Overview

BEAM RST050
Robust yet portable mechanical design with aluminum enclosure
Provides backup power to the Beam Terminals
Push button remaining battery capacity LED’s.
Can power external device whilst charging.
Over-current protection.
Designed with an intelligent charging system
Solar-cell compatible

Provides Stand-by power for:
Telephony,
data,
Geo-location alert/monitoring,
Telemetry
Advisory function for special applications

Tech Specs

BEAM RST050
Length: 271mm(10.7in)
Width: 225mm(8.9in)
Height: 45mm(1.8in)
Weight: 5kg(11lb)
Environmental
Operating Temperature 0C to 55C
Storage Temperature -30C to 70C
Operating Humidity 85% non-condensing
Supply Capacity
Supply Voltage Range: 11 to 16v DC, 2.5A
Supply Voltage (Nominal): 12v DC
Supply Current (Maximum): 3A at 12v DC
Supply Current (Average): 0.3A at 12v DC
Protection
Over-current / Short Circuit Protection: > 1A for > 0.3 second, then resumes after 10 seconds.
Over-discharge cell cut-out: Disconnects load when battery < 18v Design Information for Customized Power Systems The information in this section is intended for special purpose applications such as the design of solar powered supplies in remote applications. Power Requirements The RST100 for example draws 140mA in standby and 440mA in-call at 20Vdc input. In terms of power consumption this is 2.8W and 8.8W respectively and an average power requirement of: (2.8W x 22 / 24 = 2.57W) (8.8W x 2 / 24 = 0.733W) = 3.3W. Over the operating voltage range of the batteries, the RST100 input approximates a constant power load. Battery Sizing The batteries used in the RST050 are sized to reach their end-point voltage at the end of a 22 2 discharge cycle for the RSR100, starting from a fully charged state. That is, it is considered that the batteries are discharged after delivering: 3.3W x 24h = 79.2Wh. Charging Efficiency Under a 0.2C constant-current only charging scheme, the batteries used in the RST050 would recover 80% of their lost capacity in 4 hours and 90% in 5 hours. As the batteries reach 90% charge however, the rate at which they take up energy decreases. To make up the final 10% of charge may take as long as 12 hours from start of charge. The use of the three-stage charging scheme employed by the RST050 means that the batteries return close to 100% of charge within 8 hours for a 22 2 discharge whilst supplying a 22 2 load. Thus the effective average battery charge take-up efficiency is: (79.2Wh / 8h = 10W) / 30W = 33%. Solar Cell Sizing The following exercise provides sample calculations for a typical installation where power is provided only by a solar cell. These calculations assume: • Nominal location Rockhampton, Queensland, Australia • Solar cell conversion efficiency 15% • 22 2 operation (see above tables) Using the approximate location of Rockhampton, of Latitude -24 / Longitude 150 yielded a worse case Insolation (kWh/m2/day) of 3.3 in May using the 10 Year Average Minimum. With a conversion efficiency of 15% this is approximately 500Wh/m2/day. Total requirement is 180Wh/day. Dividing the energy requirement by the available energy gives 180Wh/day / 500Wh/m2/day = 0.36m2. (Note that this energy is only available for around 6 hours a day worst case (May). It is advisable to factor in a 50% margin for extra-ordinary weather conditions and cell aging. This yields a solar cell with an area of 0.54 square metres.