Charging batteries with a variable power supply - 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 10th April 2007, 06:34 AM   #1
diyAudio Member
 
jacquesl's Avatar
 
Join Date: Feb 2005
Location: Lego Land
Post Charging batteries with a variable power supply

How to charge a normal lead acid car battery and an Absorbent glass mat 7ah battery

I have a diode built into my power supply

How can I build a charger that will maintain the battery for then needed, it’s like a UPS type
Will it work if I use my 1.5A variable power supply and set the output to exactly 13.80 volt DC, will that charge my battery to 13.80 and maintain it without overcharging for a couple of years and without making gas builds ups

In my test it’s a discharged battery and the power supply is set to 13,80V DC and if I connect the wires the voltage drop down to 13.40v and it charge at a rate of 0.20A, but why not 1A or 1,5A ?
  Reply With Quote
Old 10th April 2007, 12:01 PM   #2
leto is offline leto  France
diyAudio Member
 
Join Date: Apr 2007
Default Re: Charging batteries with a variable power supply

Quote:
Originally posted by jacquesl
it charge at a rate of 0.20A, but why not 1A or 1,5A ?
Mainly because of battery overheating risks... I think !
  Reply With Quote
Old 13th April 2007, 06:23 PM   #3
diyAudio Member
 
Join Date: Jun 2005
Location: Sunderland
the best way to charge a SLA or Vrsla type battery is using a controlled impedance charger.
sounds bad but in practice its a 317 regulator from nat semi or sgs. sgs has an app in the l317 data sheet on this, circuit is simple placing a .22 R resistor in serise with the output, with feed back poost resistor, output impedance is them RS (0.22)*Rf/Ri so real resistor is .22 R, apparent is much higher. see http://www.st.com/stonline/products/...2154/lm317.pdf
figure 12
works for all batteries of the sla type I have tried, prevents boiling the battery.
__________________
Anthony C Smith MAES MinstSCE
-I think rain is wet so who am I to Judge-
  Reply With Quote
Old 13th April 2007, 06:36 PM   #4
diyAudio Member
 
jacquesl's Avatar
 
Join Date: Feb 2005
Location: Lego Land
Thanks man, it looks nice, I’ll try it out, I have some LM317 regulators, and in my datasheet from “Fairchild semiconductors” they don’t give some sweet examples from the LM317.
  Reply With Quote
Old 13th March 2013, 07:52 PM   #5
diyAudio Member
 
Join Date: Mar 2012
Location: ISANDO GAUTENG
Default Charger

Quote:
Originally Posted by jacquesl View Post
Thanks man, it looks nice, I’ll try it out, I have some LM317 regulators, and in my datasheet from “Fairchild semiconductors” they don’t give some sweet examples from the LM317.
I know that this is a thread of long ago but did you solve the low current output of your P.S.U.? I built a lot of chargers of this kind for lift trucks and all they were was a stabilized PSU with a current limiter to protect the poor transformer if the customer start to use the charger to drive the truck when the batteries were depleted
Your PSU "see" the battery as just another load.Do you have a 723 type I.C. ? Scrap it that is the worst I.C. on the market!!!!!!!!!! I eventually replaced it with a discrete circuit but I used small power transistors where a small transistor was specified (3amp vs.100mA) The extra expense of those power transistors paid for itself in reliability .
  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
Charging Lithium ion batteries Diy_Ambitious Power Supplies 11 28th January 2013 06:42 PM
Charging batteries with a variable power supply jacquesl Power Supplies 4 14th April 2007 06:25 PM
smart way to charging batteries. hacknet Solid State 26 28th November 2003 05:43 AM


New To Site? Need Help?

All times are GMT. The time now is 04:19 PM.


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