This is a 9V battery pack with on/off switch and a pre-attached 5.5mm/2.1mm center-positive barrel plug. Use this to battery-power your Arduino (or other electronic projects) - it's ready to go out of the box! Battery & screw not included.

I found these high-quality battery clips. They're molded plastic so they wont tear like cheap clips, and they cover the battery terminals to prevent shorts. Comes with a 5.5mm/2.1mm center-positive barrel connector, assembled! Battery not included

This tiny coin cell battery holder is ideal for small portable or wearable projects. It holds two 20mm coin cells (2032 are the most popular size) in series to generate 6V nominal. (If you want only 3V, we suggest sticking a crumpled piece of tin foil in one of the slots.) 20mm coin cells are popular as they are used in keychain lights, so they are easy to get, and fairly low cost. They tend to have about 220mAh capacity so this holder would...

Make a portable power brick with plenty of juice! Use Alkaline AA's for a 9V 3000-4000mAh power supply, or rechargeable NiMH for 2000mAh 7.5V supply. Either one is good for running electronics that have a 5V voltage regulator (thus requiring a 7V+ supply). Will last about 10 times longer than a 9V Perfect for portable Arduinos! Batteries not included

Make a portable power brick with plenty of juice! Use Alkaline AA's for a 12V 3000-4000mAh power supply, or rechargeable NiMH for 2000mAh 9.6V supply. Either one is good for running electronics that have a 5V voltage regulator (thus requiring a 7V+ supply) or perhaps some motors or solenoids. Perfect for portable Arduinos, motors, solenoids, 12V LED strips, etc. An On/Off switch lets you control the power right at the source without unplugging....

This battery holder is by far the easiest way to add a battery to a small wearable project. By coincidence, there are two small 1mm diameter holes in the metal connection tabs, just large enough for a #5 or smaller needle to pass through. One tab connects to common ground (negative) and the other tab is +3 Volts. This holder is meant to be used with Lithium CR2032 (20mm diameter, 3.2mm thick) sized coin batteries. These are almost always 3V at...

Make a nice portable power pack with this 4 x AA battery holder. It fits any alkaline or rechargeable AA batteries in series. There's a snap on cover and an on/off switch which can be handy when wiring to something without a switch. The four batteries are held in series, for a nominal output of 6V DC for alkaline (6.4V when fresh, 4V when dead), and 4.8V DC for rechargeables (5.2V when fully charged, 4.4V when discharged). Using...

This battery holder connects 3 AAA batteries together in series for powering all kinds of projects. We spec'd these out because the box is slim, and 3 AAA's add up to about 3.3-4.5V, a very similar range to Lithium Ion/polymer (Li-Ion) batteries and have an on-off switch. That makes them ideal for use with 3.3V projects that have a 2-pin JST connector meant for one of our Li-Ion/Poly batteries. (Of course, you can't recharge them...

When you need a portable 12V power pack, this big holder will do the job! The holder will store 8 AA batteries end to end, to give approximately 12VDC output with up to 2 amp peak current draw. We like this configuration in particular because it holds the batteries securely, even if being bumped/moved around. This would make a good power source for EL panels, 12V stepper motors (for a robot), or analog LED strip such as this 30 RGB LED, 60 LED...

Simple but effective - this sewable breakout board has a CR2032 coin cell battery holder soldered on, an on/off switch and 0.1" pitch breakout pins for easy connecting. Great for powering very low-current projects, or adding a battery backup circuit to a real-time-clock or similar. There's two ground pins, one 'switched' power pin, and one pin that is always on. Comes with one fully assembled and tested breakout plus a small...

Keep your power source safe and toasty in these waterproof 2xAA battery holders. They're just like classic switched battery holders, but designed for survival! The case has a rubber gasket around the edge of the case (its black and hard to see in the photos but it is there) and attaches together with 4 machine screws. What we like about this design is that the hexnuts are captive in one side and you can assemble/disassemble as many times as you...

Keep your power source safe and toasty in these waterproof 3xAA battery holders. They're just like classic switched battery holders, but designed for survival! The case has a rubber gasket around the edge of the case (its black and hard to see in the photos but it is there) and attaches together with 4 machine screws. What we like about this design is that the hexnuts are captive in one side and you can assemble/disassemble as many times as you...

This switched JST connector is the best way to quickly prototype with our LiPoly batteries. We paired a genuine JST connector with a slide switch that can do up to 600mA. Both are soldered onto a breadboard-friendly breakout. There's two ground pins, one 'switched' power pin, and one pin that is always on. This is compatible with the "JST PH 2-pin" connectors we use in our battery packs.. Mates perfectly with all our 1-cell...

