Batteries Flashcards
What materials make up the construction of a Lead Acid Battery?
-Plates
• positive plates ( PbO² )
• negative plates ( Pb )
-Separators
-Cell elements
-Electrolytes
-Cells
-Battery case
What is a deep cycle battery
-Fewer but heavier plates than an automotive battery
- Designed for lower current discharge over a longer time.
- Battery life can be greatly extended if the depth of each discharge cycle is kept above 50%.
Marine Battery
- Has some characteristics of automotive and deep cycle batteries.
- Not a suitable replacement for deep cycle batteries on an RV
- Not a suitable replacement for starting batteries in cold climates.
Battery install
• Must be securely attached
• Compartments must be vapor tight to the interior and vented to the exterior
• Circuit protection must not be more than 5 feet from the battery and must be within 18.5 inches from where the cable enters the RV.
Battery storage
• Store fully charge
• Disconnect any loads.
• Store in a cool, dry area.
• Recharge periodically… at least every 1 to 2 months.
Battery maintenance
•Always disconnect the ground cable first and reconnect last?
• Inspect cells for correct electrolyte level.
• Fill to the bottom of the inspection hole with distilled water.
• Never attempt to charge a frozen battery.
• Never charge a battery that has the electrolyte level below the top of the plates
Battery installation
• Never mix batteries of different voltage amp hour rating or age
• Batteries connected in parallel, will increase amperage and voltage will not change.
• Batteries connected in series will increase the voltage, and amperage will not change.
Battery principles
•EMF ( Voltage ) is produced from an acid acting on 2 different materials.
• In the case of lead acid batteries, the electrolyte is acid-based, and the cell plates are 2 different types of lead materials.
• When discharging, So4 ( sulfate ) moves to both plates from PbSo4 ( lead sulfate ), the O² ( oxygen), and H² ( hydrogen) combine to form H²O ( Water )
• Fully charged battery
- Positive plates: PbO2 ( lead peroxide)
- Negative plates: Pb ( sponge lead )
- Electrolyte: 36% H2SO4 ( sulfuric acid)
64% H²O ( water )
• Cell plates are connected in parallel. Positive plates together and negative plates together.
Automotive battery
• Sometimes called the “starting battery” or in the RV industry, the “chassis” battery.
• Has more and thinner plates than a deep cycle battery.
• Design to supply high current over a short period
Battery testing
• Voltage should be approximately 2.13 Volts / cell
• 12 volt battery: 6 cells times 2.13 Volts =12.78 Volts
• 12.0 Volts Considered a dead battery
• 6 volt battery: three cells x 2.13 volts = 6.39 volts
Limitations of lithium-ion batteries.
• They have a tendency to overheat. And can be damaged at high voltages.
• Most lithium-ion electrolytes are highly flammable, so damaged batteries can experience thermal runaway and combustion.
• Because of the risks associated with lithium-ion batteries, a number of shipping companies refused to perform bulk shipments of batteries by plane.
• Lithium-ion batteries require safety mechanismsk to limit voltage and internal pressures, which can increase weight and limit performance in some cases.
• Lithium-ion batteries are also subject to aging. Meaning that they can lose capacity and frequently fail after a number of years.
• Degradation, cost, and safety make Lithium-ion batteries a poor fit for grid scale energy storage.
• Despite the high energy density of lithium-ion compared to other kinds of batteries.
• They are still around a 100 times less energy dense than gasoline, which contains 12,700 Wh/kg by mass or 8760 Wh/L by volume.
Advantages of lithium-ion batteries.
• High energy density.
• Lightweight
• Long lifespans
• Good long term performance
• Temperature tolerant
• Low self discharge
• Fast charge times
• Customizable technology
