Security Camera Power Supply: Volts, Amps and Plug Size
To choose a security camera power supply, read the input printed on the camera label or in its manual, then pick an adapter that matches the voltage exactly, supplies at least as many amps, has the same plug size and the same polarity, and gives DC output if the camera asks for DC. Get all four right and the camera should behave as it did with the original adapter. Get one wrong and you may see reboots, a black picture at night, or a camera that never turns on at all.
This guide walks through each of those four checks in order, explains what each symptom of a weak or wrong adapter looks like, and tells you when to stop and get help.
Step 1: Find what your camera actually needs
Every wired camera states its power requirement somewhere. Look in this order:
- The label on the camera body. It is often on the underside, on the back of the mounting base, or on a small sticker near the cable. Look for the word "Input" or "DC" followed by a voltage and sometimes a current, for example "DC 12V 1A" or "5V 2A".
- The tag on the camera's power lead. Outdoor cameras with a pigtail cable sometimes print the input on a flag label near the connector.
- The manual or the box. The specification table usually lists the power input and the maximum power draw.
- The original adapter. If you still have it, its "Output" line tells you what the camera was designed to receive.
Write the numbers down before you shop. Do not rely on memory or on what another camera in the house uses: two cameras that look alike can need different supplies, and requirements vary by model.
If the camera has no readable label and no manual, ask the seller for the exact input of your model rather than guessing.
Step 2: Match the voltage exactly
Voltage is the one number that must be the same. A camera marked 12V needs a 12V supply; a camera marked 5V needs a 5V supply.
- Too high a voltage can damage the camera's power circuit, sometimes instantly and sometimes over weeks. Plugging a 12V adapter into a 5V camera can ruin it for good.
- Too low a voltage usually means the camera starts, then struggles: it may boot in a loop, lose Wi-Fi, or fail when the infrared lights come on.
Many wired indoor and outdoor cameras use a 12V DC supply, which is why "cctv power supply 12v" is such a common search, but plenty of small indoor models run on 5V, often through a USB-style lead. Check your label rather than assuming.
Also check the type: almost all camera power adapters output DC (direct current). Some older or specialised cameras need AC. The label will say "DC" or show a straight line with a dashed line below it for DC, and a wavy line for AC. Never swap one for the other.
Step 3: Meet or exceed the amps
Current (amps, shown as "A" or "mA") works differently from voltage. The adapter's rating is the most it can deliver; the camera only draws what it needs. So:
- An adapter rated the same or higher than the camera's requirement is fine. If the camera asks for 1A, a 12V 2A adapter is a safe choice, because the camera will simply take what it needs.
- An adapter rated lower than the camera needs is the problem case. It may work in daylight and then fail under load.
If the camera label only gives watts (W), you can work out the current: divide watts by volts. As a worked example, a camera marked 12V and 6W draws about half an amp, so a 12V adapter rated 1A or more gives comfortable headroom. Use your own camera's numbers, not this example.
Why headroom matters: a camera's draw is not constant. It rises when the infrared LEDs switch on at dusk, when a motorised head pans or tilts, when the camera writes to its memory card and when it heats itself on cold mornings (on models that have a heater). An adapter that barely covers the idle draw can collapse during those peaks. That is why a slightly stronger adapter, at the same voltage, is often the fix for a camera that misbehaves only at certain times.
A note on "cctv adapter 12v 2a": this is a popular rating because it covers many single cameras with room to spare. It is not a universal answer. A 5V camera must not get it, and a camera that needs more than its rating needs a bigger supply.
Step 4: Check the plug size and polarity
Even with the right volts and amps, the plug has to fit and be wired the right way round.
Plug size
Most wired cameras use a round barrel plug. Barrel plugs come in several outer and inner diameters that look almost identical. A plug that is slightly too small may fit loosely and drop out with a light knock; one with the wrong inner pin size may sit in the socket but make poor contact, which shows up as random restarts.
Ways to get it right:
- Read the size from the manual or the original adapter, where it is sometimes printed in millimetres.
- Bring the old adapter or the camera's lead to the shop and test the fit. A good fit pushes in with firm resistance and does not wobble.
- For USB-powered cameras, check whether the camera's socket is micro-USB or USB-C, and use a lead that carries power properly. Some thin "charge-only" cables are poor at delivering steady current.
Polarity
Barrel plugs have a centre pin and an outer sleeve, and either one can be positive. The label shows a small symbol of a dot inside a "C" shape with plus and minus signs on each side. On most cameras the centre is positive, but check the symbol on both the camera and the adapter; they must match. Reversed polarity can stop the camera from starting or damage it.
Step 5: Look at quality and the cable run
The specs on the label are only half of it. Two more things decide whether the adapter delivers what it promises.
Adapter quality. Very cheap adapters sometimes cannot deliver their printed rating, or they get hot and sag as they warm up. Choose a supply from a reputable source with clear markings, and check that it carries the safety marks that are required where you live. If an adapter is too hot to hold comfortably, unplug it.
Cable length and thickness. Low-voltage power loses some voltage along every metre of cable, and thin cable loses more. A camera at the end of a long, thin extension can receive noticeably less than the adapter puts out, which looks exactly like a weak adapter. If you need a long run:
- Keep the adapter as close to the camera as is safe and practical, with the mains part indoors or in a weatherproof box.
