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electrical:12v:charging [2020/05/13 12:17]
frater_secessus [charging while using the 12v system]
electrical:12v:charging [2023/09/16 12:22] (current)
frater_secessus [Collected recommendations]
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-[[lifestyle:words_of_wisdom|Words of wisdom]]: “Three stage chargers are easier on your batteries, charge them faster, fuller and help you use less water”((https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/)) – HandyBob+[[lifestyle:words_of_wisdom|Words of wisdom]]
  
-====== charging deep cycle batteries ======+> “Three stage chargers are easier on your batteries, charge them faster, fuller and help you use less water”((https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/)) – HandyBob
  
-Solar charging setups cannot charge at night so the most extreme [[electrical:depth_of_discharge|Depth of Discharge]] typically occurs just before sunrise.  The battery bank must be brought to full charge as soon as possible, both to enhance usability and the health of the batteries. 
  
 +> A [ [[electrical:shore_power|shore power]] ] charger is a stiff source with unlimited energy and time. Your solar is a very soft source of unknown power and only a few hours to get the job done.  - sunking((https://www.solarpaneltalk.com/forum/off-grid-solar/batteries-energy-storage/299490-bulk-absorb-float-equalize-what-does-it-mean#post299490))
  
-A combination of high current charging (shore power? alternator?) combined with solar can be ideal:+> Charging lead acid batteries is not something that you decide to do, or start or stop. The old statement, "I need to idle the engine for a few minutes to "top off" the batteries." is a prescription for turning expensive batteries into paper weights. You want a system that puts the batteries on charge automatically, every time there is even a single ray of sun or that your engine is running -- DiploStrat((https://expeditionportal.com/forum/threads/dual-battery-system-with-ctek-d250-not-charging-battery-over-12-volts.174927/post-2342346)) 
 + 
 + 
 +====== Charging Deep Cycle Batteries ====== 
 + 
 +Solar charging setups cannot charge at night so the most extreme [[electrical:depth_of_discharge|Depth of Discharge]] typically occurs just before sunrise.  The battery bank must be brought to full charge as soon as possible, both to enhance usability and the health of the batteries.  //Full charge// means charging to the [[electrical:solar:charge_controller_setpoints|battery manufacturer's specification]]. It is not [[opinion:frater_secessus:beginner_mistakes#not_enough_charging|a guessing (or hoping) game]]. 
 + 
 + 
 +[[electrical:12v:alt_and_solar|combination]] of high current charging (shore power? alternator?) combined with solar can be ideal:
 > "High amps in the morning when most depleted, and enough solar (hopefully more than enough) to reach and  hold absorption voltage all afternoon = happy long lived batteries" -- Sternwake((http://www.cheaprvliving.com/forums/Thread-charging-from-alternator-effects-on-fuel-milage?pid=263792#pid263792)) > "High amps in the morning when most depleted, and enough solar (hopefully more than enough) to reach and  hold absorption voltage all afternoon = happy long lived batteries" -- Sternwake((http://www.cheaprvliving.com/forums/Thread-charging-from-alternator-effects-on-fuel-milage?pid=263792#pid263792))
  
  
 In general, manufacturers of flooded lead chemistries specify charging at [[electrical:12v:battery_capacity|C/10]] to C/5; this assumes more charging time than solar power allows.((http://www.cheaprvliving.com/forums/showthread.php?tid=23606&pid=288284#pid288284))  AGM are typically charged at C/5 to C/3.  There may not be a practical maximum charging rate for cycled FLA batteries //when charged from solar// As Sternwake put it when describing a C/1.5 (!) charging scenario, "solar is not instant max output."((http://www.cheaprvliving.com/forums/showthread.php?tid=23606&pid=288284#pid288284)) In general, manufacturers of flooded lead chemistries specify charging at [[electrical:12v:battery_capacity|C/10]] to C/5; this assumes more charging time than solar power allows.((http://www.cheaprvliving.com/forums/showthread.php?tid=23606&pid=288284#pid288284))  AGM are typically charged at C/5 to C/3.  There may not be a practical maximum charging rate for cycled FLA batteries //when charged from solar// As Sternwake put it when describing a C/1.5 (!) charging scenario, "solar is not instant max output."((http://www.cheaprvliving.com/forums/showthread.php?tid=23606&pid=288284#pid288284))
-===== three stage charging ===== 
  