A simple 2-pin connector that is compatible with the "JST PH 2-pin" connector - perfect for soldering to the bottom of our 3.3V Logic Trinket and 5V Logic Trinket! These mate perfectly with all our 1-cell LiPoly and LiIon batteries as well as our 6V coin cell holder and 3xAAA battery pack. We also have simple JST pigtails that mate with this connector. Note : This product might be black or tan.  We cannot control the color you'll receive!

Simple but effective - this sewable breakout board has a CR2032 coin cell battery holder soldered on and 0.1" pitch breakout pins for easy connecting. Great for powering very low-current projects, or adding a battery backup circuit to a real-time-clock or similar. Comes with one fully assembled and tested coin cell battery holder and a small stick of 0.1" header so you can solder it on and plug into a breadboard. Coin cell battery is...

A simple 2-pin connector soldered onto a breadboard-friendly breakout. This is compatible with the "JST PH 2-pin" connector. Mates perfectly with all our 1-cell LiPoly and LiIon batteries as well as our 6V coin cell holder and 3xAAA battery pack. We also have simple JST pigtails that mate with this connector. You may get an off-white or black JST connector.

Simple but effective - this breakout board has a CR1220 coin cell battery holder soldered on, an on/off switch and 0.1" pitch breakout pins for easy connecting. Great for powering very low-current projects, or adding a battery backup circuit to a real-time-clock or similar. There's two ground pins, one 'switched' power pin, and one pin that is always on. Comes with one fully assembled and tested breakout plus a small stick of...

Simple but effective - this breakout board has a CR1220 coin cell battery holder soldered on and 0.1" pitch breakout pins for easy connecting. Great for powering very low-current projects, or adding a battery backup circuit to a real-time-clock or similar. Comes with one fully assembled and tested coin cell battery holder and a small stick of 0.1" header so you can solder it on and plug into a breadboard. We also have a version with an...

This is an interesting kind of battery holder, usually you'll see ones that are designed for holding like AAA's or something. This battery holder is designed to clip into and hold camcorder batteries. Specifically, the common SONY NP-Fxx series of batteries and compatibles, made with cylindrical LiIon cells and 7.4v nominal output. By clipping a battery in, you can use this holder to plug into any device with a 2.1mm DC jack that wants...

This is an interesting kind of battery holder, usually you'll see ones that are designed for holding like AAA's or something. This battery holder is designed to clip into and hold camcorder batteries. Specifically, the common Canon LP-E6 rechargeable Lithium-Ion Battery Pack (7.2V, 1800mAh). We also have a holder for the SONY NP-Fxx series and Pansonic CGR-D28/CGA-D54 series. Comes with just the plastic holder, six screws, and cable...

This is an interesting kind of battery holder, usually you'll see ones that are designed for holding like AAA's or something. This battery holder is designed to clip into and hold camcorder batteries. Specifically, the Panasonic CGR-D28 (7.4V, 3300mAh) and CGA-D54s (7.2V, 5400mAh) Lithium-Ion Battery Packs. We also have a holder for the SONY NP-Fxx series and Canon LP-E6 series. Comes with just the plastic holder, six screws,...

Here's yet another addition to our family of AA battery holders. It's a holder for five (5) AA batteries, with 5" wire leads. It's black and has a 2.1mm barrel plug (tip positive). 5 x AA battery packs are best used with Arduino-compatibles and other dev boards with 2.1mm DC jacks and a 5V regulator, because 5V regulators tend to like 1-2V of overhead. 4 x AA battery holders would give you ~6VDC, which is just a tiny...

This battery holder connects 3 AA batteries together in series for powering all kinds of projects. We spec'd these out because the box is compact, and 3 AA's add up to about 3.3-4.5V, a very similar range to Lithium Ion/polymer (Li-Ion) batteries, plus it has a nifty on-off switch. That makes them ideal for use with 3.3V projects that have a 2-pin JST connector meant for one of our Li-Ion/Poly batteries. (Of course, you...

This battery holder connects 3 AAA batteries together in series for powering all kinds of projects. We spec'd these out because the box is slim, and 3 AAA's add up to about 3.3-4.5V, a very similar range to Lithium Ion/polymer (Li-Ion) batteries, plus it has a nifty on-off switch. That makes them ideal for use with 3.3V projects that have a 2-pin JST connector meant for one of our Li-Ion/Poly batteries. (Of course, you...

Are you tired of having to accommodate inconvenient power supplies and compromise the mobility and customization of your project? The BooSTick from Rover Development might be just the thing you need! This tiny board allows you to bring the power to your project, and not the other way around. Bring your micro to the sensor without running wires! A single AA battery is used to provide breadboard power of 5V or 3.3V (or other voltages by...