Which connectors does Mini UPS Splitter Cable DC 5.5x2.1mm use?

One end is DC barrel plug 5.5x2.1mm, center positive and the other end is 2 x or 4 x DC barrel plug 5.5x2.1mm, center positive.

What lengths does Mini UPS Splitter Cable DC 5.5x2.1mm come in?

Build lengths are 0.3 to 0.5 m.

Mini UPS Splitter Cable DC 5.5x2.1mm, 1-to-2 and 1-to-4 Y Lead

Last updated: 13 September 2026

Overview

A mini ups splitter cable exists because a home or small office internet stack has more than one box on the DC rail and the backup battery has one output. The router, the optical modem and increasingly a camera or a small switch all need to survive the same mains cut, and this lead turns a single 5.5×2.1mm output into two or four feeds. It is a passive fan-out: what the UPS outputs is what every device on it receives, so the two numbers that matter are voltage and total current.

Key Specifications

Connector A	DC barrel plug 5.5×2.1mm, center positive
Connector B	2 x or 4 x DC barrel plug 5.5×2.1mm, center positive
Conductor	20 AWG
Length	0.3 to 0.5 m
Voltage versions	Built to match 5 V, 9 V or 12 V mini UPS output; voltage tag supplied
Alternative size	5.5×2.5mm version available
Polarity	Center positive throughout
Applications	Router, optical modem, camera and small switch on one mini DC UPS
Options	Reversed gender, longer trunk, mixed barrel sizes, voltage tag
Build note	Passive fan-out; no regulation or conversion

Build the current budget before you order

The battery has a finite output, and everything on the fan-out draws from it at once. Work the budget on paper first – it takes five minutes and it is the difference between a backup that lasts an hour and one that lasts ten minutes.

Step	What to record	Where it comes from
1. UPS output	Voltage and the rated output current	The label on the battery – it is the only authority
2. Each load	Steady current, and the startup figure if you can find it	The rating plate on each device
3. Total	Sum of the steady currents	Add them up; compare to the UPS rating
4. Startup surge	The worst single inrush, added to the rest running	A router booting can draw more than it draws running
5. Headroom	The margin left over	Leave some; a battery at its limit sags and devices reset

We do not print assumed figures for your devices on this page. Read the values off the plates, send them if you want a second opinion, and the lead is built to the current stated per your specification.

Voltage has to match first

The point of a small uninterruptible power supply at this scale is ride-through: enough stored energy to carry the stack across a short cut. This splitter does not regulate or convert. Mini UPS units are commonly built in 5 V, 9 V and 12 V versions, and the label on the battery is the only authority. Putting a 12 V device on a 9 V battery gives a device that will not start; putting a 5 V device on a 12 V battery gives a device that will not start again. Check the label on the UPS and the rating plate on each load before ordering, and use the voltage tag supplied on the lead so mixed-voltage kits do not get swapped in a cupboard.

Match the UPS output voltage to every load on the fan-out.
Add up the current of all loads and stay inside the UPS rating.
Watch startup surge – a device that boots while the rest are running is the usual trip.
Where the loads are mixed voltages, the answer is separate batteries, not one splitter.

5.5×2.1mm or 5.5×2.5mm

Both sizes appear on mini UPS hardware and the difference is the socket pin, not the outer shell. A 5.5×2.1mm plug will enter a 5.5×2.5mm socket and feel loose, which shows up as an intermittent drop rather than a clean failure – and an intermittent drop on a router is a hard thing to diagnose remotely. Units shipped with 5.5×2.5mm leads exist in reasonable numbers, which is why the 2.5 mm version is offered alongside the 2.1 mm one. Measure the pin if there is any doubt.

Why the lead is short and the gauge is 20 AWG

The build quoted for these leads is 20 AWG at 0.3 to 0.5 m overall, which suits a shelf or a desk where the battery sits next to the equipment. Short is deliberate. At 5 V especially, extra length costs voltage that the loads need: the drop is proportional to length and to current, and on a 5 V rail there is very little to lose before a device resets. Keep the battery as close to the devices as the layout allows and order the shortest lead that reaches. Where the battery has to sit further away, tell us the distance and the total current and we will size the conductor to it rather than shipping something that browns out under load.

Termination direction

Note the direction before ordering. Many mini UPS units present their output on a male barrel, so the splitter is built male to two or four male plugs, matching the inputs on the router, modem and camera. If your unit presents a female output, tell us and we build the reversed version rather than shipping a lead that cannot be connected. Mixed barrel sizes on the outputs are possible too, where one device in the stack takes 2.5 mm and the rest take 2.1 mm.

Typical applications for this mini ups splitter cable

Router and optical modem sharing one battery through a mains cut
Adding a camera or a small switch to an existing mini DC UPS
Small office racks where one battery covers the whole network edge
Point-of-sale and kiosk installations with a compact backup
Remote sites powered through a vehicle DC feed and buffered by a battery
Setups that also need a longer drop to the dish, via a Starlink Mini DC extension cable

How to specify your build

UPS output voltage – 5 V, 9 V or 12 V.
Number of outputs – 2 or 4.
Gender at each end – check which way your unit presents its output.
Barrel size – 5.5×2.1mm or 5.5×2.5mm, measured at the socket.
Total current the trunk has to carry, stated per your specification.
Length – shortest that reaches.
Voltage tag, so mixed kits stay sorted.

Workmanship and testing

IPC/WHMA-A-620 Class 3 sets the workmanship bar here, backed by an ISO 9001 quality system and a 32 to 12 AWG termination range. Nothing is packed until continuity and pinout have been verified. Where an ingress rating is specified, seal checking on the batch is available.

Custom builds and ordering

Prototyping starts at 5 pcs with 3 working days to shipment; production is quoted from 500 pcs at 14 working days after approval. Where the body needs a tool we do not stock, allow about 10 working days. OEM and ODM shipments carry your part number and labeling, and material certificates plus first-article reports are available.

Related DC assemblies

Full range: DC plug power cable assemblies.

Frequently Asked Questions

Can I mix a 9 V device and a 12 V device on one splitter?

No. The splitter is passive, so everything on it receives the same voltage. Mixed voltages need separate batteries or a converter.

How do I know if my UPS output is male or female?

Look at the socket on the battery. If it presents a pin, the splitter input needs to be female, and the other way round. Send a photo if you are unsure.

Why does my router reset when the mains cuts?

Usually either a voltage mismatch, a startup surge above what the battery can deliver, or too much drop in too long a lead at 5 V. Check all three in that order.