How to Choose a 12V Power Adaptor: Volts, Amps and Pin Size
Short answer: to choose a 12V power adaptor, match three things to the old adaptor or the device label: the voltage must be the same (12V DC), the current (amps) must be equal or higher than what the device needs, and the pin must fit and have the same polarity. A single 12V 2A adaptor costs ₹449 to ₹599 on our store, and multi-camera 12V supplies from 3A to 20A cost ₹550 to ₹1,650. Prices include GST and delivery across India is free.
What do volts and amps on an adaptor mean?
Every adaptor has a small printed label. Look for the line marked "Output". It will say something like 12V ⎓ 2A. The first number is the voltage, the second is the most current the adaptor can supply.
- Voltage (V) is pushed into the device. It must match. A 12V camera, lock or router needs 12V, not 9V and not 15V. Too low and the device resets or does not start; too high and it can burn out.
- Current (A) is pulled by the device. The adaptor only gives as much as the device asks for. So a 2A adaptor on a device that needs 1A is perfectly safe. The opposite is the problem: a 1A adaptor on a 2A device runs hot, drops voltage and fails early.
- Watts (W) is volts multiplied by amps. A 12V 2A adaptor is 24W; a 12V 5A supply is 60W. Some listings quote watts instead of amps, so this helps you compare.
- AC or DC. Security devices, routers and locks almost always want DC. The symbol is a solid line over a dashed line. Never use an AC-output transformer on a DC device.
How to choose the right 12V adaptor: step by step
- Read the device, not just the old adaptor. The label under the camera, lock or router shows its input, for example "DC 12V 1A". If the old adaptor is lost, this is the number you match.
- Add up the current. If one adaptor will feed more than one device, add their currents. Two devices at 0.5A each need at least 1A.
- Add headroom. Choose an adaptor rated about a quarter higher than the total. Electric locks and motors draw a burst of current when they switch, and cameras with infrared lights draw more at night than in the day.
- Check the pin size. The common round DC barrel plug on CCTV cameras, routers and many access products is 5.5 mm across on the outside, with an inner hole of either 2.1 mm or 2.5 mm. The two look the same but a 2.1 mm pin feels loose in a 2.5 mm socket and a 2.5 mm pin will not go into a 2.1 mm one. Compare with your old plug, or send a photo on WhatsApp.
- Check polarity. Most 12V security devices use centre-positive. The label shows a small symbol with a dot in the middle and plus or minus marks. If the old adaptor and the new one show the same symbol, you are fine.
- Indoor or outdoor. A normal plastic adaptor must stay dry. For a camera on a boundary wall or a lock at an open gate, use a rainproof supply or keep the adaptor inside and run the DC cable out.
Single adaptor or a multi-channel power supply?
For one or two devices, a plug-in adaptor is simplest. For a CCTV system with four or more cameras, a single box supply with separate outputs is neater, safer and easier to service, because all cameras are powered from one point near the DVR. Box supplies also offer features you will not find in a cheap adaptor, such as surge protection, an LED per channel and a cable compensation switch that lifts the voltage slightly for long cable runs.
A rough rule for sizing a box supply: count the cameras, multiply by the current printed on one camera, and add headroom. If each camera's label says 0.5A, four cameras need 2A, so a 3A supply is a sensible pick. Eight such cameras need 4A, so a 5A supply fits. Larger systems with many cameras or infrared floodlights call for 10A or 20A units.
For electric locks, exit buttons and access readers, a plain adaptor is often not enough because the lock needs to be switched by the reader or a remote. That is a different job, covered in our guide to access control power supplies and battery backup.
12V adaptors and power supplies: prices (NavKar Systems, 27 October 2026)
| Model | Output (from listing) | Best for | Price |
|---|---|---|---|
| WPAD-12 Outdoor Waterproof Power Supply | 12V 2A, rainproof | Outdoor camera, gate lock or reader | ₹449 |
| AD-12V Power Adaptor | 12V 2A DC, 220V AC input | Replacement for one camera, router or small device indoors | ₹599 |
| DP-04 Diplomat 4 Ch Power Supply | 12V 3A, 4 channels | Up to four CCTV cameras | ₹550 |
| CP-DPS-PD08V2-12D | 8 channels, cable compensation switch, LED per channel | 8-camera CCTV system | ₹799 |
| Hikvision 12V 5A SMPS | 12V 5A | Small CCTV setup from one supply | ₹849 |
| UPS-12 Mini UPS | In 12–14V DC 2A, out 12V DC 1A, up to 2–5 h backup | Router, Wi-Fi camera or biometric machine through power cuts | ₹950 |
| DS-2FA120A-DW-IN | 12V 10A | Larger CCTV system | ₹1,175 |
| ADP-PS Audio Door Phone Power Supply | Transformer based; junction for handset and outdoor bell | Indian audio door phones | ₹1,250 |
| PK-80 Access Control Power Supply | 12V 3A, AC 110–240V input | EM lock, reader and exit button | ₹1,450 |
| DS-2FA120K-DW-IN | 12V 20A | Big CCTV installations | ₹1,650 |
Not 12V? We also stock the ADTP-5V thin-pin 5V adaptor (₹549) made for the Precision ABAS 100 scanner tab. See the full range in power adaptors and mini UPS, CCTV power supplies and power supplies, remotes and adaptors.
What goes wrong with the wrong adaptor?
- Camera picture rolls or goes black at night: the infrared lights switch on and the adaptor cannot supply the extra current. Use a higher-amp adaptor.
- Electric lock clicks but does not open: the lock needs a burst of current to pull. A weak adaptor drops voltage at that moment. See our checks for a lock that will not open.
- Router keeps restarting: wrong voltage, a loose pin or a tired adaptor. Match the voltage exactly and check the pin fits snugly.
- Adaptor too hot to touch: it is overloaded. Move to a higher rating or split the load across two supplies.
- Nothing works at all: check polarity and that the adaptor gives DC, not AC.
If your router or camera also needs to ride through power cuts, read mini UPS for router and Wi-Fi camera.
FAQ
Can I use a 12V 2A adaptor for a device that needs 12V 1A?
Yes. The device only draws the current it needs, so a higher-amp adaptor at the same voltage is safe. The voltage must match exactly.
Can I use a 12V 1A adaptor for a device rated 12V 2A?
No. The adaptor will overheat and the device may reset or fail to start. Choose an adaptor rated at least 2A, ideally a little more.
What is the pin size of a CCTV camera adaptor?
Most CCTV cameras use a round DC barrel plug 5.5 mm wide, with a 2.1 mm or 2.5 mm inner hole. Compare with your old plug before buying.
How many cameras can a 12V 5A power supply run?
Add the current printed on each camera and keep some headroom. If each camera needs 0.5A, a 5A supply comfortably runs about eight.
Can I use a 9V adaptor on a 12V device?
No. A lower voltage leaves the device underpowered and unstable. Always use the voltage printed on the device.
What is the price of a 12V 2A adaptor?
Our AD-12V 12V 2A adaptor costs ₹599 and the rainproof WPAD-12 12V 2A supply costs ₹449, both including GST with free delivery across India.
Prices are NavKar Systems website prices on 27 October 2026, inclusive of GST, and may change.
