Beginner metal detectorists likely have many questions when they first get into the hobby, and one potential line of inquiry is how metal detectors are powered. Do all metal detectors need batteries, or do they get their power from an alternative source?
Portable metal detectors are electronic devices that require batteries. Most metal detector manufacturers recommend using alkaline batteries in their metal detectors for better battery life.
In this article, I’ll answer all your questions about metal detecting and battery usage, including how metal detectors are powered, how to change the battery, and how to increase battery life.
How Are Metal Detectors Powered?
Metal detectors are electronic devices that rely on batteries for their power. Most metal detectors need AA batteries, D batteries, or 9-volt batteries. Many metal detector manufacturers recommend using alkaline batteries for their products.
Portable metal detectors are almost always used outside, far away from any power outlets, so they get their power through batteries. Batteries contain cells that have chemical reactions, which create a circuit. Electrons then flow through the circuit, generating electricity that the device can use for its power.
Most metal detectors use AA batteries, D batteries, or 9-volts. Let’s take a look at each of these battery types:
- AA batteries. AA batteries are some of the most popular batteries in use today. They are a classic size and shape; you probably already have some lying around. You can get rechargeable, lithium, or alkaline AA batteries.
- D batteries. D batteries are dry cell batteries, which are more barrel-like in shape than AA or AAA batteries. You can get rechargeable and non-rechargeable D batteries. In addition to metal detectors, D batteries are often used in electric motors, electronic toys, and megaphones.
- 9-Volt batteries. 9-volt batteries are also common for metal detector use. These batteries have a rectangular shape and are available in alkaline, carbon-zinc, and lithium chemistries.
These are the common sizes and shapes of batteries that metal detectors use, but we also need to discuss the types of batteries available.
- Lithium-ion. A lithium-ion battery is a rechargeable battery that uses lithium ions and a liquid electrolyte to move from the negative electrode to the positive side. They are becoming more popular for portable electronic devices, including metal detectors.
- Lithium-polymer. A lithium-polymer battery is similar to a lithium-ion battery, but it uses a high-conductivity gel polymer instead of a liquid electrolyte.
- Lithium. Lithium batteries feature an anode and a cathode, and electrolytes carry positively charged lithium ions from the sides to create free electrons. This creates an electrical current that flows to the metal detector and powers it.
- Alkaline. Alkaline batteries use manganese dioxide and zinc to generate energy. They typically have a longer shelf life than other batteries.
Most metal detector manufacturers suggest using alkaline batteries with their metal detectors. Let’s discuss why.
Alkaline batteries provide better long-term power than lithium batteries, which makes them a better choice for metal detecting. Alkaline batteries usually have 1.5 volts in every AA battery, which is more than the standard 1.2 volts in a standard rechargeable battery. The extra voltage in an alkaline battery usually results in a longer usage time before the batteries die and need to be replaced.
Another benefit of alkaline batteries is that they have a longer shelf life than other batteries. They have a low self-discharge rate of just 0.3% per month, so you can keep some in your house as a backup for a long time without losing all their power. They’ll keep their power for even longer if you store them in a dry place with a moderate temperature. Some people put their batteries in the freezer to extend their shelf life, but this isn’t necessary.
One drawback of alkaline batteries you need to be aware of is that they don’t work well in cold weather. If you are in a cold climate, you’ll likely need to replace your alkaline batteries more frequently because of their poor performance.
What Kind of Battery Does My Metal Detector Need?
