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electrical:12v:drop-in_lifepo4 [2024/04/12 23:00]
frater_secessus [Charging cut-off] 		electrical:12v:drop-in_lifepo4 [2024/06/19 19:36] (current)
frater_secessus [chargers]
Line 85: Line 85:
 Lithium can famously accept huge amounts of current;  this does not mean it is //good// for it to do so. Lithium can famously accept huge amounts of current;  this does not mean it is //good// for it to do so.
  
-  * Maximum((max for our drop-ins; EV packs can have much greater throughput)) - 1C (100A for 100Ah battery) +  * Absolute maximum((max for our drop-ins; EV packs can have much greater throughput)) - 1C (100A for 100Ah battery) 
-  * Manufacturer recommendation - ≤0.5C (≤50A for 100Ah battery) +  * Manufacturer recommended maximum - ≤0.5C (≤50A for 100Ah battery) 
-  * cycle rating (longest life) - 0.2C (20A for 100Ah battery)+  * recommended / cycle rating (longest life) - 0.2C (20A for 100Ah battery)
  
 Lithium does not have a minimum charging current in the lead-battery sense.  Charge as slow as you like.   Lithium does not have a minimum charging current in the lead-battery sense.  Charge as slow as you like.  
  
 +If you choose to end Absorption based on current, you might start out with [[electrical:12v:battery_capacity|0.05C]] and see where that gets you.  Adjust as needed.  
  
 === voltage === === voltage ===
Line 280: Line 281:
   * to top-balance cells((to the degree this works))   * to top-balance cells((to the degree this works))
  
 +==== myth:  lithium batteries draw the full current until they are almost full ====
 +
 +
 +  * both lead and li chemistry charge acceptance [[electrical:12v:directcharginglfp#current_demands_of_dc-dc_chargers_vs_isolators|will taper]] when charged by a [[electrical:12v:alternator|relay/isolator]], and 
 +  * both will charge ~at [[electrical:12v:b2b|a DC-DC charger]]'s rated output until Absorption voltage is reached
 +
 +If we observed closely we //would// see some differences:  the LFP taper is shaped a bit differently, and that lead Absorption tends to start earlier and last longer.  
  
 ==== myth:  if you don't charge to 14.4v the cells won't balance ==== ==== myth:  if you don't charge to 14.4v the cells won't balance ====
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 Some batteries have BMS with bluetooth or other forms of connectivity.  With these you would be able to see more information, like individual cell balance, statistics, setting and the status of any protections.  Some batteries have BMS with bluetooth or other forms of connectivity.  With these you would be able to see more information, like individual cell balance, statistics, setting and the status of any protections. 
  
 +Having visibility into the state of the BMS/cells might be useful for tech geeks, but often muddies the waters for non-technical customers.  Lack of BT is not a dealbreaker. 
  
  
electrical/12v/drop-in_lifepo4.1712977231.txt.gz · Last modified: 2024/04/12 23:00 by frater_secessus

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