Wiring help - diyAudio
Go Back   Home > Forums > Design & Build > Construction Tips
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Construction Tips Construction techniques and tips

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 28th August 2014, 09:14 AM   #1
diyAudio Member
Join Date: Aug 2014
I have no idea what is going on (I can't see either post anymore), and I apologise for excessive posting, but here's the original message:

Hi guys,

I'm currently in the planning/semi-begun-building stage of my first DIY audio project, which is in the form of a portable boombox based around the lepai 2020A+ amp and the Sure APT-X Bluetooth 4.0 module. Despite searching the entire internet up and down, I just can't seem to make the electrical/power side of the wiring clear in my head. And to be honest, I'm a little worried about burning a house down/killing a battery and would be very grateful for some help.

I'm looking at incorporating a cig lighter 12v socket for charging accessories like phones/audio players/whatever through a classic car to usb device as the stepdown, as well as a 2.1mm DC jack that can be used to charge the battery via AC mains (240v in Australia) as well as via a small 7.5 watt solar panel I already own. I am sort of hoping that I could be playing music and charging accessories while the solar panel or AC mains is plugged in... basically I can have anything plugged in/not plugged in/left overnight by accident and the house wont burn down.

I have attached a mock wiring diagram that worked in my head, but I really do doubt if this is acceptable. There are also a couple of components I have left off there because I simply wasn't sure where to put them.

The first is a simple power switch, so that when off nothing can drain the battery. Is this a simple case of wiring in line on the positive lead between the battery and the solar charge controller?

The second is a small volt/ammeter (DC 4 5 30V 0 50A RED LED Digital Volt Meter Ammeter Voltage AMP Power NEW | eBay) that I would desperately like to use to know both when the battery needs recharging, as well as how much current the amp is drawing. I have absolutely no idea where to begin with this one. The yellow wire is scaring me even though the product hasn't arrived yet! Can anyone help with this?

I hope you understand my misunderstandings, and that they haven't been answered to death.

  Reply With Quote
Old 28th August 2014, 10:16 AM   #2
diyAudio Member
Join Date: Aug 2014
I'm so sorry for all this, but here's the professional standard attached wiring diagram.
Attached Images
File Type: jpg possible_wiring.jpg (758.3 KB, 130 views)
  Reply With Quote
Old 4th September 2014, 02:13 AM   #3
diyAudio Member
OffGridKindaGuy's Avatar
Join Date: Apr 2013
Location: Tuscarawas County, Ohio
I see your solar charge controller has an "Array", "Load", and "Battery" connection. First question.. What is the exact controller you have? (Make/Model)

Usually, "Array" is for connection to the solar panel(s) only. "Battery" is for connection to the battery only. "Load" is for connection to all loads from the battery..

Sometimes when a charge controller has a "Load" connection, it's a controlled output for possibly a Day/Night sensor for lighting or whatever, and other times it's just a simple connection to loads, using the maximum current rating of the controller to protect the battery from a dead short..

A separate circuit will be the charge for the battery from the mains. That should be totally outside of the charge controller. The only function for the controller is to control the charge from the solar array to the battery..

Personally, I wouldn't mess with the load connections on the controller and bring all of your loads directly from the battery..

A 7.5 watt panel isn't going to be much charge. (Less than 1/2 amp at full sunlight)

What size/type of battery are you going to use?

Give me more information and I can help..
  Reply With Quote
Old 4th September 2014, 03:17 AM   #4
diyAudio Member
Join Date: Aug 2014

Thanks so much for the reply.

This is the exact model I bought: 20A Solar Panel Battery Charge Controller 12V 24V Light AMP Time Regulator 240W 480W | eBay

I noticed that its a 20A, which is a fair bit higher than anythign I'm going to put through it... is that going to be a problem? Yes, when I read the instructions the load connection has a whole bunch of timer settigns based around once there is no light. There doesn't appear to be an 'always on' mode for the load so I assume its useless for me.

I sort of thought that a charge controller would act the same as a SLA battery charger does and turn the mains to trickle charge when the battery was full. Is this not the case? If I have to run a separate circuit for the mains, does this mean I'll need a SLA battery charger as my power supply?

I was planning to find out exactly how much current the amp draws when playing music at high volumes with my speaker set up using the voltage/ammeter I linked to in my first post before I decided to exactly what battery I'm going to use. But I was planning on a SLA of around 9 - 15AH. I do realise the weights involved here.

Yes, after playing with my charge controller and that solar panel I couldn't even get it to charge the battery. Is this because 0.5a is just way too low for the 20a charger? I also have a feeling the solar panel might have seen its last day nearly... it was struggling to power the little LED on the panel in some cases.

I was looking at something like this as a replacement: Portable 18V 28W Folding Solar Panel Charger Battery Dual Output Controller Pack | eBay

Would that be suitable? I see its 18v... does this mean its max output under high sun is going to be much higher than that? Would this cause problems? Or can the solar charger sort that out cause its 12/24v?

I hope this is enough information, and thanks so much for the reply! I was just about to give up and assume I'd commited some sort of DIY forum faux pas.
  Reply With Quote
Old 4th September 2014, 10:30 AM   #5
diyAudio Member
OffGridKindaGuy's Avatar
Join Date: Apr 2013
Location: Tuscarawas County, Ohio
The charge controller that you have will work. An overkill but OK. I would avoid the load output connection and put all loads directly to the battery..

The 28 watt panel will work fine. It may provide ~1.5 amps in full sunlight. (Depending on conditions) That's plenty to charge a SLA type battery. Slow charge, which is good. Just install a 100 ohm 5 watt resistor between the controller and the battery to buffer the current a little..

18 volts isn't too high for that controller. It will be fine. Some 12 volt panels put out 20 volts open circuit. The controller should select the proper charge voltage when you connect a battery to it. Read the instructions to be sure..
  Reply With Quote
Old 22nd September 2014, 11:23 AM   #6
diyAudio Member
Join Date: Aug 2014
Thanks again for your help, and sorry for my disappearance. I have been a little busy

So all the parts have arrived and I've been playing around and fiddling to make sure everything is working. When I was playing with the volt meter (mentioned in the first post) I decided to see how many amperes the amplifier would be drawing at higher volumes, and was a little shocked to see it was around 90 or so according to the meter. Is that as ridiculously excessively high as I think it is? The wire I'm using was just some 'auto-cable' I had lying around, and says its rated to 10A. Am I likely to start a fire or something like this? I let it run for about 3 minutes and nothing seemed to be getting warm, but it made me really uncomfortable still.

Apart from that, things appear to be going well, and I think I've got my head around it all now.

  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Wiring a line array: altering wiring schemes for matching levels w/woofer dave251 Multi-Way 6 5th February 2014 01:21 AM
Need Wiring help benk016 Subwoofers 11 12th August 2011 11:23 AM
Inner wiring master_pogus Parts 4 28th November 2005 01:05 PM
Focusing on wiring cable for gainclone!!!Share ur experience in wiring cable.... thomgun_lc Chip Amps 38 31st August 2005 02:46 PM
I'm wiring my 4 channel 8 parallel LM4780 boards... check my wiring :) Audiophilenoob Chip Amps 9 16th August 2005 04:37 AM

New To Site? Need Help?

All times are GMT. The time now is 02:40 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2