Lithium Battery for Printing Press: Stable Power for Press Rooms
Lithium Battery for Printing Press: Stable Power for Press Rooms
A web press running at speed holds registration within a few hundredths of a millimetre, and the control system that keeps it there is the first thing to suffer when the supply dips. Voltage sag makes servo drives drift, dryers cycle out of temperature, and a job that was seconds from completion goes to waste. A lithium battery manufacturer sizing a press-room bank is not sizing for an outage alone; it is sizing for the ten seconds of sag that costs more than an hour of downtime.
What the Press Actually Needs From Backup
Separate the load into three tiers before you size anything. Control and drive electronics must never see an interruption, so they ride on an online or line-interactive path with a transfer time measured in milliseconds. Dryers, chillers and air compressors are the bulk of the kilowatts but can be dropped without damage. The safe-stop sequence — slowing the web, retracting ink rollers and parking the cylinders — needs a defined burst of energy and is usually the number that sets the bank size.
Where Lithium Beats the Alternatives
Lead-acid needs a conditioned room, periodic watering and an annual replacement budget, and its voltage collapses noticeably under the short, heavy pulses a press draws. LiFePO4 holds its terminal voltage almost flat until it is nearly empty, so the inverter sees a stable DC bus throughout the discharge. It also recharges in a fraction of the time, which matters when two shifts run back to back and the bank has to be ready again inside an hour.
Press Room Backup Options Compared
| Attribute | LiFePO4 | LTO | VRLA Lead-Acid | Flywheel UPS |
|---|---|---|---|---|
| Voltage sag under pulse | Minimal | Minimal | Significant | None (seconds) |
| Recharge time | 1–2 h | <30 min | 8–12 h | n/a |
| Footprint for 40 kWh | Small | Medium | Large | Medium |
| Maintenance | None | None | Watering, testing | Bearing service |
| Cycle life | 3000–6000 | 15000+ | 300–500 | Very high |
Sizing and Placement
Add the control and drive load, then the safe-stop energy, then decide how many minutes of continued running you want before the operators park the press. Most rooms land between 20 and 60 kWh once the dryer load is excluded. Keep the battery out of the ink and solvent storage area: press rooms carry solvent vapour, and a sealed cabinet in a clean adjacent space is both safer and kinder to the electronics.
What to Ask a Supplier
Ask for the inverter transfer time in writing, and for the surge rating that covers the simultaneous start of the drives you intend to protect. Request the cell maker’s name on the bill of materials and a cycle-life figure at the depth of discharge you actually plan to run, not a shallow headline number.
People Also Ask
Do I need to back up the whole press? No, and it is rarely economic. Back up the control and drive tier plus the safe-stop sequence, and let dryers and compressors drop. That usually cuts the required capacity by more than half.
Will a lithium bank handle the inrush when the drives restart? Yes, provided the inverter surge rating is specified against that event. Give the supplier the locked-rotor and simultaneous-start figures rather than the running load.
How long will the bank last in a press room? Expect eight to twelve years in float service with occasional discharge, well beyond the three to five years a VRLA bank gives in the same conditions.
Can it be retrofitted to an existing UPS? Often yes. Many modern UPS cabinets accept a lithium string once the charge profile is updated and the BMS communicates with the charger; older units may need replacing.
Written by Karl at China Battery Technology. Request a quote.
