The BeagleJuice 2 is the latest of Liquidware’s expansion modules designed for use with the BeagleBoard. This upgraded version packs a serious punch and can be likened to a laptop battery. It shares the same form factor as the original BeagleJuice, so if you find yourself needing portable power, the BeagleJuice 2 is definitely the way to go. If you find you need more portable power, the BeagleJuice 2 High Capacity offers an impressive 8,400mAh charge capacity. 

Like its predecessor, the BeagleJuice 2 makes the BeagleBoard (or PandaBoard) portable. A battery module that provides a quad output 5V power supply directly to the BeagleBoard, it can be mounted onto the back side using standoffs, which keeps the expansion ports easily accessible.

The 4200mAh Li-ion battery is charged using specialized charging circuitry that boosts performance for longer-lasting applications. The module itself can supply power through a special, 2-pin barrel jack, or directly through wires on dual pin headers. It can be charged using a 19V power adapter for accelerated charging.

Like most portable, handheld devices, the BeagleJuice 2 can provide power while plugged in, and there’s an on/off switch to make booting and shutting down simple. Best of all, the modular form of the BeagleJuice 2 fits with the BeagleTouch to sandwich the BeagleBoard – resulting in a solid, handheld Android or Linux-based computer in the palm of your hand.

Specifications

• 4200mAh battery (or 8,400mAh for the High Cap)
• Quad 5V output
• 4A Current delivery
• Max Current Rating: 4A sustained 5A Max (from peak load spikes)
• Powers a BeagleBoard for at least 10.5hrs (20hrs with the High Cap)
• Powers up to 4 BeagleBoards
• Pin-headers to provide direct power supply for any application
• 19V power supply (with a 2.1A current rating) included
• Battery charge status LEDs
• Button controlled battery power level LED meter
• 4 mounting standoffs included
• On/Off switch

Dimensions 

Beaglejuice 2 (MeCap)

• 4.104'' x 3.1'' x  .479''     104mm x 79mm x 12.2mm         
• 4.3 oz   123g  

Beaglejuice 2 (HiCap)

• 4.104'' x 3.1'' x .672''      104mm x 79mm x 17.7mm
• 7 oz     199g   

Beaglejuice (Original) and Beaglejuice 2 Specs Comparison

  BJ model comparisons.pdf

                              BeagleBoard xM mounted on BJ2

                                BJ2 (Top image) 

                           (Left) BJ2 MeCap and (Right) BJ2 HiCap (back image)

I have a first-gen BeagleJuice, why I should upgrade to the 2nd gen?

Long story short, we designed the BeagleJuice 1 to be a quick prototype to power a BeagleBoard. We designed the BeagleJuice 2nd Gen to be a power supply that can deliver large amounts of currents for long periods of time (we use a similar design for 2 military customers requesting the technology). So, if you're looking for a long-lasting, powerful portable power supply, an upgrade to the 2nd Gen will definitely be worthwhile.

The original BeagleJuice is rated at 4500 mAh, while the MeCap is rated at 4200 mAh. Does that mean my original BeagleJuice has a longer battery life than the MeCap?

The BJ2 was designed with a great deal of "efficiency" considerations, and will perform better than the original BeagleJuice. Also, lithium batteries tend to depreciate in capacity by about half every 20 months, so the simple fact that the BJ2 is newer means it will last longer.

What are the charge times for the MeCap and the HiCap? (comparing USB and 19V adapter)

The 2nd Gen can only be charged from the 19V power supply (which is included in the order of a 2nd Gen and pictured below). The 2nd Gen charge times vary depending on the load. If you are powering a BeagleBoard xM and a BeagleTouch, the charge time will be 3.5 hours for the MeCap BJ2 and 7 hours for the HiCap BJ2.  

If you need to do this for a more sustainable product, than you can connect to

the BJ2s I2C bus and actually program and manage the charge currents and saturation points (this will cut the charge times in less than half).

The comparison sheet on the Wiki rates it at 10 hours including LCD use (I presume that means 10 hours of idle time?)

That is 10hrs of display and 1GHz processor "on" time. If you allow it to idle, you can stretch the life significantly.

How can I figure out how much charge my 2nd Gen has?

One of the neat new features of the 2nd Gen is the button controlled charge level power meter. When I press a button on the board (picture below) the LEDs will light and indicate how much charge the battery currently holds. 

How many BeagleBoards can I power simultaneously with the BeagleJuice, 2nd Gen?

The short answer is 4 boards. There are four 2-pin 5V output connectors on the 2nd Gen, so you can use those and the barrel adapter cables that are included in the order. You can use any combination of 4 boards you can think of (I've included some pictures of how you might mount different boards to the 2nd Gen)  and have them all simultaneously powered by the 2nd Gen. Below is a video of me powering an Arduino Uno, a BeagleBoard C5, a BeagleBoard xM, a BeagleTouch (mounted on the C5) and a PandaBoard ES.

How do I wire my barrel jack and cable together so I can provide the 19V needed to charge my LoCap BJ2?

1. Split one end of the cable about a 1/4 inch down and strip

either end.

2. Pass the cable through the bottom of the                    3. Solder the negative end of the cable to the top

barrel jack and out the top.                                            hole of the metal part and then close the clamp on the cable.

                                                                                  4. Solder the positive end of the cable to the second hole of the metal part.

Pandaboard mounted and powered by BJ2

          BJ2 and Arduino Uno

    Velcros attached to BJ2 and Arduino Uno

            BJ2 powering Arduino Uno

                 BJ2 and Arduino Mega 2560

      Velcros attached to backside of BJ2 and                      Arduino Mega 2560

            BJ2 powering Arduino Mega 2560

        BJ2 and Beaglebone (Top view)

              BJ2 and Beaglebone (Side view)

             BJ2 powering the Bealgebone