NP24-12BFR EnerSys, NP24-12BFR Datasheet - Page 10

• Manufacturer Part Number: NP24-12BFR
• Description: LEAD ACID BATTERY, 12V, 24AH
• Manufacturer: EnerSys

Specifications of NP24-12BFR

• Battery Capacity: 24Ah
• Battery Voltage: 12V
• Battery Technology: Lead Acid
• External Height: 125mm
• External Width: 175mm
• External Depth: 166mm
• Weight: 20lb
• Battery Terminals: Bolt
• Height: 4.92"
• Width: 6.54"
• Brand/series: NP Series
• Capacity: 24000 mAh
• Chemical System: Lead Acid
• Dimensions: 166mmL×175mmW×125mmH
• Primary Type: Rechargeable
• Resistance, Internal: 9.5 Milliohms
• Size: Rectangular
• Temperature, Operating: -15 to +50 °C
• Temperature, Operating, Maximum: +50 °C (Charge), +60 °C (Discharge)
• Temperature, Operating, Minimum: -15 °C (Charge), -20 °C (Discharge)
• Termination: Bolt Fastened
• Voltage, Nominal: 12 V
• Voltage, Rating: 12 V
• Lead Free Status / RoHS Status: na
• Lead Free Status / RoHS Status: na

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Figure 8. Temperature Effects in Relation to Battery Capacity
Figure 9. Overcharge Characteristics of NP7-12 Under
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At higher temperatures, the electrical capacity that can be
taken out of a battery increases. At lower temperatures, the
electrical capacity that can be taken out of a battery
decreases. Figure 8 shows the temperature effects in relation
to battery capacity.
Proper charging is one of the most important factors to
consider when using maintenance free sealed lead-acid
batteries. Battery performance and service life will be directly
effected by the efficiency of the charger selected. The two
charging methods are:
■
■
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This charging method is not often utilized for sealed lead- acid
batteries, but is an effective method for charging a multiple
number of batteries at one time, and/or as an equalizing
charge to correct variances in capacity between batteries in a
group. Caution should be exercised when charging by
constantcurrent. If the charge is continued at the same rate
for an extended period of time after the battery has reached a
fully charged state, severe overcharge may occur, resulting in
damage to the battery. Figure 9 shows the characteristics of
an Genesis NP battery under continuous overcharge
conditions.
Charging
Temperature characteristics
Constant Current Charging
Two Step Constant-Voltage Charging
Constant-Current Charging
Continuous Overcharge
OVERCHARGING CURRENT:0.6A (0.1CA)
AMBIENT TEMPERATURE: 25ºC (77ºF)
CAPACITY TEST:
n=2
1.5A to 10.2V EVERY 100 HOURS
■
Two step constant voltage charging is the recommended
method for charging a sealed lead-acid battery in a short
period of time, and maintaining the battery in a fully charged
standby or float condition,thereafter. Figure 10 illustrates the
characteristics of a two step constant voltage charger.
The characteristics shown in Figure 10 are those of a constant
voltage, constant current charger. In the initial charging
stage, the battery is charged by constant current. The
charging voltage rises, as the charge continues, until it
reaches 2.45 volts per cell, at which point the charging mode
automatically changes to constant voltage charging. During
the constant current charging stage (A-B) the charging current
which has decreased to point B is sensed, and the charging
voltage is switched to the float level of 2.3 volts per cell from
the recovery level of 2.45 volts per cell. The switch to
constant voltage trickle charging occurs after the battery has
recovered approximately 80% of the rated capacity over a
given period of time. This charging method is one of the most
efficient. The recharge time is minimized during the initial
charging stage while the battery is protected from overcharge
by the system switching over to float charge at the switching
point B.
Figure 10. Charging Characteristics of a Two Step Constant-Voltage
Two Step Constant Voltage Charging
Charger
Publication No: US-NP-AM-002 • June 2006