to show the difference between deep cycle and "deep cycle" batteries.
-----
+==== Telco backup batteries ====
+Telcos and other companies that need battery backup rotate their AGM batteries out regularly;  these find their way onto the used market on pallets for relatively low prices.
+These backup batteries are not meant to cycle, vandweller style.  They are designed to live on Float forever then suddently dump their power when grid power goes down.
+Can you make them work for you?  Maybe, but people who can squeeze some use out of them already know what they are doing.

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