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electrical:12v:charging [2019/07/17 08:17] frater_secessus [charging deep cycle batteries] |
electrical:12v:charging [2020/10/18 12:04] frater_secessus [three stage charging] |
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- | [[lifestyle: | + | [[lifestyle: |
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+ | > “Three stage chargers are easier on your batteries, charge them faster, fuller and help you use less water”((https:// | ||
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+ | > A [ [[electrical: | ||
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+ | > 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." | ||
====== charging deep cycle batteries ====== | ====== charging deep cycle batteries ====== | ||
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===== three stage charging ===== | ===== three stage charging ===== | ||
- | Three stage or " | + | Three stage((some mfg claim 4 or more charging stages, including equalization or proprietary stages. |
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." | + | > "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)) |
+ | 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 | + | {{https:// |
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+ | In reality charging won't be that neat due to [[electrical: | ||
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+ | The example below will use charging data for a 12v bank of Trojan T-105 FLA batteries at 77F.((http:// | ||
==== bulk stage ==== | ==== bulk stage ==== | ||
- | The bulk stage is a fast and furious rush to get **maximum power returned to the battery bank**. | + | The bulk stage is a fast and furious rush to get **maximum power((or max // |
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. | ||
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==== absorption stage ==== | ==== absorption stage ==== | ||
- | The absorption stage, sometimes called // | + | The absorption stage, sometimes called // |
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+ | Absorption **begins when the battery reaches the absorption voltage** ([[electrical: | ||
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+ | Example: | ||
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+ | In practice absorption takes longer when the battery has been discharged deeply and shorter when it has not.((http:// | ||
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+ | **Mythbuster: | ||
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+ | > charge current affects the SOC transition point from bulk to absorption charging - MaineSail((https:// | ||
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+ | MaineSail found that | ||
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+ | * charging AGM at C/2.5 (max rate) resulted in the battery being 63.3% " | ||
+ | * charging AGM at C/5 (min rate) resulted in the battery being 77.4% " | ||
- | Absorption **begins when the battery reaches the absorption voltage** ([[electrical: | ||
Some controllers will allow the user to configure the time or ratio of capacity/ | Some controllers will allow the user to configure the time or ratio of capacity/ | ||
- | > 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 [to match absorption] without worry. Only when you stop cycling the battery do you need to return float voltage to more regular 13.2v levels. Premature application of float voltage by automatic charging sources is a battery killer.((http:// | + | > 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)) |
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+ | 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: | ||
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==== float stage ==== | ==== float stage ==== | ||
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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. | ||
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+ | also see [[electrical: | ||
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===== charging other chemistries ===== | ===== charging other chemistries ===== | ||
- | See [[electrical: | + | See [[electrical: |
===== equalization ===== | ===== equalization ===== | ||
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- ambient temperature as measured by the charger. | - ambient temperature as measured by the charger. | ||
- in the absence of actual measurements the charger will likely use the 77F laboratory standard. | - in the absence of actual measurements the charger will likely use the 77F laboratory standard. | ||
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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. | ||
===== watering batteries ====== | ===== watering batteries ====== | ||
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**Manual chargers** will not be affected by load as they are controlled by the user. | **Manual chargers** will not be affected by load as they are controlled by the user. | ||
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+ | ===== battery voltage while charging ===== | ||
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+ | Battery Voltage = Battery Voc((resting voltage)) + (Charge Current x Ri((internal resistance))) | ||