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electrical:12v:deep_cycle_battery

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electrical:12v:deep_cycle_battery [2018/12/28 08:47]
frater_secessus [lithium chemistries] corrected li-ion discharge voltages 		electrical:12v:deep_cycle_battery [2018/12/28 14:29]
frater_secessus [Non-LiFePO4 lithium-ion]
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 ==== Non-LiFePO4 lithium-ion ==== ==== Non-LiFePO4 lithium-ion ====
  
-Non-LiFeP04 Li-ion [called "li-ion" hereafter] are usually built in [[electrical:12v:parallel_serial|3S configuration]] and so run lower voltages than LFP or lead.  Usable cell voltage is 4.2v - 3v, yielding bank voltage of **12.6v - 9v**.  This lower voltage may trip [[electrical:12v:lvd|Low Voltage Disconnect]] on [[electrical:inverter|inverters]] or [[food:refrigeration|refrigerators]]. +Non-LiFeP04 Li-ion [called "li-ion" hereafter] are usually built in [[electrical:12v:parallel_serial|3S configuration]] and so run lower voltages than LFP or lead.  Usable cell voltage is 4.2v - 3v, yielding bank voltage of **12.6v - 9v**.((https://batteryuniversity.com/learn/article/confusion_with_voltages))  This lower voltage may trip [[electrical:12v:lvd|Low Voltage Disconnect]] on [[electrical:inverter|inverters]] or [[food:refrigeration|refrigerators]]. 
    
  
 There are hobbyists who build 4S packs and undercharge the cells to only 3.7v.  This gives an operating range of 14.8v - 12v, a much better fit for nominal 12v systems. The downside is this configuration only uses 58% of the cells' capacity and will require more cells to achieve the same amount of Ah.   There are hobbyists who build 4S packs and undercharge the cells to only 3.7v.  This gives an operating range of 14.8v - 12v, a much better fit for nominal 12v systems. The downside is this configuration only uses 58% of the cells' capacity and will require more cells to achieve the same amount of Ah.  
 +
 +**7S builds** make a decent **24v bank**.  They are 29.4v fully charged and 21v discharged, compared to lead acid's 29.6v max voltage and 24.2v 50% DoD cutoff.  Discharging 7s li-ion to 24v((3.42v/cell) could help avoid LVD, making 35% of the cells' capacity unusable.   
 +24v banks in general could preclude [[electrical:12v:alternator|alternator charging]], however.
 +
 +
  
 **Pro:** **Pro:**
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 **Con:** **Con:**
   * overcharging or physical damage can cause a runaway condition (ie fire)   * overcharging or physical damage can cause a runaway condition (ie fire)
-  * voltage mismatch -  +  * voltage mismatch - FIXME
  
-Other lithium chemistries like **"Li-ion" and "Li-po"** are rarely used. They are prone to thermal runaway (fire) and 3S packs do not line up well with 12v use.  They are fully charged at 12.6v and and discharged at 9v.((https://batteryuniversity.com/learn/article/confusion_with_voltages)) These lower voltages may trigger low voltage disconnect on devices that expect lead-acid range voltages.  
  
-7S banks make a decent 24v bank.  They are 29.4v fully charged and 80% discharged at 26.11v, compared to lead acid's 29.6v max voltage and 24.2v 50% DoD cutoff.  This could preclude alternator charging, however. 
  
electrical/12v/deep_cycle_battery.txt · Last modified: 2024/04/15 01:00 by frater_secessus

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