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opinion:frater_secessus:endamps [2021/05/05 11:31]
frater_secessus created
opinion:frater_secessus:endamps [2021/05/05 11:53]
frater_secessus [How do I know when my lead battery is fully charged?]
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 Note:  Flooded, AGM and gel are all types of lead-chemistry battery. Note:  Flooded, AGM and gel are all types of lead-chemistry battery.
  
-====== How do I know when my lead battery fully charged? ======+====== How do I know when my lead battery is fully charged? ======
  
 Lead batteries are [[electrical:batterycide|killed]] by 'dwellers [[electrical:12v:psoc|undercharging]] them:  not fully, and/or not often enough.  To reach the expected cycle lifetime((at a given [[electrical:depth_of_discharge|depth of discharge]])) a lead battery must be charged: Lead batteries are [[electrical:batterycide|killed]] by 'dwellers [[electrical:12v:psoc|undercharging]] them:  not fully, and/or not often enough.  To reach the expected cycle lifetime((at a given [[electrical:depth_of_discharge|depth of discharge]])) a lead battery must be charged:
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 So how do we know when the battery is fully charged?  When I have topped it off for 15 minutes from the alternator?  (bzzzt) When the controller drops to Float? (bzzzt) When it is above 12.7v?  (bzzzt) So how do we know when the battery is fully charged?  When I have topped it off for 15 minutes from the alternator?  (bzzzt) When the controller drops to Float? (bzzzt) When it is above 12.7v?  (bzzzt)
  
-**A lead battery is charged when acceptance at Absorption voltage has dropped to a specified value.**+**A lead battery is charged when acceptance at Absorption voltage has dropped to a small fraction of its rated capacity.**
  
-===== What does that mean? =====+===== WTF does that even mean? =====
  
 Let's break it down. Let's break it down.
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 > A lead battery is charged when acceptance > A lead battery is charged when acceptance
  
-//Acceptance// is the amount of **charge current** the battery bank is accepting. Since there may be loads this may not be the same amount the charger is putting out.  +//Acceptance// is the amount of **charge current** the battery bank is accepting. Since there may be loads this may not be the same amount the charger(([[electrical:solar:charge_controller|solar charge controller]], [[electrical:12v:b2b|dc-dc]], [[electrical:converter|converter]], whatever)) is putting out.  
  
-Example: the charger(([[electrical:solar:charge_controller|solar charge controller]], [[electrical:12v:b2b|dc-dc]], [[electrical:converter|converter]], whatever)) is putting out 10A.  Loads (laptop, lights) are consuming 6A.  The bank's acceptance is 4A. (10A - 6A - 4A).+Example: the charger is putting out 10A.  Loads (laptop, lights) are consuming 6A.  The bank's acceptance is 4A. (10A - 6A - 4A).  It //must// be;  chargers only put out what the system will take.((or else voltage would keep rising)) 
  
 The presence of loads can make assessing acceptance tricky, which is why we watch current going in/out of the bank with a [[electrical:12v:battery_monitor|battery monitor]] (shunt or clip-on meter). The presence of loads can make assessing acceptance tricky, which is why we watch current going in/out of the bank with a [[electrical:12v:battery_monitor|battery monitor]] (shunt or clip-on meter).
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 ^ fraction       ^ percentage      | **decimal**      | **actual values for 100Ah bank**  | ^ fraction       ^ percentage      | **decimal**      | **actual values for 100Ah bank**  |
 | C/200 - C/100  | 0.5% - 1% of C  | 0.005C - 0.010C  | 0.5A - 1A                         | | C/200 - C/100  | 0.5% - 1% of C  | 0.005C - 0.010C  | 0.5A - 1A                         |
 +
  
 ===== putting it all together ===== ===== putting it all together =====
  
-Battery X (100Ah) is fully charged when the battery is only accepting 0.5A to 1A at 14.5v.  +Battery X (100Ah) is fully charged when the battery is only accepting 0.5A to 1A at 14.5v.((Totally made-up example.  Follow the charging specs your battery manufacturer publishes.)) 
 + 
 + 
 + 
 + 
 +===== how long does it take? ===== 
 + 
 +As your dad might say, "it takes as long as it takes" The battery bank is driving the bus here and we are along for the ride.  
 + 
 +A deep-cyle battery discharged to 50% typically takes [[opinion:frater_secessus:charging_faster|several hours at Vabs]] to fully recharge.
  
  
opinion/frater_secessus/endamps.txt · Last modified: 2021/05/05 11:54 by frater_secessus