-Three stage or "smart" chargers (whether [[electrical:solar:charge_controller|solar charge controllers]] or [[electrical:converter|converters]]) will follow a common pattern.  Battery manufacturers publish different specs for charging and a good charger will let the user configure the charging stages in accordance with that information.+===== Three Stage Charging ===== 
 + 
 +Three stage((some mfg claim 4 or more charging stages, including equalization or proprietary stages.  These three are the essentials.)) or "smart" chargers (whether [[electrical:solar:charge_controller|solar charge controllers]] or [[electrical:converter|converters]]) will follow a common pattern.  Battery manufacturers publish [[electrical:solar:charge_controller_setpoints|specs for charging]] and a good charger will let the user configure the charging stages in accordance with that information.  Less-expensive chargers may have presets for charging different battery types; if you get lucky one of the presets will match your manufacturer's charging recommendations.  
  
 SternWake sums up smart charging:   SternWake sums up smart charging:  
-> "Bulk rate is maximum amps the charging source can supply until the absorption voltage is reached, at that point the amps required to hold the ABSV will taper. The longer the battery is held at ABSV, the more the amps required to hold ABSV will taper. At some point, either time, or the amps required to hold ABSV fall below a threshold and triggers float mode."((http://www.cheaprvliving.com/forums/Thread-Can-a-solar-panel-and-charge-controller-over-charge-a-battery?pid=96956#pid96956))+> "Bulk rate is maximum amps the charging source can supply until the absorption voltage is reached, at that point the amps required to hold the ABSV((Vabs, absorption voltage)) will taper. The longer the battery is held at ABSV, the more the amps required to hold ABSV will taper. At some point, either time, or the amps required to hold ABSV fall below a threshold and triggers float mode."((http://www.cheaprvliving.com/forums/Thread-Can-a-solar-panel-and-charge-controller-over-charge-a-battery?pid=96956#pid96956))
  
 +This graphic((from an unknown Amazon seller)) shows how current and voltage change during the full charge:
  
-The example below will use charging data for Trojan T-105 FLA batteries in serial for a nominal 12v bank at 77F.((http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx))+{{https://images-na.ssl-images-amazon.com/images/G/01/stores/auto/detail-page/B003FTA6F2.03.lg.jpg}}
  
-==== bulk stage ====+Charging won't be as neat as the graphic due to [[electrical:solar:output|varying solar harvest]], varying [[electrical:12v:loads|loads]], etc. In practice "constant current"  means "as much as your solar can produce" [[electrical:generator|Generators]] and [[electrical:converter|shore power charging]] will usually be able to hold a steady level of current.
  
-The bulk stage is a fast and furious rush to get **maximum power returned to the battery bank**.  Since the stage by definition requires all the power the system can generate, this is when controllers typically get the most benefit from MPPT features.+ 
 +The example below will use charging data for a 12v bank of Trojan T-105 FLA batteries at 77F.((http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx)) 
 + 
 +==== Bulk stage ==== 
 + 
 +The bulk stage is a fast and furious rush to get **maximum power((or max //recommended// power)) returned to the battery bank**.  Since the stage by definition requires all the power the system can generate((up to the battery bank's ability to accept it)), this is when [[electrical:solar:charge_controller|controllers]] typically get the most benefit from [[electrical:solar:charge_controller#mppt|MPPT]] features.  
  
