Batteries Revisited - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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
Reply
 
Thread Tools Search this Thread
Old 2nd May 2009, 01:21 PM   #1
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
Default Batteries Revisited

My growing awareness of the importance of PS in any piece of analog or digital audio equipment has led me to reconsider batteries again as a PS.

Good PS are not cheap and usually not simple. If we are looking for a regulated supply then these can be as complicated as the equipment they are supplying power to. Also if a PS is found to be good in one piece of equipment it is not guaranteed that it will be good sounding in another.

SLA Batteries were dismissed some time ago as being noisy when current was being drawn. I believe these tests (TNT audio) were done with a single battery? Very low internal impedance of the battery was considered the important factor & only achievable through expensive SLA batteries or paralleling ordinary SLA batteries.

I know this seems just as expensive but there are a lot of batteries thrown out in recycling centers whose only problem is sulphation & these more than likely can be reformed.

Has anybody tested this parallel use of batteries against good quality mains powered PS?
What are the thoughts on this?
  Reply With Quote
Old 2nd May 2009, 01:37 PM   #2
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Just curious has anyone compared deep cycle LA to normal automotive LA? The deep cycle batteries have a much larger amount of lead so survive repeated deep discharge. The action is probably a lot of surface chemistry so it might not matter. Also a new way to spend $$ phone closet and locomotive versions are available at 10000's of A/H and several tons. I have not verified the noise myself.
__________________
"The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important."
  Reply With Quote
Old 2nd May 2009, 01:52 PM   #3
Ziggy is offline Ziggy  Australia
Account Disabled
 
Join Date: Jul 2004
Location: West Australia
Maybe car batteries........believe it or not?

http://www.mother-of-tone.com/byob.htm
  Reply With Quote
Old 2nd May 2009, 01:58 PM   #4
paulb is offline paulb  Canada
diyAudio Member
 
Join Date: Jun 2001
Location: Calgary
Quote:
Originally posted by Ziggy
http://www.mother-of-tone.com/byob.htm
950 Euros for a 10W amplifier without a case...do you think anybody has actually bought one of these?

Back on topic,
Do you have a link for the TNT Audio battery tests?
  Reply With Quote
Old 2nd May 2009, 02:12 PM   #5
okapi is offline okapi  United States
diyAudio Member
 
okapi's Avatar
 
Join Date: Aug 2004
Location: Buffalo
my impression was that TNT tests were done without a capacitor on the output (correct me if i am wrong). I think an output capacitor would make a battery as close as we can get to an ideal power source.
  Reply With Quote
Old 2nd May 2009, 03:57 PM   #6
diyAudio Member
 
Join Date: Nov 2004
Location: Florida
I've used batteries before in parallel with power supply, and it works great! I highly recommend good output filtering in addition to the battery for best results.

I did one power supply with a paralleled 14.4V NiCD battery, and 10,000uf filter capacitor for running a car radio. The peak unloaded voltage of the 2A transformer (~19V) is not enough to overcharge the battery, so it stays cool. When the load got heavy, (more than the rating of the transfomer) most of the time, it would only drop to ~15V where the battery took over, and held the voltage pretty steady, then as soon as the load lightened, the transformer takes back over for the majority of the power.

Another PS I made is for driving 3.7V LED headlights for bicycle. Takes 12V down to 4.2V max, and has a 3.7V Li-Ion directly in parallel, so either the charger and/or battery feeds the load, and the great thing about Li-Ion, is they hold a VERY constant voltage, and don't vary as much as other battery chemistries.

The Lead-Acid battery in your project should be great, but IMO I recommend large filtering capacitors to filter any noise generated either by the power supply or battery.
__________________
You can call me Mad Professor, building crazy experiments in my Electronics Workshop
  Reply With Quote
Old 2nd May 2009, 04:05 PM   #7
diyAudio Member
 
Join Date: Nov 2004
Location: Florida
Quote:
Originally posted by paulb

950 Euros for a 10W amplifier without a case...do you think anybody has actually bought one of these?

Back on topic,
Do you have a link for the TNT Audio battery tests?
$950 for a PCB on a piece of Wood? WTF? That's crazy!

I bet one could be built for less than $20.
__________________
You can call me Mad Professor, building crazy experiments in my Electronics Workshop
  Reply With Quote
Old 2nd May 2009, 05:06 PM   #8
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
I use cordless tools till they get broken, worn out or stolen and go through battery packs like crazy. The latest is lithium-ion and I have 3 packs that are dead. I opened one up and found that only 2 of the cells were toast - the rest were fine.
I've been looking for a holder for these size cells but there doesn't seem to be any (I guess since these cells are used in packs where the terminals are joined with strips that are spot welded on). I could DIY a holder I guess.

Nice to use some of these in a preamp, phono amp or even a low power amp. Should be ultra quiet, no?
Attached Images
File Type: jpg picture 1102.jpg (92.3 KB, 239 views)
  Reply With Quote
Old 2nd May 2009, 05:23 PM   #9
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Can't you just use "AA" battery holder from Keystone Products?
  Reply With Quote
Old 2nd May 2009, 05:28 PM   #10
Account disabled at member's request
 
MJL21193's Avatar
 
Join Date: Mar 2007
Hi Jack,
These are 65mm long and 18mm diameter so quite a bit bigger than AA which are 50mm x 13mm.
  Reply With Quote

Reply


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
PS Audio 200 CX Revisited Don S Solid State 55 7th October 2013 02:52 AM
A75 revisited Peter Daniel Pass Labs 27 8th June 2012 08:34 PM
Build or Buy - Revisited... DIYNewbie Multi-Way 15 26th June 2004 11:41 PM
Revisited Zen seve Pass Labs 6 16th June 2004 10:41 PM


New To Site? Need Help?

All times are GMT. The time now is 12:11 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2