CCTV Power Supply: How Many Amps Do You Need?
Short answer: add up the current (amps) printed on each camera's label, then add about 25 percent spare, and buy a 12 V DC supply rated at least that high. For example, four cameras rated 0.5 A each need 2 A, plus 25 percent is 2.5 A, so a 12 V 3 A four-channel supply is enough. Our CCTV power supplies cost ₹550 to ₹1,650, from a 12 V 3 A four-channel unit to a 12 V 20 A box; prices are live, include GST, and delivery across India is free.
What does a CCTV power supply do?
Most wired analog HD cameras run on 12 V DC. Instead of plugging a separate adapter in next to every camera, installers use one central supply, usually in the same rack or box as the recorder, and run a power pair to each camera alongside the video cable. One box is neater, easier to put on a UPS, and easier to check when a camera goes dark.
Not every camera needs one. Wi-Fi cameras come with their own small adapter; for example, the CP Plus CP-Z43Q lists DC 5 V, 1 A over USB. IP cameras are usually powered over the network cable by a PoE switch. A central 12 V supply is for wired 12 V cameras.
How to work out how many amps you need
- Read each camera's label or datasheet. Look for the input, written like "12 V DC, 0.5 A" or "12 V, 500 mA". To turn mA into A, divide by 1,000. If only watts are given, divide the watts by 12 to get amps at 12 V.
- Use the maximum figure. Cameras draw more at night when the infrared lights switch on. If the datasheet gives a "max" or "with IR on" figure, use that one.
- Add all the cameras together. Eight cameras at 0.5 A each is 4 A in total.
- Add about 25 percent spare. 4 A plus 25 percent is 5 A. Spare capacity keeps the supply cool, copes with the start-up surge, and leaves room for one more camera later.
- Match the voltage exactly. A 12 V camera needs a 12 V supply. Higher amps on the supply are safe, because a camera only draws what it needs. Higher volts are not safe.
- Count the outputs. A channel-type supply has one fused output per camera. Make sure it has at least as many channels as you have cameras, or plan a distribution board.
Worked examples
| Setup (assumed 12 V, 0.5 A per camera) | Total draw | With 25% spare | Supply that fits |
|---|---|---|---|
| 4 cameras, small shop or home | 2 A | 2.5 A | 12 V 3 A, 4 channels |
| 8 cameras, house with gate and terrace | 4 A | 5 A | 12 V 5 A or more |
| 16 cameras, showroom or school block | 8 A | 10 A | 12 V 10 A |
| 32 cameras, factory or society | 16 A | 20 A | 12 V 20 A, or two smaller supplies |
The 0.5 A figure is only an assumption for the arithmetic. Always replace it with the number on your own cameras.
CCTV power supplies on our store
| Model | What the listing states | Fits (at 0.5 A per camera, with spare) | Price |
|---|---|---|---|
| DP-04 Diplomat 4-channel | 12 V 3 A, supports up to four cameras, surge and fluctuation protection | Up to 4 cameras | ₹550 |
| CP Plus CP-DPS-PD08V2-12D | 8 channel outputs, cable compensation switch, LED per channel, EMI filter, constant current limiting; amp rating on product page | 8 cameras; confirm amps on product page | ₹799 |
| Hikvision 12 V 5 A SMPS | 12 V 5 A power supply for CCTV cameras | Up to 8 cameras | ₹849 |
| DS-2FA120A-DW-IN | 12 V 10 A, built-in protections | Up to 16 cameras | ₹1,175 |
| DS-2FA120K-DW-IN | 12 V 20 A, built-in protections | Up to 32 cameras | ₹1,650 |
The "fits" column uses the same 0.5 A assumption. If your cameras draw more, fewer will fit on each supply.
Why do cameras far from the supply flicker or go dark?
Voltage drops along a long, thin cable. A camera 60 to 90 metres away may receive noticeably less than 12 V, and it can reboot at night when the infrared lights switch on and the current rises. Signs include a picture that rolls, flickers or turns black only after dark.
There are three common fixes:
- Use a supply with cable compensation. The CP Plus CP-DPS-PD08V2-12D lists a cable compensation switch, which raises the output slightly to make up for the drop on long runs.
- Use thicker power cable for the long runs, or a separate pair just for power.
- Put a second supply closer to a far group of cameras, for example at the far end of a godown.
Where should the power supply go, and does it need a UPS?
Mount it indoors, on a dry wall or inside a ventilated rack, close to the recorder. Leave space around it, because power supplies get warm. A CCTV rack keeps the recorder, supply and connections tidy and locked.
If power cuts are common in your area, put both the recorder and the camera supply on a UPS or inverter line. A recorder that keeps running is useless if the cameras lose power at the same moment.
Common mistakes to avoid
- Buying a supply rated exactly at the total draw, with no spare. It runs hot and fails early.
- Using a 12 V supply for a 24 V camera, or the other way round.
- Ignoring the extra current at night when IR lights are on.
- Joining power wires with tape instead of proper DC connectors.
- Powering a PoE IP camera from a 12 V box when a PoE switch would power it over the network cable.
Choosing a supply for door locks and access control instead? That calculation is different; see our access control power supply guide. For camera types and prices, see the CCTV camera buying guide and the CCTV camera price guide. All supplies are in CCTV power supplies.
FAQ
How many cameras can a 12 V 5 A power supply run?
About 8 cameras that draw 0.5 A each, keeping 25 percent spare. If your cameras draw more, especially at night with IR on, fewer will fit.
Can I use a higher amp power supply than my cameras need?
Yes. A camera only draws the current it needs, so a higher amp rating is safe. The voltage must match exactly.
What size power supply do I need for 4 CCTV cameras?
For four cameras at 0.5 A each, a 12 V 3 A supply gives enough spare. Our DP-04 4-channel supply is 12 V 3 A and costs ₹550.
Why does my CCTV camera go off only at night?
At night the infrared lights switch on and the camera draws more current. A supply with too little spare or a long thin cable causes a voltage drop, and the camera restarts.
Do Wi-Fi cameras need a CCTV power supply box?
No. Wi-Fi cameras use their own adapter. For example, the CP Plus CP-Z43Q lists DC 5 V, 1 A over USB.
Do IP cameras need a separate power supply?
Not if they support PoE and you use a PoE switch, which powers them over the network cable.
Prices are NavKar Systems website prices on 27 October 2026, inclusive of GST, and may change.