The type of battery a metal detector needs varies based on your brand and type of detector. The following table outlines the most popular portable metal detectors and the type of batteries they use:
| Metal Detector | Battery Type |
| Bounty Hunter Legacy 3500 | Alkaline 9-Volt |
| Bounty Hunter Platinum Pro | Alkaline 9-Volt |
| Detech EDS Gold Catcher | Alkaline AA |
| Fisher Labs F22 | Alkaline AA |
| Fisher Gold Bug Pro | Alkaline 9-Volt |
| Garrett Ace 250 | Alkaline AA |
| Garrett ATX Waterproof Deepseeker | Alkaline AA |
| Garrett Goldmaster | Alkaline AA |
| Minelab Vanquish 440 | Alkaline AA |
| Minelab Equinox 800 | Lithium Ion |
| Minelab CTX 3030 | Lithium Ion |
| Nokta Mini Hoard Waterproof Kids Metal Detector | Alkaline AA |
| Nokta Makro Gold Finder | Lithium Polymer |
| SUNPOW OT-MD02 Metal Detector | Alkaline AA |
| Teknetics Omega 8500 | Alkaline 9-Volt |
| XP ORX Wireless Metal Detector | Lithium |
If you can’t find your metal detector model in this table, I recommend looking at your user’s manual or calling the company to find out what kind of battery you need.
Some models and brands require specific batteries made for their machines. If that’s the case with the metal detector you have, you may need to purchase replacement batteries directly from the company.
How To Change Metal Detector Batteries
The process of changing metal detector batteries varies based on the make and model of your metal detector, but in general, you’ll follow these steps:
- Remove the compartment cover. This cover is on top of the control housing.
- Pull out the old batteries.
- Place the new batteries in the same position as the old batteries, ensuring that the battery connectors are facing up.
- Replace the battery compartment cover.
Most metal detectors require more than one battery. If this is the case with yours, you should never mix battery types. For example, if one battery is alkaline, the rest should be alkaline too. I also don’t recommend mixing old and new batteries. Even if one battery isn’t yet completely dead, it is better to replace all the batteries at once.
How To Increase Battery Life
The battery life inside your metal detectors varies greatly depending on your metal detector type, how often and consistently you’re using it, and how your metal detector is calibrated. For more information on calibration, check out my article on how often to calibrate metal detectors: How Often Should Metal Detectors be Calibrated?
Generally, batteries last for about 20 hours in a metal detector. However, I always recommend having an extra pair of batteries on you while you’re out in the field so you don’t have to give up and go home should the batteries die.
There isn’t a lot you can do to increase battery life, but here are a few tips and tricks you can implement to reduce the frequency with which you need to replace your metal detector batteries:
- Use headphones. I recommend using headphones while metal detecting regardless because they help block out excess noise and make it easier to hear your metal detector signals. Still, it also takes less energy to send a signal through headphones than to send a signal out loud through the speaker, especially if the volume is turned up so you can hear it.
- Use the lowest effective sensitivity setting. There’s usually no reason to have your metal detector’s sensitivity turned up. Having the sensitivity set on a high level drains the battery more quickly, and you’ll waste more time digging up trash. I recommend setting the sensitivity to the lowest level possible for the kind of metal you’re looking for.
- Don’t search in areas with lots of trash. Every time your machine has to give a signal, it uses energy from the battery to do so. Therefore, if you’re detecting in an area with lots of trash, the metal detector will give off lots of unnecessary signals and use up the battery more quickly for undesirable objects.
- Don’t mix old batteries with new batteries. Some people think mixing old and new batteries helps extend the life of the older battery, but this isn’t true. It is better to always change both batteries at the same time.
- Don’t metal detect near other metal detectors. Metal detectors interfere with each other, which can drain the battery. For more information, check out my article about metal detectors interfering with each other: Do Metal Detectors Interfere With Each Other?
By implementing these tips, you can reduce the batteries you need to buy and how often you need to replace the batteries in your detector.
If you need metal detecting headphones, I highly recommend the Garrett ClearSound Easy Stow Headphones from Amazon.com because they reduce background noise and help you hear the tones from your metal detector more clearly. I also like that they can be used with any metal detector as long as it has a quarter-inch headphone jack, not just Garrett detectors. Finally, the padded earpieces are comfortable, even for long-term wear.
Conclusion
Metal detectors rely on batteries to get the power they need to sense metals and send signals to the user. Most metal detectors use AA or 9-volt batteries, although some use D-batteries. Most metal detector manufacturers recommend using alkaline batteries for the longest life and best performance. You can increase your metal detector’s battery life by using headphones, using the lowest effective sensitivity setting, and avoiding trashy areas.