 This stage **begins when charging starts** (as when the sun comes up) and **ends when the battery climbs to the acceptance voltage setpoint**, 14.8v in our T-105 example. This stage **begins when charging starts** (as when the sun comes up) and **ends when the battery climbs to the acceptance voltage setpoint**, 14.8v in our T-105 example.
  
-Note:  this is **the only stage it may be useful to charge the bank with a [[electrical:generator|generator]] or [[electrical:12v:alternator|alternator]]**.  After bulk charging is complete the current required begins dropping automatically and usually linearly.  +Note:  this is the stage where it is most useful to charge the bank with a [[electrical:generator|generator]] or [[electrical:12v:alternator|alternator]].  After bulk charging is complete the current required begins dropping automatically and roughly linearly.   
 + 
 +**Mythbuster**:  bulk charging lead banks with higher current does not necessarily [[opinion:frater_secessus:charging_faster|shorten overall charging time]].  Once minimum charge rates are met, fully charging takes roughly the same amount of time.   
 + 
 + 
 +=== charging current === 
 + 
 + 
 +Charging current is stated as a fraction of C; 0.1C is 10A for a 100Ah battery. 
 + 
 +  * Trojan((https://www.trojanbattery.com/resources/battery-maintenance))  
 +    * AGM 0.2C 
 +    * Gel 0.13C 
 +    * Solar Premium and Signature:  0.13C when charging time is unlimited.  "If charging time is limited [like with solar charging], contact Trojan Technical Support for assistance" 
 +  * Renogy 
 +    * LiFePO4 0.2C((https://www.renogy.com/content/files/Manuals/RNG-LFP_Manual_V1.0.pdf)) 
 +    * AGM 0.4C max((https://www.renogy.com/template/files/Specifications/RNG-BATT-AGM12-200.pdf)) unless labeled with 0.3C max 
 +    * GEL 0.3C((https://www.renogy.com/content/RBT100GEL12-G1/GEL100-Datasheet.pdf)) 
 +  * Rolls((https://rollsbattery.com/wp-content/uploads/2018/01/Rolls_Battery_Manual.pdf)) 
 +    * Flooded 0.1C 
 +    * AGM 0.2C (min 0.1C, max 0.3C) 
 +    * GEL 0.2C (min 0.1C, max 0.3C) 
 +  * Lifeline((https://lifelinebatteries.com/wp-content/uploads/2015/12/6-0101F-Lifeline-Technical-Manual-Final-5-06-19.pdf)) 
 +    * AGM up to 5C inrush, 0.2C minimum((https://marinehowto.com/how-fast-can-an-agm-battery-be-charged/)) 
 +  * Odyssey((https://www.odysseybatteries.com/odyssey/docs/us-ody-tm.pdf)) 
 +    * AGM 0.4C minimum, no maximum 
 +  * EastPenn/Deka - 0.3C max((https://www.eastpennmanufacturing.com/wp-content/uploads/Renewable-Energy-Charging-Parameters-1913.pdf)) - 
  
 +==== Absorption stage ====
  
-==== absorption stage ==== 
 The absorption stage, sometimes called //acceptance//((which makes sense)) or //boost//((doesn't make sense!)), is a constant voltage stage during which the battery is brought to full charge.  This stage requires a **great deal of time** but decreasing amounts of current.   The absorption stage, sometimes called //acceptance//((which makes sense)) or //boost//((doesn't make sense!)), is a constant voltage stage during which the battery is brought to full charge.  This stage requires a **great deal of time** but decreasing amounts of current.  
  
-Absorption **begins when the battery reaches the absorption voltage** ([[electrical:12v:electrical notation|Vabs]], 14.8v in our example) and **ends when the battery tapers off current acceptance** to something like [[electrical:12v:battery_capacity|C/100]] ("End Absorb", "endAmps"),  and/or when a period of time has elapsed.  +Absorption **begins when the battery reaches the absorption voltage** ([[electrical:12v:electrical notation|Vabs]], 14.8v in our example) and **ends when the battery tapers off current acceptance**((that the battery is taking from the charging source)) to something like [[electrical:12v:battery_capacity|C/100]] to C/50((1A-2A per 100AH of capacity)) ("tail current", "End Absorb", "endAmps"),  and/or when a period of time has elapsed.  
  
