azisme

I am trying to figure out what size battery I need in amp/hours and maximum discharge current to power an audio amplifier.

The amplifier that I will be using is an old cheapo Jensen XA184. I could not find any info on it, but I did find a datasheet for the power chips that the amp uses. Here is a link to download a pdf of the datasheet: https://www.datasheetcatalog.com/data...TDA8560Q.shtml

The amplifier is 4-channel so the power requirements for the chip will need to be doubled. I am looking to get a play time of one to four hours. I am looking at lithium, NiMH, and SLA technologies.

JinbaIttai

You're going to put a sound system on your bicycle? Where will the sub go?

BroadwayJoe

Will depend how loud you turn it up...

azisme

Oops, I posted the wrong link. Here is the link I meant to post:https://www.datasheetcatalog.com/data...TDA8560Q.shtml

Here is a link to the subwoofer I plan to use: https://www.mavin.com/index.php/produ...tput-96-db-spl

And a link to the full range speakers: https://www.etronics.com/p-23279-pyle...-speakers.aspx

And the tweeters: https://www.etronics.com/p-23376-pyle...eter-pair.aspx

I am going to mount the speakers in a Nashbar front bag. I will build a custom box for the woofer that fits inside the bag. The mids and tweets will fit in the side pockets. The amp mounts directly on the rack under the bag while still providing adequate airflow. The music source will be a mp3 player powered with its own internal batteries. Over 10 miles of my 15 mile commute is on a trail where I will not be bothering anyone with the noise. When I am on busy streets it will be turned down low for my own safety.

BroadwayJoe

You might find it safer to have it cranked on busy streets... People often have no idea we're riding by them and seem to step in front of us at the worst possible moments? This issue will continue to plague bicycles and other EV's for years to come.

You're really not gonna know how much power you need until you put it together and use it at the sound levels you use it at. You can possibly calculate a worst case scenario but your links don't work and we have no idea how much current the amp is likely to draw at max volume.

Take worst case current draw in amps from the amplifier. Multiply that by the number of hours it will be used. That will be your AH required - use whatever voltage (assuming 12Vdc) and that's the battery you need.

Probably won't need that much but until you know how long and how loud it actually will be used, there's no way to get closer.

Seriously, figure out the ebike 1st (voltages completely different btw - hope you weren't assuming to use same batteries?) - use earbuds or a Boom-Tube rechargeable speaker system for now until you know more about what you're doing...

crackerdog

Get an Ipod and don't disturb anyone on the trails. Small, convenient, able to be used in many more situaltions and everyone else doesn't have to like your choice of music.

bikingbrit

Like the man said, depends on how loud you play it. My guesstimate:

barely audible: 0.5 amps
fairly loud: 2 amps
really cranking: 7 amps
gross overdrive/distortion: 15 amps

azisme

I will be using an ipod as a music source, but I don't care to use headphones for a few reasons. Mainly because they block the sounds around me too much. I do not plan on blasting the music, and the trail is very lightly used, especially during commuting times.

azisme

My original gut feeling was 4Ah with around 15 amp current. After some more thinking on the current, I now believe 5 to 10 amps would be plenty. In researching battery technologies, I decided to just go with an SLA battery. A 7Ah is pretty cheap and will provide way more current than I need. This should give me around 5Ah of usable energy.

ken cummings

How about going to some big-box store like Fry's or best buy or even (choke) Radio Shack and find a portable and battery operated sound system with the output you plan to use. Just find out what size of batteries it uses, double that to prevent over-discharge and you are good to go.

ianrodness

I've got a pair of Grado Labs headphones I use with my ipod that allow outside noise in. They're super comfortable to wear for extended periods of time, and I'm thinking about mod-ing my helmet to inset the drivers directly into the foam.
I just thought this might be an easier/cheaper solution for you - but if you're determined - best of luck.