Battery chargers and UPS for telecom sites
Telecom runs on −48 V DC and on sites nobody visits. Modular redundancy and remote telemetry are the whole specification.
What actually goes wrong
A telecom site fails quietly. The rectifier module that died six weeks ago went unnoticed because the others carried the load, and the failure only surfaces when a second module goes and the bank takes over — at which point you have hours, not days. Everything about the design has to assume nobody is there.
What to get right
The decisions on this list are the ones that are expensive to change after the equipment is on site.
N+1 hot-swap modules
A failed rectifier module must not drop the load and must be swappable live, without a site shutdown.
Remote telemetry
SNMP reporting of module status, DC bus voltage, load current and battery state into your NOC. A failure nobody hears about is a failure you find out about too late.
Battery in a shelter
Unconditioned shelters run hot and that is what kills the bank. Temperature-compensated charging is essential, and lithium is often worth the premium.
Wide input window
Semi-urban and rural feeders swing hard. Specify the widest realistic input range rather than the nominal one.
Footprint
Shelter and rooftop space is limited and often rented. SMPS architecture and lithium banks both buy floor area back.
Lightning and surge
Tower sites take strikes. Surge protection and a properly tested earth are part of the power design, not a separate scope.
What we supply into this sector
Industrial Battery Charger
SMPS chargers from 5 A to 30 A and float-cum-boost chargers from 5 A to 200 A, sized to the bank rather than to a catalogue number.
Online UPS
True double-conversion topology from 3 kVA to 200 kVA across three series, with single-phase or three-phase output. Zero transfer time, pure sine output held to ±1%, and up to 96% efficiency. Built and load-tested in Pune.
Servo Voltage Stabilizer
5 kVA to 500 kVA, air or oil cooled, correcting to ±1% output. The right first fix when the MIDC feeder swings all day and the equipment keeps tripping on undervoltage.
Automatic Transfer Switch (ATS)
The supply you are on fails, and the load moves to the one that has not — with nobody at the panel. 10 A to 150 A, single phase and three phase.
Through the life of the machine
Questions we get asked
Anything not covered here, call us — most of it is faster to answer on the phone.
01Why does telecom equipment use −48 V DC?
Historical and practical. Negative earth reduces electrolytic corrosion on buried copper, 48 V sits below most low-voltage safety thresholds, and DC lets the battery float directly across the bus with no inverter in the path — which removes an entire failure mode.
02How do we monitor unmanned telecom sites?
SNMP over your existing backhaul, reporting module status, DC bus voltage, load current, battery state of charge and ambient temperature into the NOC alongside everything else. The threshold that matters most is per-module failure, because in an N+1 configuration that is the one that produces no visible symptom.
03Why is telecom equipment powered from DC rather than AC?
Because the battery is the supply, not a backup to it. In a DC plant a rectifier charges the bank and the load runs from the bus continuously, so there is no transfer and nothing to fail over when the mains goes — the supply simply continues. It is an older arrangement than the AC UPS and still the right one wherever the load is DC and uptime is the whole requirement.
04What is float and boost charging, and why do chargers have both?
Float holds a fully charged bank at a voltage that just offsets self-discharge, which is where a standby bank spends most of its life. Boost is a higher voltage used to recharge a bank quickly after a discharge, or to equalise cells that have drifted apart. Leaving a bank on boost cooks it and leaving a discharged bank on float never fills it, which is why the charger switches automatically rather than being set by hand.
05How is a DC plant sized for a telecom site?
From the load in amps at the bus voltage, the autonomy the site needs, and how quickly the bank must recharge afterwards — that last one is what sizes the rectifier and it is the one most often left out. A site that discharges regularly needs enough charging capacity to be ready before the next outage, not merely enough to run the load.
06What does N+1 mean on a charger, and do I need it?
It means one more module than the load requires, so any single module can fail or be removed without dropping the site. Whether you need it is a question about attendance rather than about the equipment: a site somebody can reach within the hour may not, while a remote or unattended site where a callout takes a day usually does. Modular plant also lets capacity be added later without replacing the cabinet.
We will do the load grading with you
Site survey, load list and a single-line diagram before anything is quoted. That is where the specification is actually decided.