 Example:  if you have a 100Ah battery bank and the manufacturer states that endAmps is C/100, then the battery is fully charged when it is only accepting 1A of current((100Ah/100 = 1A)) **at Vabs**.  An endAmps recommendation of C/200 would be the battery accepting 0.5A of current.((100Ah/200 = 0.5A)) at Vabs.   Example:  if you have a 100Ah battery bank and the manufacturer states that endAmps is C/100, then the battery is fully charged when it is only accepting 1A of current((100Ah/100 = 1A)) **at Vabs**.  An endAmps recommendation of C/200 would be the battery accepting 0.5A of current.((100Ah/200 = 0.5A)) at Vabs.  
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   * charging AGM at C/5 (min rate) resulted in the battery being 77.4% "full" at Vabs and being fully charged in **5hrs, 42 minutes**   * charging AGM at C/5 (min rate) resulted in the battery being 77.4% "full" at Vabs and being fully charged in **5hrs, 42 minutes**
  
 +Solar-only charging at lower current levels may indeed mean 80% of the amps are replaced at the end of Bulk.((An extreme version of this would be older [[electrical:converter|converters]] that charge only at Vfloat -- all the amps could be replaced given enough time.))
  
  
 Some controllers will allow the user to configure the time or ratio of capacity/current (C///n//).  Sternwake says: Some controllers will allow the user to configure the time or ratio of capacity/current (C///n//).  Sternwake says:
-> If your charge controller only holds [absorption] voltage for an hour or two, that is likely not enough time. As long as [there is a load] and you cycle the battery daily, you could set float voltage to 14.8v((for example - secessus)) [to match absorption] without worry. Only when you stop cycling the battery do you need to return float voltage to more regular 13.2v((for example - secessus)) levels. Premature application of float voltage by automatic charging sources is a battery killer.((http://www.cheaprvliving.com/forums/Thread-Solar-or-Battery-Problem?pid=229883#pid229883))+> If your charge controller only holds [absorption] voltage for an hour or two, that is likely not enough time. As long as [there is a load] and you cycle the battery daily, you could [[electrical:12v:eternal_absorption|set float voltage to [absorption voltage]]] without worry. Only when you stop cycling the battery do you need to return float voltage to more regular 13.2v((for example - secessus)) levels. Premature application of float voltage by automatic charging sources is a battery killer.((http://www.cheaprvliving.com/forums/Thread-Solar-or-Battery-Problem?pid=229883#pid229883))
  
 +If Absorption cannot be completed in the max amount of time configurable in the controller (due to damaged/old batteries), **charging at the minimum rate and/or at higher voltage may help [[electrical:severe_battery_use|compensate]]**.
  
  
-==== float stage ====+==== Float stage ====
  
 The float stage is not a charging stage but rather a **maintenance stage**.((insert holy war here))  In it the battery is fed just enough  current to hold the battery at a full charge.  The battery will remain fully charged indefinitely in Float; it does not overcharge. The float stage is not a charging stage but rather a **maintenance stage**.((insert holy war here))  In it the battery is fed just enough  current to hold the battery at a full charge.  The battery will remain fully charged indefinitely in Float; it does not overcharge.
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 Common Vfloat values range between 13.2v for stored batteries to 13.8v for banks that are deep cycled each day. Common Vfloat values range between 13.2v for stored batteries to 13.8v for banks that are deep cycled each day.
  
 +also see [[electrical:12v:eternal absorption|Setting Vfloat to Vabs]]
  
  
-===== charge-and-hold ===== +===== Charge-and-hold ===== 
-Charging can be achieved with a simpler methods like charge-and-hold where the charger has a single setpoint which it holds;  current will drop as the battery accepts less.  + 
 +Charging can be applied((with variable amounts of success)) with a simpler methods like charge-and-hold where the charger has a single setpoint which it holds;  current will drop as the battery accepts less.  
  
