Which Replacement Battery Fits an APC Back-UPS 1500? BR, BX, BN and RS Decoded

There is no single "APC Back-UPS 1500" battery. APC has sold at least a dozen different 1500 VA units under the Back-UPS name, and the replacement pack is decided by the full model code printed on the label, not by the 1500 in the name. A BR1500MS2 and a BX1500 both say 1500 VA and take different packs. Find the code, then match it in the table below.

Why "Back-UPS 1500" is not one product

The number in an APC model name is the volt-ampere rating, and APC has reused 1500 VA across four product lines over roughly twenty years: Back-UPS, Back-UPS RS, Back-UPS XS and Back-UPS Pro. Schneider Electric's own classification puts Back-UPS in the standby topology and Back-UPS Pro in the line-interactive topology, which are genuinely different machines inside the same case size [1].

Those lines do not share a battery. Cell count, terminal type, tray geometry and connector differ between them, and in several cases they differ between revisions of the same line. That is why ordering on the phrase "battery for my APC 1500" is the single most common cause of a return.

Find the model code first

Every APC unit carries its exact model code in three places. Check at least two of them before ordering:

• The rear or underside label, printed next to the serial number. This is the authoritative one.
• The front bezel, usually silkscreened under or beside the display.
• The LCD or PowerChute software, under device information, on units that have a display.

Record the full string, including the suffix. BR1500G, BR1500MS, BR1500MS2, BR1500M2-LM and BR1500LCD are five different units, and only the suffix separates them.

Fitment table: every APC 1500 VA model we stock a pack for

Prices are the current Canadian shelf price on this store and change with supply. Each row links to the exact product record, which carries its own specification table.

If your code is not listed, it is almost certainly still in the wider APC Back-UPS replacement batteries range, which covers 115 products, or in the line-specific Back-UPS Pro BR, Back-UPS RS and Back-UPS XS collections.

RBC cartridge codes, and when they mislead

APC also sells its packs under an RBC part number, and the number printed on your existing cartridge is a reliable key when it is legible. The cartridges that most often turn up in 1500 VA Back-UPS units are RBC123 at 104.99, RBC109 at 101.24 and RBC33 at 104.99, with RBC17 appearing in smaller units of the same families.

Check these four things before the pack goes in

Runtime after replacement, and why it may not return to new

A new pack restores the battery, not the rest of the unit. If runtime is still short after a correct replacement, the usual causes are load creep, a charger that has drifted, or ambient temperature. Sealed lead-acid cells are specified around 20 to 25 degrees Celsius, and every degree above that shortens service life [2]. A unit in a closed cabinet will consume packs faster than the same unit on an open shelf.

Runtime is also not linear with load. Adding a second monitor or a network switch cuts backup time by more than the proportion of watts added, because the effective capacity of a lead-acid cell falls as discharge current rises. Compare against the runtime chart on the product record rather than assuming a proportion.

How often, and what to do with the old pack

Schneider Electric's own service-life guidance puts battery strings at 3 to 5 years, ahead of DC capacitors at 5 years and fan assemblies at 5 to 7 years [3]. IEEE 1188 sets the replacement criterion for valve-regulated lead-acid batteries on measured capacity rather than age, which is the better test when you have the means to run it [4].

Sealed lead-acid cells are fully recyclable and must not go in household waste. Canadian customers can drop old packs at any Call2Recycle Canada collection site [5].

When the battery is not the problem

Replace the pack and the alarm persists? On a 1500 VA Back-UPS the remaining candidates are a failed charger stage, an overload, or a genuine fault in the unit. At consumer price points a replacement unit is often cheaper than a repair, and current stock includes the APC BR1500MS2 Back-UPS Pro and the APC BR1500G Back-UPS Pro.

For rack-mount, three-phase or business-critical equipment the calculation is different, and a service call is usually the cheaper answer. GDF Technologies handles UPS battery repair and replacement and APC UPS maintenance across Canada, including units the manufacturer no longer supports. If you are trying to decode an alarm first, their APC fault code guide covers the common patterns.

Sources

1. Schneider Electric, Energy Management Research Center, The Different Types of UPS Systems, White Paper 1, version 10, 2024. Table 4 maps Back-UPS to the standby topology and Back-UPS Pro to line interactive. se.com
2. Schneider Electric, Data Center Science Center, FAQs for Using Lithium-ion Batteries with a UPS, White Paper 231, revision 1, 2018. Specified temperature range for lead-acid cells. se.com
3. Schneider Electric, Guidance on What to Do with an Older UPS, 2025. Table 4, typical service life of replaceable parts. se.com
4. IEEE, IEEE 1188, Recommended Practice for Maintenance, Testing, and Replacement of Valve-Regulated Lead-Acid Batteries for Stationary Applications. standards.ieee.org
5. Call2Recycle Canada, battery collection network. call2recycle.ca
6. APC by Schneider Electric, Back-UPS and Back-UPS Pro product documentation, model codes and replacement cartridge references. apc.com
7. UPSPLUSBATTERY product catalogue, September 2026. Model codes, pack references and Canadian pricing in Table 1. upsplusbattery.ca

Prices quoted are the shelf price at time of writing and are subject to change. No customer installation is described in this article.