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electrical:batterycide [2018/06/30 20:58]
frater_secessus [murdering flooded lead-acid]
electrical:batterycide [2023/08/24 22:52] (current)
princess_fluffypants [murdering lithium]
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 +Words of Wisdom:
 +
 +> Over many years of capacity testing hundreds and hundreds of batteries, flooded, GEL and AGM I have yet to see a lead acid battery that could delivers its full storage potential at anything less than 0.75%((C/80)) in tail current at absorption voltage. MaineSail((https://marinehowto.com/how-fast-can-an-agm-battery-be-charged/))
 +
 +
 ====== Battery murder ====== ====== Battery murder ======
  
 //Battery murder// (or //Batterycide//) is the murder of batteries by newbs (new users), poor quality chargers, etc.  The term is commonly used by SternWake:  //"my goal here is to prevent batterycide."//((http://www.cheaprvliving.com/forums/Thread-Intro-Solar-Questions?pid=192042#pid192042)) //Battery murder// (or //Batterycide//) is the murder of batteries by newbs (new users), poor quality chargers, etc.  The term is commonly used by SternWake:  //"my goal here is to prevent batterycide."//((http://www.cheaprvliving.com/forums/Thread-Intro-Solar-Questions?pid=192042#pid192042))
  
-It is so common for new RVers to wreck their first set of house batteries that some recommend using cheap Costco golf cart 6v batteries or [[electrical:12v:deep_cycle_battery#chain_store_batteries|wally world batteries]] as sacrificial lambs to the learning process.((http://www.cheaprvliving.com/forums/Thread-Putting-together-system?pid=176052#pid176052))  As the RVers learns more they would invest in better quality batteries. +It is so common for new RVers to wreck their first set of house batteries that some recommend using cheap [[electrical:12v:deep_cycle_battery#chain_store_batteries|wally world batteries]] as sacrificial lambs to the learning process.((http://www.cheaprvliving.com/forums/Thread-Putting-together-system?pid=176052#pid176052)) As the RVers learns more and gets charging set up correctly they would invest in better quality batteries and have them last several years
  
 ===== murdering flooded lead-acid ===== ===== murdering flooded lead-acid =====
 Flooded lead-acid (FLA) batteries are the most resillient to mistreatment but they too can be killed.   Flooded lead-acid (FLA) batteries are the most resillient to mistreatment but they too can be killed.  
  
-  * leaving them at [[electrical:12v:psoc|partial state of charge]], resulting in //irreversible// sulfation((AKA "hard" sulfation.  The battery undergoes "soft" sulfation and desulfation during normal charging/discharging.)) +  * leaving them at [[electrical:12v:psoc|partial state of charge]], resulting in //irreversible// sulfation((AKA "hard" sulfation.  The battery undergoes "soft" sulfation and desulfation during normal charging/discharging.)) Fully charging each day is optimal.  Fully charging //almost// every day is acceptable
-    * not charging soon enough;  fully charging each day is best.  +  * not charging at [[electrical:solar:charge_controller_setpoints|manufacturer-recommended Absorption voltage]] (Vabs) to reverse normally-occurring ("soft") sulfation. This is most commonly caused by [[electrical:12v:alternator|isolator-only]] charging since the house bank is being charged at ((or slightly below)) alternator voltage. \\ Less commonly, [[electrical:solar|Solar]]-only charging can cause this problem if the [[electrical:solar:sizing|battery capacity is too great for the solar output]].((http://support.rollsbattery.com/support/solutions/articles/5964-battery-sulfation)) 
-    * not charging fully; they need a [[electrical:12v:charging#absorption_stage|long Absorption stage]] at manufacturer-recommended voltage to reverse normally-occurring ("soft") sulfation.((http://support.rollsbattery.com/support/solutions/articles/5964-battery-sulfation))  \\ [[electrical:generator#charging_batteries|Generator-only charging]] can cause this unless the generator runs the necessary number of hours it takes to complete Absorption.  \\ Less commonly, [[electrical:solar|Solar]]-only charging can cause this problem if the [[electrical:solar:sizing|battery capacity is too great for the solar output]]. +  * not holding Vabs for [[electrical:severe_battery_use#increasing_effective_absorption_duration|sufficient duration]] so that absorption current drops to manufacturer-recommended levels. [[electrical:generator#charging_batteries|Generator-]] or  [[electrical:12v:b2b|DC-DC charging]] can cause this unless the charger runs the necessary number of hours it takes to complete Absorption.   
-  * discharging too deeply.  Maximum discharge is typically limited to 50% [[electrical:depth_of_discharge|depth of discharge]].+  * discharging too deeply.  Discharge with lead-chemistries is typically limited to 50% [[electrical:depth_of_discharge|depth of discharge]] as a compromise between cycle life and bank size 
   * allowing the cells to get low on distilled water.  Check them 1x/month or so until you learn their personality.   * allowing the cells to get low on distilled water.  Check them 1x/month or so until you learn their personality.
  
 ===== murdering AGM ===== ===== murdering AGM =====
-AGM have benefits but are easier to murder.+[[opinion:frater_secessus:the_case_for_agm|AGM have benefits]] but are easier to murder.
  
 +  * the lead-acid list above((except the part about low water levels))
   * overvoltage   * overvoltage
     * Incorrect Absorption setpoints.  AGM is commonly Absorped at <= 14.4v while FLA is commonly Absorped higher (at 14.7v-14.8v).  Check your manufacturer's recommendation and do not exceed it.  Overvoltage causes irrepairable damage by outgassing, and AGM cannot be topped off again like FLA.     * Incorrect Absorption setpoints.  AGM is commonly Absorped at <= 14.4v while FLA is commonly Absorped higher (at 14.7v-14.8v).  Check your manufacturer's recommendation and do not exceed it.  Overvoltage causes irrepairable damage by outgassing, and AGM cannot be topped off again like FLA.
-    * Equalization. **Do not equalize AGM**!((lifeline excepted)).     +    * Equalization. **Do not equalize AGM**!((lifeline excepted)).   
-  * the lead-acid list above+  * Low current charging.  Cheap AGM require [[electrical:12v:battery_capacity|C/5]] current minimum in Bulk, and expensive ones require C/3. 
  
  
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-  * overvoltage.  [[electrical:12v:lifepo4_batteries_thread|13.8v is a safe upper limit]] and will charge the bank completely.  Some experienced folk use slightly higher voltages for faster charging but it must be terminated quickly as the bank approaches 100% state of charge. +  * overvoltage.  [[electrical:12v:lifepo4_batteries_thread|13.8v is a safe upper limit]] without BMS and will charge the bank completely.  Some experienced folk use slightly higher voltages for faster charging but it must be terminated quickly as the bank approaches 100% state of charge.  Exception:  Lithium banks with BMS typically overcharge intentionally to balance cells.  The overcharge is consumed by resistors and does not actually go into the cell.   
-  * long periods of 100% state of charge;  cease all charging at 100% and only charge that high if you know some loads will be applied immediately.  Lithium chemistries do not care about partial state of charge so use that to your advantage.+  * long periods of 100% state of charge;  cease all charging at 100% and only charge that high if you know some loads will be applied immediately.   
 +    * IF you're storing the van or know you're not going to be using the batteries for more than a couple days, it's strongly recommended to leave lithium batteries at 50-80% SOC. Lithium chemistries do not care about partial state of charge, and actually prefer it..
   * exposure to high heat   * exposure to high heat
   * attempting to charge at below freezing   * attempting to charge at below freezing
electrical/batterycide.1530406735.txt.gz · Last modified: 2020/10/11 19:48 (external edit)