  
 Examples include: Examples include:
  
-  * [[electrical:converter|RV converters]], usually preset with a float-type setpoint like 13.4v.    The slow charging associated with this voltage level is offset but the assumption that one is plugged into shore power.+  * [[electrical:converter|RV converters]], usually preset with a float-type setpoint like 13.4v.    The slow charging associated with this voltage level is offset by the assumption that one is plugged into shore power.  
   * power supplies, which will usually have a potentiometer (//pot//) to adjust voltage by +/- 10%.  Shore power assumed.   * power supplies, which will usually have a potentiometer (//pot//) to adjust voltage by +/- 10%.  Shore power assumed.
   * [[electrical:12v:alternator|alternator charging]], where the alternator determines output voltage   * [[electrical:12v:alternator|alternator charging]], where the alternator determines output voltage
  
  
-===== charge-and-stop =====+===== Charge-and-stop =====
  
 [[electrical:solar:charge_controller#shunt_controllers|Shunt]] (on/off) chargers have a charge-and-stop approach where they: [[electrical:solar:charge_controller#shunt_controllers|Shunt]] (on/off) chargers have a charge-and-stop approach where they:
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 Charge-and-stop may be useful when charging battery chemistries like lithium, or when [[electrical:solar:shallow_cycling|shallow-cycling]]. Charge-and-stop may be useful when charging battery chemistries like lithium, or when [[electrical:solar:shallow_cycling|shallow-cycling]].
  
-===== charging AGM batteries =====+===== Charging AGM batteries =====
  
 AGM batteries are kept healthy by: AGM batteries are kept healthy by:
  
   - vigorous Bulk charging((minimum current of [[electrical:12v:battery_capacity|C/5]] up to C/3)) sometimes greater than solar-only charging can provide.((http://www.cheaprvliving.com/forums/Thread-anyone-familiar-with-Worker-AGM-batteries?pid=97068#pid97068))  Consider augmenting with alternator or shore power charging.   - vigorous Bulk charging((minimum current of [[electrical:12v:battery_capacity|C/5]] up to C/3)) sometimes greater than solar-only charging can provide.((http://www.cheaprvliving.com/forums/Thread-anyone-familiar-with-Worker-AGM-batteries?pid=97068#pid97068))  Consider augmenting with alternator or shore power charging.
-  - long Absorption stages +  - long Absorption stages((due to speedier Bulk charging)) 
-  - but lower Absorption voltage (to prevent outgassing) +  - typically lower Absorption voltage (to prevent outgassing)((there are exceptions)
-  - absolutely no Equalizing (which would create heavy outgassing)+  - no Equalizing (which could create heavy outgassing)
  
 Many charge controllers have AGM or GEL modes that handle these setpoints and durations. Many charge controllers have AGM or GEL modes that handle these setpoints and durations.
  
-===== charging other chemistries =====+===== Charging other chemistries =====
  
-See [[electrical:12v:lifepo4_batteries_thread#charging|LiFePO4 (lithium) bare cell charging]] +Lithium packs don't need Absorption or Float stages in the lead-battery sense but those voltage setpoints can be put to good use.    Follow your Li battery mfg's advice on charging
  
-===== equalization =====+  - Absorption voltage - 4S LFP packs are actually 100% [[electrical:depth_of_discharge|state of charge]] at 13.8v, but Li manufacturers typically specify "absorption" charging a bit higher like 14.2v.  This allows for quicker charging and also gives some overvoltage the BMS can use to "top balance" cells.((lower-voltage cells are given a chance to rise to their proper individual voltage of 3.45v)) 
 +  - Float voltage - Li does not like to sit at 100% SoC,((the cells degrade faster at 100%+ SoC)) so a float voltage in the 13s allows them to come down off the peak and rest at a healthier voltage for them while still holding useful capacity.
  
