A quick question about battery power - 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 22nd March 2006, 06:38 PM   #1
Thunau is offline Thunau  United States
diyAudio Member
 
Thunau's Avatar
 
Join Date: Mar 2001
Location: PA USA
Default A quick question about battery power

I have two big-a$$ boat 12V batteries that were installed in my basement as a backup power source for a pump. I since fixed the source of the original water breach and have no need for the pump or the backup system.
So, I had an idea to use two good quality 4 channel car amplifiers for my active 3 way speakers and run them from two separate 12V, 100W switching PS, with the boat batteries providing the extra amps if/when needed. The question is, is it safe to paralell the batteries with the switchers? If not, is there a circuit that would make the connection a sound one?
__________________
"Most people just say what they know, the wise ones know just what to say."
  Reply With Quote
Old 22nd March 2006, 07:37 PM   #2
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
I'm not a wise man but I can move your thread to PSU design

/Hugo
  Reply With Quote
Old 23rd March 2006, 01:53 AM   #3
anatech is offline anatech  Canada
diyAudio Moderator
 
anatech's Avatar
 
Join Date: Jun 2004
Location: Georgetown, On
Hi Jan,
I'm sure you will get some answers. Not knowing completely, I'd suggest asking this question of a boat electrical technician. I am sure they have installed systems like these in boats before.

-Chris
  Reply With Quote
Old 23rd March 2006, 04:35 AM   #4
diyAudio Member
 
Join Date: Feb 2004
Location: Racine, Wisconsin
I don't think that I would parallel them. Ultimately one battery will be discharging into the other battery. Keep the amps and the batteries seperated and by a "two bank" charger for them.

http://www.batterystuff.com/battery-...k/GU2607A.html
  Reply With Quote
Old 23rd March 2006, 07:36 AM   #5
Wombat2 is offline Wombat2  Australia
diyAudio Member
 
Wombat2's Avatar
 
Join Date: Nov 2003
Location: Brisbane
If identical batteries you can parallel no probs and double your amp/hours. Make sure (with hydrometer) that all cells are close in SG otherwise you will accelerate any breakdown.
  Reply With Quote
Old 23rd March 2006, 08:16 AM   #6
diyAudio Member
 
Join Date: Sep 2004
Location: Norway
Default 12V 100W SMPS ?

Hi Thunau

Quote:
The question is, is it safe to paralell the batteries with the switchers? If not, is there a circuit that would make the connection a sound one?
If batteries is of same type, status and brand you could easily parallel them for 12V double capacity.

But, parallel battery with SMPS, is not easy because of this:

Battery need at least 14-14,4 V when charging. When battery is full charged (by a suited battery-charger) the battery voltage will be approx. 13-13.2 V (=2.2V/cell). If connect battery to SMPS current could flow IN TO the SMPS and make some damage though the SMPS only have 12V outputs.

If you connect battery to SMPS when battery is <13.2V, say 12V, well your battery will newer be charged by the SMPS because it need at least 13.2 V to keep it maintenance charged.

Maybe you could trim outputs on SMPS to reach 13.2-13.8V then it could be an option. But the SMPS has no control on charging status for battery. Battery could be over charged if SMPS outputs reaches more than 13.8V. Also dont forget those batteries are not sealed (I guess) and can explode if a spark is made at one of the poles (thats why good chargers start a delayed charging, only AFTER battery had been safely connected to it) Those batteries do have oxygen and hydrogen inside the shell (= explosion risk to count on).

My suggestion is that you drive the amps only by your batteries OR only with your SMPS connected to a large capacitor bank for your purpose. Dont use your charger when you play your amps or else they could pic up high switching frequencies (only guessing) and burn your amps or loudspeakers though most modern chargers of today is built like a SMPS without the DC-filtering (=output normally consist only of pulsed DC at high frequency).

Just my thoughts

Regards
__________________
Regards
Flodstroem
  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
PC Power Supply Mod - Quick question for someone with an EE etc. calee4nyaboy Parts 7 31st December 2009 05:10 PM
Newbie question: How to battery power my cs4397 dac kit boidos Digital Line Level 2 31st May 2009 09:35 PM
Just a quick power supply capacitance question markiemrboo Chip Amps 137 14th February 2007 04:53 PM
Quick question - possible to build high-power current-source Class D amp? 454Casull Class D 2 24th November 2006 10:48 PM
Quick subwoofer/amp power question anglerz007 Car Audio 6 16th September 2006 03:29 AM


New To Site? Need Help?

All times are GMT. The time now is 07:36 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