UPS service
On-site UPS battery replacement
We replace UPS batteries on site: complete VRLA strings, external battery cabinets and lithium-ion systems on three-phase and large single-phase UPS. The work is planned around the load, the old batteries are removed for recycling, and the new string is tested before we leave. Same-day dispatch in Montreal, Quebec City, Toronto and Ottawa, 24 to 48 hours elsewhere in Canada.
Key facts
- VRLA battery, 5-year design: Estimated life 5 years; replace at three to four years (Liebert EXM2 manual)
- Inspection interval for VRLA: Every six months (Liebert EXM2 manual)
- Battery at 35 °C instead of 25 °C: Service life reduced by 50% (Liebert EXM2 manual)
When a string needs replacing
VRLA batteries wear out on a schedule that heat shortens. Vertiv's EXM2 manual gives a VRLA battery with a 5-year design life an estimated life of five years and proposes replacing it at three to four years, with an inspection every six months. The same manual warns that if the average battery temperature rises from 25 °C to 35 °C, service life drops by 50%.
The signs we look for on a visit:
- internal resistance or impedance climbing against the baseline;
- block voltages spreading apart on float;
- runtime well short of what the string delivered when new;
- swollen cases, cracked lids, leaks or corroded terminals;
- a string at or past the manufacturer's proposed replacement age.
More detail in how long a three-phase UPS battery lasts.
Crews that do this work every week describe the full scope, from string swaps to battery repair, on a page dedicated to UPS battery replacement and repair. Matching blocks for most brands can be looked up in a catalogue of replacement batteries sorted by UPS model.
How the replacement is done
- Survey. Battery model, number of strings and blocks, cabinet layout, terminal hardware and access are confirmed before ordering.
- Plan the outage window. On systems with one string, the load runs on bypass or a temporary string during the swap. On systems with several strings or modular cabinets, strings are replaced one at a time with the UPS online.
- Replace. Blocks are installed, connections are torqued to the manufacturer's values and checked.
- Test. Float voltages and impedance are recorded as the new baseline; a runtime or load-bank test can follow.
- Remove and recycle. The old batteries leave with us for recycling.
Replace in kind
New blocks should match the original in chemistry, voltage, capacity and dimensions, and come from a manufacturer approved for the cabinet. Mixing old and new blocks in one string shortens the life of the new ones, so strings are replaced as a whole. Moving from VRLA to lithium-ion is a design change, not a battery swap: it needs a battery system qualified by the UPS manufacturer for that model.
Battery rooms and cabinets
Temperature is the main lever on battery life, so we record the room or cabinet temperature on every visit and flag anything above 25 °C. Ventilation, clearances and the condition of racks and cabinets are part of the job. For large strings we also check the DC disconnects and the battery monitoring system if one is installed.
Single cartridges and small UPS
This page covers on-site work on large systems. For a plug-in cartridge in a rack or tower UPS, the batteries can usually be swapped by the owner; we handle them on site when they are part of a larger visit or a fleet. Our guide on new batteries or a new UPS helps decide which makes sense.
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Common questions
How long do UPS batteries last?
A VRLA battery sold as a 5-year design typically needs replacing at three to four years in service, according to Vertiv's EXM2 manual. Heat shortens it further: 35 °C instead of 25 °C cuts service life by half.
Can batteries be replaced without shutting down the load?
Usually. Systems with several strings are re-batteried one string at a time with the UPS online. A single-string system runs on bypass or a temporary string during the swap, which we schedule with you.
Can I replace only the bad blocks?
Only on a young string, and only with matching blocks. Mixing old and new blocks makes the new ones age with the old, so ageing strings are replaced as a whole.
Do you take the old batteries away?
Yes. Old batteries leave with us and are sent for recycling.
Can we switch from VRLA to lithium-ion?
Only with a lithium-ion battery system qualified by the UPS manufacturer for that model. It is a design change with its own controls, not a like-for-like swap.
Do you replace batteries in small rack or tower UPS?
Yes, as part of a site visit or a fleet program. A single plug-in cartridge is often something the owner can change without a visit.
Sources, checked October 4, 2026:
- Vertiv Liebert EXM2 User Manual, 100 kVA to 250 kVA UPS, SL-71070 Rev B (06-23), Table 11.1, p. 164
- Vertiv Liebert EXM2 User Manual, 100 kVA to 250 kVA UPS, SL-71070 Rev B (06-23), Table 7.1, p. 115
- Vertiv Liebert EXM2 User Manual, 100 kVA to 250 kVA UPS, SL-71070 Rev B (06-23), p. 163
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