-Sometimes called the fourth stage, "equalizing is an overcharge performed after fully charging deep-cycle flooded/wet batteries. An equalizing charge prevents battery stratification and reduces sulfation which are leading causes of battery failure. Trojan recommends equalizing every 30 days or when batteries have a low specific gravity reading after fully charging... Deep-cycle AGM or gel batteries should NEVER be equalized."((http://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf))+Also see [[electrical:12v:lifepo4_batteries_thread#charging|LiFePO4 (lithium) bare cell charging]] and [[electrical:12v:drop-in_lifepo4#an_approach_to_greater_longevity|thoughts about charging LFP gently]]. 
 + 
 +===== Equalization ===== 
 + 
 +Sometimes called the fourth stage, "equalizing is an overcharge to stir up electrolyte in **stationary** deep-cycle flooded/wet batteries.((the electrolyte may stratify in stationary batteries, resulting in zones of stronger and weaker acid))  Since most vandwellers are mobile and electrolyte gets agitated by the van's movement //EQ may not be required for vandwellers// Information provided below for completeness. 
 + 
 +----- 
 + 
 + 
 + 
 +An equalizing charge prevents battery stratification and reduces sulfation which are leading causes of battery failure. Trojan recommends equalizing every 30 days or when batteries have a low specific gravity reading after fully charging... Deep-cycle AGM or gel batteries should NEVER be equalized."((http://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf))
  
 House banks in rigs that are driven regularly are likely already mixed by jostling, so equalization may be less important. House banks in rigs that are driven regularly are likely already mixed by jostling, so equalization may be less important.
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-===== temperature compensation =====+===== Temperature compensation =====
  
 Accurate charging requires the charger know the temperature of the batteries being charged. In hot temps a full charge will require somewhat lower voltage. Cold temps will require higher voltage((https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/)), enough to trip overvoltage protection in some 12v gear. Accurate charging requires the charger know the temperature of the batteries being charged. In hot temps a full charge will require somewhat lower voltage. Cold temps will require higher voltage((https://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/)), enough to trip overvoltage protection in some 12v gear.
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 This automatic voltage tweaking for temperature may result in your actual battery voltages being observably higher in cold temps and lower in hot temps.  This automatic voltage tweaking for temperature may result in your actual battery voltages being observably higher in cold temps and lower in hot temps. 
  
-===== watering batteries ======+===== voltage sensing and compensation ===== 
 + 
 +Relatively high current on a wire will cause the voltage to read high (while charging) or low (while discharging).  This can affect proper charging, load handling, etc.  Properly sensing and accounting for voltage deviation can make a major difference in the quality of a charging routine.  
 + 
 +See [[electrical:12v:voltage_sensing|this article]] for a list of known chargers with voltage sensing abilities.  
 +===== Watering batteries ====== 
 {{ http://www.trojanbattery.com/wp-content/uploads/2013/07/WaterDia_B.jpg?150}} {{ http://www.trojanbattery.com/wp-content/uploads/2013/07/WaterDia_B.jpg?150}}
-Flooded lead-acid batteries outgas during Absorption, causing a slow loss of water.  They outgas intentionally in Equalization.  To counteract this, the 'dweller must remove the caps and inspect the water level.  If low, distilled water is added.+Flooded lead-acid batteries outgas during Absorption, causing a slow loss of water.((AGM and other VRLA outgas to, but use recombination to remake water from the gases))  They outgas intentionally in Equalization.  To counteract this, the 'dweller must remove the caps and inspect the water level.  If low, distilled water is added.
  
