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// (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 [[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 =====
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.)) Fully charging each day is optimal.  Fully charging //almost// every day is acceptable.
  * 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 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.  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.

===== murdering AGM =====
[[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
    * 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)).  
  * Low current charging.  Cheap AGM require [[electrical:12v:battery_capacity|C/5]] current minimum in Bulk, and expensive ones require C/3.




===== murdering lithium =====


  * 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.  
    * 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
  * attempting to charge at below freezing
  * poor quality BMS
  * high [dis]charge rates without BMS