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electrical:12v:deep_cycle_battery [2018/12/06 12:11] frater_secessus [Gel cell] |
electrical:12v:deep_cycle_battery [2020/02/20 13:51] frater_secessus [Non-LiFePO4 lithium-ion] |
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- | Common setpoints (check your manufacturer' | + | Common |
* charge [[electrical: | * charge [[electrical: | ||
* Vfloat 13.2v when not deeply cycled; | * Vfloat 13.2v when not deeply cycled; | ||
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This type of VRLA battery gelatinizes the electrolyte to stabilize it. While renowned for their duty cycles, they are rarely used in campers. | This type of VRLA battery gelatinizes the electrolyte to stabilize it. While renowned for their duty cycles, they are rarely used in campers. | ||
- | ==== Carbon foam === | + | ==== Carbon foam AGM === |
Firefly makes the Oasis (AGM) battery with carbon foam. Claimed benefits are: | Firefly makes the Oasis (AGM) battery with carbon foam. Claimed benefits are: | ||
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===== lithium chemistries ===== | ===== lithium chemistries ===== | ||
- | In theory **LifePO4 lithium batteries** should be near perfect for boondocking. | + | Lithium battery banks are lighter and have higher energy density than lead-acid batteries. |
+ | |||
+ | |||
+ | Lithium banks come in three main forms: | ||
+ | * " | ||
+ | * DIY banks, often " | ||
+ | * manufactured complete banks that do not mimic the physical shape of lead batteries | ||
+ | |||
+ | ==== BMS ==== | ||
+ | Because of the very high energy density and sensitivity to temperature and voltage extremes, most Li banks are equipped with a Battery Management System (BMS) which monitors and controls the bank and the cells in it. | ||
+ | |||
+ | Depending on the BMS, features may include: | ||
+ | * protection from overcharging individual cells | ||
+ | * "top balancing" | ||
+ | * protection from over-discharge | ||
+ | * protection from excess current in charging and/or discharging | ||
+ | * prevention of charging when temps are too low((typically freezing or below)) | ||
+ | |||
+ | |||
+ | |||
+ | |||
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+ | |||
+ | ==== LiFePO4 ==== | ||
+ | |||
+ | [[https:// | ||
+ | In theory **LifePO4 | ||
+ | |||
+ | [[https:// | ||
+ | |||
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* can be damaged by heat | * can be damaged by heat | ||
- | For best life (and to decrease the likelihood of cell imbalance) Charge to 13.8v and disconnect voltage at 12.6v.((http:// | + | BMS-equipped LFP banks should be charged according to manufacturer' |
+ | |||
+ | |||
- | The batteries can be charged with either a [[electrical: | ||
- | Technomadia charge to 14.2v, use a minimal " | ||
Further reading: | Further reading: | ||
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* CF [[http:// | * CF [[http:// | ||
- | Other lithium chemistries like **" | ||
- | 7S banks make a decent 24v bank. They are 29.4v fully charged and 80% discharged | + | |
+ | |||
+ | ==== Non-LiFePO4 lithium-ion ==== | ||
+ | |||
+ | Non-LiFeP04 Li-ion [called " | ||
+ | |||
+ | |||
+ | 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. The cells could be fully charged then the output regulated back to more normal 12v voltage ranges. | ||
+ | |||
+ | **7S builds** | ||
+ | 24v banks in general | ||
+ | |||
+ | |||
+ | |||
+ | **Pro:** | ||
+ | * About half the cost of LFP for the same Ah capacity | ||
+ | * widely available | ||
+ | |||
+ | |||
+ | **Con:** | ||
+ | * overcharging or physical damage can cause a runaway condition (ie fire) | ||
+ | * voltage mismatch of 3S to nominal 12v systems | ||
+ | |||