How To Replace & Upgrade Your APC Smart UPS Battery

We’re not going to be too harsh on APC for its high battery prices, as replacement units for its SMT/SUA 1400 and 1500 “Smart-UPS” systems include a bunch of hardware that you just don’t get with most other brands of sealed lead-acid batteries. Yet we’re just going to say upfront that if you already have a dead UPS battery, you already have the additional parts you need to convert a basic unit of the same dimensions. And not sticking to the original equipment supplier also opens buyers up to the possibility of upgrades, which is what we did here.

This is the older of two units we decided to revive and upgrade to deal with our power needs in light of the more-frequent severe whether experienced locally: The other, shown here, started showing battery errors after 10 years, though its runtime had been noticeably decreasing for nearly two. Eight years seems reasonable for trouble-free lead-acid battery operation.

Replacement starts with pulling off the snap-on face panel. APC provides a finger grip on each side to ease the process, though using it that way requires tough fingers.

A structural panel behind the plastic face keeps the battery pack from shifting around. Two screws at the top and hooks at the bottom keep it secure.

The hooks at the bottom of the front panel allow it to tilt forward and act as a tray upon which the original battery can be slid out of the backup unit’s main casing.

APC normally tapes a pull tab to the bottom of its battery to help it slide out, but the one on this unit tore off. We grabbed it by hooking a finger on an edge of its central cover.

Sliding the battery pack out of the way reveals a two-pin slip connector. These connectors are unlatched and slip apart with modest force.

The APC RBC7 battery pack is revealed in all its glory. A crease down the side sheds some light upon the secret its additional components conceal…

The ~$160 RBC7 battery pack consists of two ~$40 SP12-18 (12-volt, 18 amp-hour) batteries, a fused bridge, a power connector, and two terminal covers. The batteries are stuck together using double-sided adhesive foam sheet, and the terminal covers are attached with the same adhesive foam. Running a knife under each side of the terminal covers will cut the foam, though one should avoid the center so as not to cut its plastic rib (or short the terminals).

Anyone careless enough to have discarded their original battery without removing the power connector or fused bridge can find a set for around $20 on eBay.