48V Rack Battery Installation Checklist

Most rack battery problems are decided before the module is lifted into place: depth measured from the cabinet’s external footprint, a shelf rating nobody checked, a rectifier left on its old lead-acid profile. The installation then looks correct and fails quietly. This checklist follows the order of a real site, using published LINEX 48V figures.

What Should Be Verified Before the Battery Ships?

Start with the purchase order and the label. The model, BMS firmware and communication protocol must match what the site controller expects. Standard 48V models report over RS485 and RS232; Smart versions use CAN and RS485 and add a DC-DC converter that boosts to 57V. Right voltage with the wrong protocol never appears on the monitoring screen.

Check the documents in the same pass: a UN38.3 test summary and an MSDS for Class 9 transport, plus CE and RoHS documentation for the destination market. Confirm the model on each certificate matches the model on the pallet. Then inspect the delivery. No swelling or impact damage, terminal caps in place, charge within the agreed storage range, since self-discharge is under 5% per 90 days at 25°C.

How Do You Prepare the Rack or Cabinet?

Measure usable depth first, not the external footprint. The outdoor range comes in 600 × 450mm and 600 × 600mm footprints, both external, and both must accommodate 45mm EPS insulation, door hardware and cable bend radius. The 100Ah module is 442 × 420 × 133mm and reaches 482mm with handles and terminals, so specify 600 × 600mm. The 200Ah module is 610mm deep and needs the same footprint checked against internal depth. The full enclosure specification is on the IP65 outdoor telecom cabinet page. For the full model range and sizing tables, see our telecom battery backup guide.

Then budget the rack units: 3U for the 50Ah and 100Ah modules, 4U for the 150Ah and 200Ah, plus 3–6U for the rectifier, DC distribution, breakers and cable management. Confirm the rectifier height before the enclosure is ordered; the U-space arithmetic for a 26U cabinet is worked through in how many 48V 100Ah batteries fit a 26U cabinet.

Weight decides the rest. A 43kg module is a two-person lift; 78kg usually needs equipment or a temporary platform. Mount the heaviest modules lowest, confirm the shelf or bracket rating for the exact layout, and leave the fan path clear. The 6,000-cycle rating is specified at 25°C and 80% depth of discharge, and outdoor cabinets address that with 45mm EPS insulation and a temperature-controlled fan. 600W on the 650mm cabinet, 1500W on 750mm and larger units.

What Does a Correct DC Connection Look Like?

One breaker or fuse per string, rated for DC and sized above the module’s continuous current and below the cable ampacity. The 100Ah module accepts 100A charge and discharge at 25°C, so protection is chosen for that current plus the continuous-load margin your code requires, not for the site’s average load. One breaker on the busbar cannot isolate a faulted module, and the rest of the bank will feed a short circuit through it.

Verify polarity before the breaker closes, use the terminal hardware specified for the module, and torque to the value in the instructions rather than by feel. Keep positive and negative runs together, support the cable so the lugs do not carry its weight, and leave the bend radius clear behind the door. Paralleled strings get the same gauge and the same length to the busbar.

Bond the rack or cabinet to the site earth to local code, label each breaker with its module, and record the serial number against the breaker position. When a string trips two years later, that label turns a site visit into a five-minute diagnosis. The selection logic behind capacity and format is covered in how to choose a 48V telecom battery for a base station.

Which Tests Must Pass at Commissioning?

Measure each module’s open-circuit voltage before closing any breaker; a large difference means the bank will exchange current as soon as the strings are paralleled. Close the breakers one at a time, then set and verify the rectifier: 53.3V equalization, 51.0V float and 40.5V cutoff. A rectifier left on a lead-acid profile will undercharge the bank or trip it.

Then verify telemetry module by module. Every battery should report voltage, current and state of charge over RS485/RS232, or CAN on Smart models, and every alarm should reach the NOC. Open one string breaker and confirm the controller reports that specific module, not a generic bank fault. A bank that reports as a single battery hides the failure the monitoring was installed to catch.

Finish with a load test. Run the site load for an hour and compare delivered energy with the table below, which assumes 80% depth of discharge, the condition behind the 6,000-cycle rating.

If measured runtime falls short of the usable energy column, the cause is usually one string not carrying its share, a rectifier that never reached float, or a load higher than the site survey recorded. Diagnose in that order, then log the settings, serial numbers and breaker positions before sign-off.

Frequently asked questions

Preparing a rack or cabinet site? Send the load, autonomy hours, rack space and destination to our team, and we will confirm the module, the depth clearance and the breaker arrangement against the actual installation. Send your site details and we will reply with a configuration and the matching UN38.3, CE and RoHS documentation.