Man do I need help--Suitcase Stereo batteries.UGH!!!

[Jimmer2000]

Hi Everyone.

So glad to found this site. Perfect for my new venture...SUITCASE STEREOS.

So, of course we have all seen the BOOM Cases...and I wanted to build a few ...see how it went. Everything is fairly straight forward..EXCEPT.....THE BATTERY.

Boom Case says their suitcases weight less than 20lbs...my 12v 40AH wheelchair batter weighs 27! not to mention two amps, 6 speakers etc. This thing is going to weight 75lbs..

I am begging you guys...does anyone know his secret? All I can come up with is an IPAD battery? Man...so glad I am here.

Best to all,

JC

 

[ingenieus]

NiMH or Li-Ion (iPad, cell phone etc.) batteries will certainly do the trick but it will not be cheap. Look at the price difference between a Prius and a Corolla to see what I mean.

How much power do you want your amplifier to deliver? This will help to determine what the capacity of your battery needs to be.

An ideal class B amp is about 75% effective. That means that a 30W amp needs a 40W power supply. For a 12V battery this means 3,3A. That means your 40Ah battery will last about 12 hours, but you can only do that if the battery is designed for deep discharge cycling. A car battery can not handle this, but your wheelchair battery should be OK.

A class D amp is more effective at 90% or so, but not really for the aspiring DIYer (I suspect that I am about to be corrected on this). An off-the-shelf class D car amplifier will help extend battery life, but I have no idea on what is available. A quick look on Google only turns up 400W (and up) class D car amps and this will drain your battery in no time flat.

 

[Jimmer2000]

Hi ingenius,

Thanks for the reply. Well...I have 2 X 100 amps I am using. SO...it will have to be those. I need a light solution for a low weight 12v 40AH battery. I was thinking IPAD.

Thanks!

 

[theAnonymous1]

OK, so ipad batteries are 3.7V 5400mAh and cost around $65 each. You would need around 30 of them for 54Ah @ 11.1V. That comes to, oh....... $1,950.

Sure that's still a good idea?

 

[infinia]

you want sealed lead acid batteries aka SLA
they come in a multitude of sizes
1 of these should do the trick Universal Battery UB12220 Sealed Lead Acid

of course you need to read about charging and discharging them so they can last\.

 

[Jimmer2000]

Thanks INF. Why is everyone suggesting deep cycle? This will be a re-chargeable stereo....I would love to use a SLA....lighter, and certainly cheaper. THANK!!!!!!

 

[sofaspud]

Have you listened to this Boom Case? Maybe that's his secret... it's 20lbs of wretched audio.
200W... 6 drivers.... this doesn't really seem like a portable system.

 

[infinia]

deep cycle is constructed for long deep discharges as opposed to a starting battery for high amps for a short time. AH amp hours is the key, note for long life you dont want to exceed about 1/2 of its rated capacity..

 

[sofaspud]

Everyone is suggesting deep-cycle because that is the proper type battery for this application. Ordinary car batteries like a constant voltage ('float charge") and minimal cycling. Their life is shortened when called upon to supply long-period drain. Deep-cycle are made to drain between charges. Have you looked at something like a trolling motor battery for small john boats?

 

[Jimmer2000]

This is great guys. Keep it comin. Sofa, I have looked at every deep cycle battery I can think of. Wheel Chair, Tractor, Moto, Marine etc. The 40-50 AH models not only are very expensive...but CRAZY HEAVY. Guys, please check out this link. This is a REAL head scratcher to me. Under 20lbs...with 8 hours of playing? I can't figure it out.

About | The BoomCase? by Mr. Simo

THANK YOU!!!!!!!

J

 

[infinia]

8 hrs it depends on many factors, BTW the adverts promise my laptop computer lasts 4.5 hrs and my car can get 40 mi/gal..... haha they lied , its really 1/2 of that.

 

[BudP]

What about industrial (2X the life of retail units) AA size LION batteries in a series parallel package as used in older lap top (not) computers. No doubt you could set up your own "pack" for just the power you need without the weight. Then, when cost becomes a factor, do the same thing with AA nicads.

As for the amp, take a look at the chip amps, some of them are extraordinary sounding. PM TerryO here on DIY for some pointers.

Bud

 

[infinia]

all yer Q's esp the one you have not asked yet are answered in the "Boominator" thread.
SLA batts
Class D amps
pro 10" woofers

 

[sofaspud]

Mainly I use cases that are built with wood and leather because of the superior sound they produce.

The "mooos" have so much more clarity. 🙂
It's a bit difficult finding anything technical on thie site. Here it says,
"Double Battery Capacity: $45 (15+ Hours of Battery Life. Adds 3lbs)
So 3lbs of battery added 6 hours of play time. I would guess a 12V 4Ah SLA weighs about 3lbs. The math doesn't look so good, especially at anything close to 100W.
Anyway, the heaviest version is 30lbs, so guesstimating 5lbs for suitcase & Class-D amp and 5lbs of drivers, that leaves 20lbs for a battery. Save the 27lb battery for a smaller unit with extended play time (while still staying within a weight limit).
Or find some good lighter weight drivers.

 

[Saturnus]

all yer Q's esp the one you have not asked yet are answered in the "Boominator" thread.
SLA batts
Class D amps
pro 10" woofers

I can only concur. I know it's a long loooong thread but there's all the answers to everything you never thought about asking.

http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine.html

 

[Jimmer2000]

Wow...that thread is fantastic. I will send him my compliments So let me get this straight. please pardon my newbieness. There are chip amps, that provide the almost the same power needed to drive speakers...they draw very low voltage...so I can use a much smaller battery solving my problem. Is that correct? Now I need some feedback on these mini bad *** amps. WOw. Really? That is a game changer.

 

[Jimmer2000]

So my consult on this project just posed a question. Do these micro amps draw the same amount of power as a car audio amp? Please bare with me...I am pulling my hair out as a newbie...I am sure you get it. Here is what I am considering buying..

4*100W TK2050 TP2050 Tripath D-class Amplifier Board | eBay

This paired with a battery (no idea) running 2 tweets... 2 mids and a 10in sub. Possible?

 

[kevinkr]

I'll hazard a guess that the amplifier is a relatively low powered class D affair, probably well under 20W a channel, and that most of the weight is in fact batteries.. Think little tripath power amplifiers and you will be on the right path.

I think you might find many of the answers you seek in this thread, be warned it's been around for a while and is loaded with posts: http://www.diyaudio.com/forums/class-d/104402-boominator-another-stab-ultimate-party-machine.html

 

[theAnonymous1]

A car amplifier (with the power levels you had in mind) will draw more current from a single 12V battery beause they include a switch mode power supply to boost the voltage.

If you look at the 4*100W board you mentioned, it needs a 30V supply for the stated power output.

So, to use that board to it's full potential, you either need a 12V battery plus a way to boost the voltage, or two batteries in series and live with a slightly lower output.

 

[Jimmer2000]

Oh jessh. I am lost. So...would a 12v 10ah battery work? I need some help. I have many different answers with no resolve. eh..now I am wining.

Thanks Anon.

JC