   - check to see if plates are covered with water. If not, add enough to cover the plates   - check to see if plates are covered with water. If not, add enough to cover the plates
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-===== charging while using the 12v system =====+===== Charging while using the 12v system =====
  
 Smart chargers handle charging under load gracefully. As long as there is enough solar power coming in to hold the absorption or float voltage steady those charging stages will not be disturbed. If there is not enough power to hold the prescribed voltage the charger may restart Bulk charging. This behavior may be configurable by the user. Smart chargers handle charging under load gracefully. As long as there is enough solar power coming in to hold the absorption or float voltage steady those charging stages will not be disturbed. If there is not enough power to hold the prescribed voltage the charger may restart Bulk charging. This behavior may be configurable by the user.
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-===== battery voltage while charging =====+===== Battery voltage while charging =====
  
 Battery Voltage = Battery Voc((resting voltage)) + (Charge Current x Ri((internal resistance))) Battery Voltage = Battery Voc((resting voltage)) + (Charge Current x Ri((internal resistance)))
  
 +===== Battery manufacturer charging guidelines =====
 +
 +If your battery does not come with charging instructions then you will have to figure out who actually made the battery, and follow //their// instructions:
 +
 +> Deep cycle battery manufacturers such as East Penn Manufacturing, EnerSys, Exide Technologies, GS Yuasa, and Johnson Controls dominate the global market((https://www.businesswire.com/news/home/20170215005980/en/Top-5-Vendors-in-the-Global-Deep-Cycle-Batteries-Market-from-2017-2021-Technavio))
 +
 +Notice how your brand of battery is not listed?  Batteries may be made to spec for the companies who label and sell them, or just standard batteries rebadged with sellers' branding.  
 +
 +
 +
 +==== Collected recommendations ====
 +
 +The following data has been collected as an overview.  Read the linked documents and make your own decisions rather than relying on the collection. 
 +
 +
 +Note:  the voltages below are what you plug into the controller, and the controller is assumed to have temperature compensation to account for battery temperature.((controllers without external temp sensors are measuring //controller// temp))
 +
 +
 +
 +^ Manufacturer                                                                                                                                                                                                                                                                              ^ Flooded                                                                                                                                                                                                                                       | **AGM**                                                                                                                                                                                  | **Gel**                                                                                                                                                                                                                                                                            | **Lithium**                                                                                                   |
 +| Crown((https://www.crownbattery.com/hubfs/Downloads/Safety.First.Deep-Cycle-Batteries.pdf))                                                                                                                                                                                               | Min: C/10\\ Max: C/5((up to C/4 for CR235, see https://www.altestore.com/static/datafiles/Others/CR-235%20PowerSheet.pdf)) \\ Vabs 14.5v\\ Vfloat 13.5v\\ Veq 15.5v                                                                                                                                                                                                                                                                    |                                                                                                                                                                                                                                                                                    |                                                                                                               |
 +| [[https://www.mastervolt.com/charging-batteries/|Mastervolt]]                                                                                                                                                                                                                                                                                                                                                                                                                                                                           | Min C/6.66((15%)) - C/4\\ Max C/3.33((30%))\\ Vabs 14.25\\ Vfloat 13.8v                                                                                                                  | Min C/6.66((15%)) - C/4\\ Max C/2((much higher than usual))\\ Vabs 14.25v\\ Vfloat 13.8v                                                                                                                                                                                           | Min: n/a\\ Max C/3.33((30%, for "maximum lifespan", somewhat lower than usual))\\ Vabs 14.25v\\ Vfloat 13.5v  |
 +| Rolls / Surrette                                                                                                                                                                                                                                                                          |                                                                                                                                                                                                                                               | [[http://support.rollsbattery.com/en/support/solutions/articles/4345-agm-charging|Min]] C/10\\ Recommended C/5\\ Max C/3.33((30%))\\ Vabs 14.7v\\ Vfloat 13.8v\\ Temp comp **4**mV/cell  | [[http://support.rollsbattery.com/en/support/solutions/articles/4345-agm-charging|Min]] C/10\\ Recommended C/5\\ Max C/3.33\\ [[http://support.rollsbattery.com/en/support/solutions/articles/222287-battery-charging-gel|Vabs]]  14.28v\\ Vfloat 13.28v\\ Temp comp **3**mV/cell  |                                                                                                               |
