Q: What do the characters in the model number mean?
A: Example: (SC 18-120 DSO/72-156/3S) (SC) = Safety Charger, (18) = 1800 watts input power, (120) = 120 volts alternating current input voltage, (DSO) = Digital Shut Off, (72-156) = for 72-156 volt nominal voltage battery packs, (3S) = Three Stage.
Back to topQ: What is the Shut Off?
A: The basic charger comes without a shut off. The shut off is optional on the SC18 model and standard on the SC30 model and all Three Stage models. Chargers without a shut off will taper the battery finishing current down to an amp or two at the end of charge and continue until unplugged from the AC power. The shut off will shut off the charger completely when the batteries are fully charged.
Back to topQ: What is the Analog Shut Off?
A: The Analog Shut Off (ASO) is optional on the Two Stage SC18 model. When the battery current reduces to about 70% near end of charge, the non-latching Analog Shut Off timer is started. Approximately 30 to 60 minutes later the charger is completely shut off.
Back to topQ: What is the Digital Shut Off?
A: The Digital Shut Off (DSO) is optional on the Two Stage SC18 model. The Digital Shut Off is standard on all Three Stage (3S) models and the SC30 model. When the battery current decreases to 71.5% (27% on Three Stage models) the latching Digital Shut Off timer is started, as indicated by the ultra-bright LED Power On lamp changing from a steady to a flashing state. After the user set time of ½, 1¼, 2½, or 5 hours has expired, the charger will completely shut off.
Back to topQ: What is the Two Stage charger?
A: The first stage of charging is Constant Current or bulk charge of the batteries. This provides a maximum constant current to charge the batteries as quickly as possible, within the charger rating. The second stage is Constant Voltage or the finishing charge. As the battery voltage rises during charge, the Constant Voltage stage will maintain the battery voltage at the preset level, and the battery current will continue to decrease. Two Stage chargers have two adjustment controls: Current and Voltage.
Back to topQ: What is the Three Stage charger?
A: The three stage charger adds a third stage, which is a Constant Current equalization charge performed directly after the Constant Voltage second stage. The Three Stage charger includes the Digital Shut Off (DSO), which performs the third stage equalization for the user set time of ½, 1¼, 2½, or 5 hours, then complete shut off. Three Stage chargers have three adjustment controls: Current, Voltage, and Shut Off.
Back to topQ: Can a Two Stage charger provide a finishing equalization charge?
A: Yes. After the charger is finished with the constant voltage second stage, the Voltage Control may be manually turned up all the way and the Current Control may be adjusted for the desired equalization current. The charger will provide a constant current allowing the battery voltage to rise above the Constant Voltage second stage.
Back to topQ: Can a Three Stage charger be used without the Third Stage equalization charge?
A: Yes. The Shut Off Control may manually be turned all the way down. The charger will now operate as a Two Stage charger.
Back to topQ: What is the Current Control for?
A: The Current Control adjusts the maximum first stage current. The Current Control is usually set all the way up unless using an AC service of lesser rating than the charger used. In this case, the Current Control may be turned down to reduce the maximum current drawn from the AC service.
Back to topQ: What is the Voltage Control for?
A: The Voltage Control adjusts the second stage desired battery finishing voltage. The Voltage Control can be set for 72-156 nominal pack voltage.
Back to topQ: What is the Shut Off Control for?
A: The Shut Off Control is used on Three Stage (3S) chargers only and adjusts the third stage constant equalization current.
Back to topQ: Is shipping included in the charger price?
A: Shipping is extra and is usually $20-$35, depending on the charger or transformer weight and the shipping distance.
Back to topQ: How are orders shipped?
A: UPS, with full insurance and tracking. Orders to Hawaii are sent USPS Priority Mail with insurance and delivery confirmation.
Back to topQ: May I order chargers direct from the Russco Factory?
A: Yes.
Back to topQ: How do I pay for a charger?
A: Your personal check mailed to the Merlin address in the contact information is acceptable.
Back to topQ: Do you accept charge cards or PayPal for payment?
A: Not at this time.
Back to topQ: Do you have chargers in stock at all times?
A: We try to, but if not, will build one.
Back to topQ: If I have questions about a charger, who do I contact?
A: Phone or email the Russco Factory listed in the contact information.
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