- Use a thicker extension cable made for that plug, rather than the thinnest one available.
- Test the camera with the adapter plugged in right next to it. If problems disappear, the cable run is the cause, not the camera.
For placing the adapter and routing cable outdoors, see how to plug in an outdoor security camera safely.
What a weak or wrong adapter looks like
Many "broken camera" reports turn out to be power problems. These symptoms point at the supply:
| Symptom | What it usually means |
|---|---|
| Camera works all day, reboots or goes offline at dusk | Infrared LEDs push the draw above what the adapter can give |
| Picture flashes black and white at night, then cuts out | Same cause: voltage sags when night mode starts |
| Camera clicks repeatedly, lights flicker | It is restarting in a loop because power drops during boot |
| Pan and tilt makes the camera disconnect | The motor's extra draw is browning out the supply |
| Camera dead, adapter light on | Wrong polarity, wrong plug size, poor contact, or a failed camera input |
| Adapter and camera both dead | Faulty adapter, dead socket or tripped breaker |
| Problems only after rain | Water in a connector or a corroded joint, not the adapter rating |
If your camera is failing mainly at night, the CCTV night vision troubleshooting guide covers the IR settings and light sources that can also cause it. If it simply shows offline in the app, work through how to fix a Yoosee camera that shows offline, which checks power first and then the network. For other symptoms, the symptom-by-symptom guide to a security camera not working helps you narrow it down.
Quick test before you buy a replacement
Before spending money, confirm the adapter really is the problem:
- Test the socket with a lamp or a phone charger.
- Check the adapter's light, if it has one. No light usually means no output.
- Swap in a known-good adapter with the same voltage, enough amps, the same plug and polarity, and plug it in close to the camera.
- Watch through one evening. If the camera now stays online at dusk and night vision holds, you have found the cause.
- If nothing changes, reseat the plug firmly, inspect the connector for corrosion, and then look at network or camera faults instead.
The app shows whether the camera is online; menu names may differ slightly by app version. If the camera keeps dropping offline around the same time each evening, that pattern itself points to a power fault.
When to get help
Stop and get help in these situations:
- Any mains wiring. If the camera needs a new outlet, a hard-wired supply or a junction box, switch off the power and use a qualified electrician. Do not open adapters or cut and rejoin mains cables yourself.
- Work at height. For cameras on high walls or under eaves, use a stable ladder with someone holding it, or leave it to an installer.
- Burning smell, melted plastic or a scorched plug. Switch off at the socket, unplug, and do not reuse that adapter or plug in another until the cause is found.
- Unclear labels. If you cannot read the camera's input or the polarity symbol, ask the seller for your model's exact supply rather than guessing.
- The right adapter does not help. If a verified correct supply plugged in close to the camera changes nothing, the fault is likely in the camera or the network, and the seller can advise on repair or replacement.
Install or resell cameras?
If you fit or sell cameras, power faults are some of the easiest calls to prevent:
- Record each camera's input voltage, current, plug size and polarity on the job sheet, so replacements are ordered correctly.
- Keep a few known-good adapters for the camera types you sell, to rule out the supply in minutes on site.
- Plan adapter location and cable thickness before mounting, and test night vision after dark when you can, not just in daylight.
- Label adapters by camera when several cameras share one location, so customers do not swap a 5V and a 12V supply by mistake.
- Explain to customers that a replacement must match the voltage, not just "fit the plug".
If you want to work with Yoosee as a dealer or installer, see the business site.
Frequently asked questions
Can I use a 12V 2A adapter on a camera that needs 12V 1A?
Yes, in most cases. The voltage matches, and the higher current rating only means the adapter can supply more if needed; the camera takes what it requires. Just confirm the plug size and polarity also match.
Can I power a security camera with a phone charger?
Only if the camera is a 5V USB-powered model and the charger can supply at least the current listed on the camera label. Many phone chargers are fine for small indoor cameras, but some cannot hold steady output under load. Never use a USB charger on a camera that needs 12V.
Why does my camera adapter get warm?
Adapters normally get warm while working, especially near their rated limit. If it is too hot to hold, smells of burning or the plastic looks deformed, unplug it and replace it. An adapter of the same voltage with a higher current rating is usually working less hard, so it may run cooler.
Can several cameras share one power supply?
Yes, with a supply made for that purpose, such as a multi-output power box or a single larger adapter with a splitter. The total current must cover all the cameras together with some headroom, and each camera must still get the voltage it needs. For long runs or many cameras, ask an installer to plan the supply and cable.
What happens if I plug in the wrong voltage by mistake?
A higher voltage can damage the camera, sometimes permanently, while a lower one usually just causes reboots or failure to start. Unplug it straight away, connect the correct adapter, and check whether the camera starts normally. If it does not, contact the seller about repair.
Does a power supply affect video quality?
Indirectly, yes. A weak supply can cause the picture to freeze, drop out at night, or show interference lines on some models, and it can make the camera lose its connection. Correct voltage, enough amps and a short, solid cable run remove those causes.