Float charger? Cut off at 13.5v rest until 12.5v before switch on? - Page 5 - 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 4th August 2012, 03:13 PM   #41
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by Elvee View Post
The delta between voltages is normally set by D3/D4/D7: by substituting smaller or larger devices or adding one, you can adjust the hysteresis. Anyway, if you have achieved what you aimed at, that's the only thing that counts. Scott's proposition looks sensible, if you are prepared to jettison your relay
Thank you sir! Your overcharge protection circuit gave my old misbehaving noisy ("grrrr") hot converter charger some much needed rest. The relay is switching an additional reed relay that is switching a large AC relay (doesn't run from battery power) that is keeping a large AC charger disconnected when it isn't needed (rather than its previous nonstop ccs behavior). With only 22ma draw during float, it can keep the AC charger asleep for days. With that plus a fridge sensor, battery sensor and radio memory, the time is about 2 days. That was the target.

But I also have a solar panel, since the plan is to keep the AC charger asleep by using solar charge just a fraction higher than the AC charger. It is a 30w (max rated) panel. So kicking myself for not choosing a 5w panel that could not overcharge a large battery or a 10w panel easily managed by buck boost card (capacity of the buck boost is higher than the max current of the solar panel), but no, I got a 30w panel that is much harder to manage. . .
Quote:
Originally Posted by scott wurcer View Post
Daniel, I got 10+ years (still going) on a bank of FLA batteries even through New England winters with this float charger. I think holding the voltage right up against the self discharge is the recommended way. This circuit never draws more than the self discharge current no matter what the source. The source of float and bulk charge are isolated to allow maximum versatility.
Thanks. What component values do you recommend? My battery "idles" at 12.77, easily charges at up to 13.5, begrudgingly goes to 13.8. . . and has accelerated wear when out of this range. It also has accelerated wear when kept to one steady voltage charge but that is not a concern with the solar panel that rests every night. Anyway, I'd like to try your circuit for the solar panel, so what component values to start with, and how to trim?
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  Reply With Quote
Old 4th August 2012, 04:42 PM   #42
diyAudio Member
 
sakellogg's Avatar
 
Join Date: Nov 2008
Location: dixon ill
Default chargers

i didnt read all of the posts, and if i missed somthing sorry.

where i work we use huge batteries, for backup power at railroad crossings and other sites to allow trains to run even in outage situations.

the chargers we use are made by 2 or 3 diffrent companys.
they are self regulating (float voltages set by users) and will monitor temp.

i can say from experiance, if you take care of the batteries they will last a long time.

look up craig railchargers, and you can see what i am talking about.

i have saved several that have gone "grounded" that no longer are useable on the railroad due to FRA regulations.

send me a pm and ill tell u more.
__________________
I'm not crazy, my mother had me tested
  Reply With Quote
Old 10th August 2012, 09:20 PM   #43
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by Elvee View Post
The delta between voltages is normally set by D3/D4/D7: by substituting smaller or larger devices or adding one, you can adjust the hysteresis. Anyway, if you have achieved what you aimed at, that's the only thing that counts. Scott's proposition looks sensible, if you are prepared to jettison your relay
Ah, well, actually, the circuit failed. I suspect the cause of failure was the RV half wave converter/charger output. The battery didn't quite smooth that out as expected. The relay outputted first 6v and then steadily climbed up to 13.6v, plus it was making a lot of chatter and squealing noises. This didn't happen on ordinary DC, so perhaps it could work for solar. Anyway, with the AC charger, the battery ended up not charged at all, and the relay broke from all the chattering. I've no idea where to go from here but it seems that I should try something different for the high amperage AC charger. Help? I need some ideas.
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  Reply With Quote
Old 10th August 2012, 09:37 PM   #44
diyAudio Member
 
keantoken's Avatar
 
Join Date: Aug 2006
Location: Texas
Blog Entries: 2
MOSFET relay? Could a single MOSFET work?
  Reply With Quote
Old 10th August 2012, 10:34 PM   #45
diyAudio Member
 
Join Date: Nov 2008
Location: Victoria,TX
Blog Entries: 1
The problem i is that single diode will give you a pulsating DC volts. You need to smooth it out. Try a diode and capacitor to power the relay. Pulsating DC will make your relay chattering.
  Reply With Quote
Old 10th August 2012, 10:37 PM   #46
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
Look up Ctek chargers, cheaper to buy one of those (and smaller) than make your own.
__________________
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more.
  Reply With Quote
Old 10th August 2012, 10:38 PM   #47
diyAudio Member
 
Join Date: Nov 2008
Location: Victoria,TX
Blog Entries: 1
Another solution is to add a large capacitor to the output of the converter that will fix the problem also.
  Reply With Quote
Old 11th August 2012, 08:17 AM   #48
Elvee is offline Elvee  Belgium
diyAudio Member
 
Elvee's Avatar
 
Join Date: Sep 2006
Quote:
Originally Posted by tauro0221 View Post
Another solution is to add a large capacitor to the output of the converter that will fix the problem also.
Yes, that is the simplest option if you want to keep the circuit as it is.

Try a 10,000µF for example.

Any residual ripple smaller than the hysteresis will apparently reduce it.
__________________
. .Circlophone your life !!!! . .
♫♪ My little cheap Circlophone© ♫♪
  Reply With Quote
Old 11th August 2012, 07:57 PM   #49
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by tauro0221 View Post
Another solution is to add a large capacitor to the output of the converter that will fix the problem also.
That doesn't work well--it makes 18vdc, which is not compatible.
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  Reply With Quote
Old 11th August 2012, 08:31 PM   #50
diyAudio Member
 
Join Date: Nov 2008
Location: Victoria,TX
Blog Entries: 1
That is right 13.5 X1.4 = 18.4 volts. Then use a diode to isolate the dc pulsating with a capacitor and a dropping resistor to feed the relay.
  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
5v to 2.5v for 2a3 filament gasser-dude Tubes / Valves 7 13th February 2010 10:18 AM
12-14.4v to regulated 12v & 5v agithegreat Power Supplies 16 2nd January 2010 03:29 AM
Good 13.5V up to 5A PSU prinzinio Power Supplies 0 29th May 2009 03:27 PM
Switchmode power supplies - 13.5V/40W - Ideal for T-AMP Fin Group Buys 9 4th June 2008 07:43 PM
Can you make 0-5V DC out of 2.5-0-2.5V AC Ralph Tubes / Valves 17 23rd September 2003 04:20 PM


New To Site? Need Help?

All times are GMT. The time now is 07:44 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