120 volt dc charging system - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 06-20-2008, 05:46 AM   #1
Registered Member
 
Join Date: May 2008
Posts: 140
Country: United States
120 volt dc charging system

if you were to use 120 volt dc motor, with 10 , 12 volt batteries in series, how could you charge them using 120 ac outlet?
__________________

mikehallbackhoe is offline   Reply With Quote
Old 06-20-2008, 06:12 AM   #2
Registered Member
 
GasSavers_RoadWarrior's Avatar
 
Join Date: Feb 2008
Posts: 1,652
Well you'd first have to rectify the AC into DC, then you'd probably find you had ~110V DC and you need more like 13.5-14.5V/cell to get any juice into the batts, so you could realistically charge only 8 cells in series.
__________________

__________________
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice
GasSavers_RoadWarrior is offline   Reply With Quote
Old 06-20-2008, 07:31 AM   #3
Registered Member
 
GasSavers_BEEF's Avatar
 
Join Date: Apr 2008
Posts: 1,831
wouldn't 120vac rectified be closer to 170 or 180vdc? 120 is the rms value thus when rectified will give you a constant peak. with that you could use a 180 volt system running your dc motor. but I think your range would be limited using car batteries.

my ac-dc theory may be rusty, been 10 years since college.
__________________
Be the change you wish to see in the world
--Mahatma Gandhi



GasSavers_BEEF is offline   Reply With Quote
Old 06-20-2008, 12:08 PM   #4
Registered Member
 
GasSavers_Randy's Avatar
 
Join Date: Apr 2006
Posts: 98
Country: United States
Yep, it's 170, but remember it still goes from 0 to 170 constantly. Without an inductor in there, the peak current would be too high and the average current too low.

A variac and rectifier would work, but a charger would pay for itself by charging the batteries right and making them last longer. If you want a cheaper system, drop the voltage.
GasSavers_Randy is offline   Reply With Quote
Old 06-20-2008, 12:17 PM   #5
Registered Member
 
GasSavers_BEEF's Avatar
 
Join Date: Apr 2008
Posts: 1,831
couldn't you use a capacitor bank like they do on DC motor drives to keep the voltage at 170 or near that? I understand that the current would be tremendous which could be a major problem.

may be better to charge them all together in parallel. possibly set up a switch matrix with contactors to change them from series to parallel for charging. those contactors could get expensive thoug. you could have a run state and a charge state for the system. maybe have the series (run) state using all normally closed contacts and the parallel (charge) state on all normally open contacts and use 120v coils on the contactors so that you have to plug it in to charge it. also have a set of normally opens that the charger has to go through just in case someone accidentally unplugged the system.

there is probably a much easier way and what I mentioned may be more complicated than I stated, not sure.
__________________
Be the change you wish to see in the world
--Mahatma Gandhi



GasSavers_BEEF is offline   Reply With Quote
Old 06-20-2008, 01:59 PM   #6
Registered Member
 
GasSavers_BEEF's Avatar
 
Join Date: Apr 2008
Posts: 1,831
this is something I threw together really quick so it may not be completely accurate but it may give you an idea of what I am talking about.

the contactors are pretty crude but remember that there are usually 4 sets of contacts on a contactor. also remember to take note of current carrying capacity of any contactors that you use. I think this will work but if you try it, it is at your own risk. I don't mind blowing up my own stuff but I am not going to be responsible for what someone else blows up.

also I am going on vacation and will not be posting for the next week so good luck
Attached Thumbnails
Click image for larger version

Name:	battery schematic.JPG
Views:	82
Size:	33.5 KB
ID:	1163  
__________________
Be the change you wish to see in the world
--Mahatma Gandhi



GasSavers_BEEF is offline   Reply With Quote
Old 07-01-2008, 10:23 PM   #7
Registered Member
 
GasSavers_JoeBob's Avatar
 
Join Date: Oct 2007
Posts: 698
Country: United States
A friend of mine got around this by using a charger which runs on 240 volts...
__________________

__________________
"We are forces of chaos and anarchy. Everything they say we are we are, and we are very proud of ourselves!" -- Jefferson Airplane

Dick Naugle says: 1. Prepare food fresh. 2. Serve customers fast. 3. Keep place clean.



GasSavers_JoeBob is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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
Fuelly Android App - eehokie Fuelly Web Support and Community News 2 07-14-2010 09:59 PM
Not getting impressive fuel economy with the Civic DUBPL8 General Maintenance and Repair 31 08-25-2007 05:12 PM
1992 Honda Civic VX - $2,499 NJ Sigifrith For Sale 4 08-20-2007 05:57 AM
New Member sl2w0 Introduce Yourself - New member Welcome 6 06-05-2007 11:17 PM
Loremo Sludgy General Fuel Topics 7 10-29-2006 10:16 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 03:04 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.