 +| Trojan                                                                                                                                                                                                                                                                                    | Min C/10\\ [[https://www.trojanbattery.com/tech-support/battery-maintenance/|Max]] C/7.7((13%))\\ [[http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf|Vabs]] 14.82v\\ Vfloat 13.5v\\ Vequal 16.2v\\ Temp comp 5mV/cell  | Min n/a\\ [[https://www.trojanbattery.com/tech-support/battery-maintenance/|Max]] C/5\\ Vabs 14.4v\\ Vfloat 13.5v\\ Vequal n/a                                                           | Min n/a\\ Max C/7.7((13%))\\ Vabs 14.4v\\ Vfloat 13.5v\\ Vequal n/a                                                                                                                                                                                                                |                                                                                                               |
 +| US Battery((https://www.usbattery.com/wp-content/uploads/2014/05/usb-charging-recommendations.pdf))                                                                                                                                                                                       | Charge rate C/10\\ Vabs  14.7v\\ Vfloat 13.0v\\ Vequal 15.3v                                                                                                                                                                                  | Charge rate C/10\\ Vabs 14.7v\\ Vfloat 13.4v\\ Veq (same as Vabs)                                                                                                                        |                                                                                                                                                                                                                                                                                    |                                                                                                               |
 +| Fullriver((http://resources.fullriverbattery.com/fullriver-battery/charging-instructions/batteries.pdf))                                                                                                                                                                                  | n/a                                                                                                                                                                                                                                           | Charge rate C/5\\ Vabs 14.7v\\ Vfloat 13.65v                                                                                                                                                                                                                                                                                                                                                                                                                                |                                                                                                               |
 +| East Penn / Deka((https://www.cruisersforum.com/forums/f14/duracell-gc2-charging-specs-163920.html#post2092450)),((https://www.eastpennmanufacturing.com/wp-content/uploads/Renewable-Energy-Charging-Parameters-1913.pdf))\\ including GC10 (aka Duracell GC2) and GC15 (Duracell EGC2)  | Max C/3.3((.3C))\\ Vabs 14.4V - 14.7V\\ Vfloat 13.8V - 14.1V\\ Veq 15.0v - 15.3v                                                                                                                                                              |                                                                                                                                                                                          |                                                                                                                                                                                                                                                                                    |                                                                                                               |
 +| Odyssey (by EnerSys)((https://www.continentalbattery.com/assets/Odyssey_Owners_Manual.pdf)),((https://www.odysseybatteries.com/odyssey/docs/us-ody-tm.pdf))                                                                                                                                                                                                                                                                                                                                                                             | Min ~C/3((actually 40% of C/10 rate))\\ Vabs 14.7v\\ Vfloat 13.6v                                                                                                                        |                                                                                                                                                                                                                                                                                    |                                                                                                               |
 +| Energizer GC2 (by Johnson Controls)((https://forum.solar-electric.com/discussion/comment/274935#Comment_274935))                                                                                                                                                                          | Vabs 14.8v\\ Vfloat 13.2v\\ Veq 15.6v                                                                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                    |                                                                                                               |
 +| Interstate GC2((https://www.interstatebatteries.com/support/golf-cart-battery-installation-and-maintenance))                                                                                                                                                                              | Min C/10 \\ Max C/7.7((.13C))\\ Vabs 14.8v\\ Vfloat 13.5v\\ Veq 16.2v                                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                    |                                                                                                               |
 +|                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |                                                                                                                                                                                                                                                                                    |                                                                                                               |
 +
 +====== further reading ======
  
 +  * [[https://web.archive.org/web/20150919125248/https://c34.org/bbs/index.php/topic,8216.0.html|Why going to float is NOT full]]
  
electrical/12v/charging.1589386634.txt.gz · Last modified: 2020/10/11 19:48 (external edit)