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electrical:depth_of_discharge [2020/06/10 10:01]
frater_secessus [effect of SoC on battery life]
electrical:depth_of_discharge [2020/06/23 07:55]
frater_secessus
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-===== SoC by amps =====+===== estimatating SoC ===== 
 + 
 +==== SoC by specific gravity ​==== 
 + 
 +> "The truest measure of a [lead chemistry] battery'​s state of charge is the specific gravity of the battery acid." -- Rolls battery.((http://​support.rollsbattery.com/​support/​solutions/​articles/​428-state-of-charge-charging-flooded-lead-acid-batteries)) 
 + 
 +Only flooded-type batteries are practical for SoC assessment by SG of the electrolyte. ​ Needed for this operation:  
 + 
 +  * temperature of the battery 
 +  * SG chart from the battery manufacuturer 
 +  * [[https://​amzn.to/​3dOHGEU|battery SG tester (hydrometer)]] 
 + 
 + 
 + 
 +==== SoC by amps ====
  
 A [[electrical:​12v:​battery_monitor|battery monitor]], usually a amp/coulumb counter with a shunt, will measure the current going to/from the battery. ​ It will often show real-time current flow and a state of charge percentage. ​ It may also show voltage (see below). A [[electrical:​12v:​battery_monitor|battery monitor]], usually a amp/coulumb counter with a shunt, will measure the current going to/from the battery. ​ It will often show real-time current flow and a state of charge percentage. ​ It may also show voltage (see below).
  
 +Note that deep cycle battery [[electrical:​12v:​battery_capacity|capacities]] are given at the "20 hour rate", roughly depleting the battery over the course of a day/night cycle. Heavier loads will cause apparent capacity to decrease. ​ Lithium is much less susceptible and tends to deliver more predictable capacity. ​
  
  
  
-===== SoC by voltage ​=====+ 
 +==== SoC by voltage ====
  
 100% SoC (~12.7v) is measured [[electrical:​12v:​charging|after the bank has been fully charged]] and then rested. It is measured "on the way down"; ​ measuring "on the way up" while charging will lead to false confidence and leaving the battery [[electrical:​12v:​psoc|less than fully charged]]. 100% SoC (~12.7v) is measured [[electrical:​12v:​charging|after the bank has been fully charged]] and then rested. It is measured "on the way down"; ​ measuring "on the way up" while charging will lead to false confidence and leaving the battery [[electrical:​12v:​psoc|less than fully charged]].
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   * constant light loads with measured >=12.2v   * constant light loads with measured >=12.2v
   * intermittent heavier loads that leave the system with measured >=12.2v when that load is removed   * intermittent heavier loads that leave the system with measured >=12.2v when that load is removed
- 
-===== SoC by specific gravity ===== 
- 
-> "The truest measure of a battery'​s state of charge is the specific gravity of the battery acid." -- Rolls battery.((http://​support.rollsbattery.com/​support/​solutions/​articles/​428-state-of-charge-charging-flooded-lead-acid-batteries)) 
- 
-Only flooded-type batteries are practical SoC assessment by SG of the electrolyte. ​ Needed for this operation: ​ 
- 
-  * temperature of the battery 
-  * SG chart from the battery manufacuturer 
-  * [[https://​amzn.to/​3dOHGEU|battery SG tester (hydrometer)]] 
- 
- 
  
  
electrical/depth_of_discharge.txt · Last modified: 2020/08/02 09:55 by frater_secessus