Introduction: MusicTank Mk. III

About: Oi I'm a senior double major of T.V. production and History at Hofstra University. I love making stuff, my recent project was a solar powered speaker system in the shape of a tank... I am continuing innovati…
The MusicTank is a previous invention of mine; it is a Solar Powered Stereo System in the shape of a Sherman Tank.  Since the creation of the Mark. I on March 15th, 2010, the MusicTank has undergone three major upgrades.  This Instructable will follow the third and most significant upgrade to the invention.

The idea of the MusicTank came from the desire to have the electronic luxury of stereo amplification in a wireless, mobile, and most importantly self reliant design.  The Mark III expands upon the original design offering a Deeper Battery Well , home made Solar Panel , and a high watt 12 - 110 Power Inverter .

These upgrades turn the Tank into a small power generator offering 400 continuous watts per hour at 110v from the battery well.
By making the solar panels myself i cut down on the cost of the solar panel. it was extra work but I was able to create a high watt panel for a fraction of the price than a manufactured one.

                                         There are numerous Instructables on making your own solar panels:
                                         Also some Instructables on recycling and reusing broken solar cells:
                                                    (Its more delicate work but Fortune favors the Bold )

Step 1: New Circuitry

As I mentioned before this is an upgrade to a previous invention The MusicTank  

That being said I can skip through the basic construction.  This is an upgrade the Mk. II to the Mk. III

New features to the Mk. III:

- Bigger more powerful Battery Well

- Total control of electronics through the trunk

- On / Off toggle switch and a protected circuit

- Household power ! by the means of a 2 plug 400 watt inverter

- Arduino controlled light system

-A firing cannon 

Step 2: Designing the Batter Well

after field testing the Mk.II; we kept hitting a roadblock with our battery. The system was running on a 12v 18ah battery supporting a load that was 50 watts+ per hour and the solar panel that was supporting the system only pumped 5 watts per hour back into the Battery Well.  This only allowed for about 5 or 6 hours Max playing music from the amplifier... 

We need MORE POWER ! !

The new Battery Well solves this, by wiring similar 12v batteries in parallel we combine the number of Amps, this creates a deep well of potential electric power.  By deepening the amount of potential energy, we multiply the length of time the system can be used.  With a combination of a deeper Battery Well and a Panel that outputs at a higher wattage we will have a Self Sustaining System .  

I added a 40 amp 12v battery that was 8" wide 6 1/2" long and 7 " tall
fitting it perfectly under the suspended charge controller.
The new battery will be the primary battery in the battery well (battery bank), it will be wired first in the bank and will get the most use for this reason. the batteries will be interconnected with no less than 8 AWG wire cut to fit with 8 AWG ring terminals connecting to the battery terminals.   I found a battery that fits perfectly well but before you secure it to the structure you must wire and place the ON / OFF switch and other wiring.

Step 3: Creating the Solar Panel

There are many DIY walk throughs on how to create your own Solar Panels here are a few on Instructables i found interesting;

by following these you will have a rough understanding of how to build you own Solar Panels from the ground up
obviously the size of the array you create will correspond to the amount of power is is able to produce.  You must create an array that fits the size of your creation exactly; you can get creative with your placement of the panel and even have a larger panel independent of the tank.  Most important to the upgrade in the Mk III MusicTank was the ability to use the system free of recharge and fully solar.  The solution to this was either:  

1) add to the Battery Well of "potential energy"

2) construct or purchase a solar panel that has a comparable hourly charge rate (in Watts) to my Amplifier (50 Watts/per hour)

I decided to do both, adding a 40 Ah battery to the Well and building a 50+ Watt panel

You can build your own panel from the ground up or you can purchase a manufactured panel from sites like Jameco
just be sure that whatever panel you choose to use, it must be able to fit securely on the back of the panel.

Step 4: Arduino Controlled Light System

Having a larger Battery Well mean we can distribute power elsewhere and more because we have more of it, "Potential Power"

With this we can run The MusicTank after dark without having to worry about the system cutting short.  I decided to add a programmable light system to the Tank, I wanted to make it as appealing playing music when the sun goes down as when it is bumping in the sun.

To do this I piped 3mm EL wire along the edges of The MusicTank,  the lights are controlled by an Arduino Uno system, sequenced by a EL Escudo, and powered by a 12v volt inverter 

Materials for this Add on:

- EL Escudo

- Arduino Uno 

- 12v to AC inverter

- 8 Pin Spacers (x8)

- 20+ ' of EL wire (color of your choice)

- knowledgeable computer programmer

I will finish this section later in the month if there is enough want.  There are many Instructables regarding EL Wire light systems look to those for completing this add on, what makes this design unique to other is the fact that it draws its power from the Solar charge controller :)

Step 5: Creating the Air Cannon

The Cannon functions by firing a projectile at high velocities from the self contained air cannon mounted in the turret of the MusicTank.
The cannon uses air pressure stored in the air reserve tank , and pressurized by an electric solenoid quick release valve this valve releases after the completion of 2 circuit switches located under the air reserve tank.

The first switch will "arm" the cannon, a green LED will indicate this

The second switch will "fire" the cannon, a red LED will indicate this as well as the cannon firing 

*Refer to pictures number 1, 5, and 6 for a reference

Step 6: Wiring It All Up

I began by wiring all of the positive connections(+) to the ON side of the Heavy Amp Switch  this includes positive connections from all components:  

1) amplifier
2) status light
3) Inverter

After these are connected and tightened insulate with liquid tape
Connect the other side of the switch to the 50 amp circuit breaker with 8 AWG w ire ( Wire must be pre - cut and the ring terminals must be attached before you connect them )

Next connect all of the negative connections (-) to the NEGATIVE (-) terminal of the battery 

- Status light
- Inverter
- Battery Well *
- Solar Charge Controller **

*add an extra 8 AWG wire with ring terminals connected to the negative side [see picture] this trailing wire is the (-) Battery Well connection. This wire should be about 8" or so it can be snaked to fit.  It will be connected to the secondary battery in the well

** also wrap 14 AWG or 12 AWG wire around the terminal and connect the other end to the (-) terminal of the battery slot on the Solar Charge Controller

The last wire to connect will ready the system, these are the connections to the positive terminal on the battery.
ready this by connecting some 8 AWG wire from the Circuit Breaker to the (+) positive terminal of the battery. 

*add an extra 8 AWG wire w/ ring terminals connected to the positive side, this trailing wire will be connected to the secondary battery in the well.

** Also wrap 14 AWG or 12 AWG wire around the terminal and connect the other end to the (+) terminal of the battery slot on the Solar Charge Controller

The first picture is a diagram of the circuitry

Connect the secondary battery by screwing down the trailing 8 AWG wires to their respective terminals ( if you choose not to connect a secondary battery TAPE OFF the trailing wire THEY ARE HOT

Step 7: MusicTank Mk. III

Now you have a Mk. III version of the MusicTank , functioning not only as a solar powered stereo system but also as a small power generator. 

What if you are in anyway interested in The MusicTank but do not feel up to the task of creating one yourself... Not a problem,

*Starting this summer at  we will offer consumer versions of The MusicTank for sale on our website as well as quotes on custom solar powered stereo systems*; we love new projects and welcome creativity.  Reach us at

 Mike Mikula
President of InfluenSol

Here is a short documentary featuring my company InfluenSol, our products, and our mission statement.  Shot and put together by In & Out of Focus

Some great shots of the MusicTank firing. Enjoy