2nd Battery Hookup

Reply

  #1  
Old 05-03-06, 05:10 AM
Member
Thread Starter
Join Date: Dec 2002
Posts: 27
2nd Battery Hookup

I installed 2500 watt inverter in my 1997 ford explorer to power an oxygen consentrator. Everything works fine except that my alternator discharges at idle. I want to hook up a second battery; how do I accomplish this? What is an ISOLATOR? I have a 200 amp inline fuse already installed, do I need to instal another? where/how do I hook it into the alternator? Your help would be greatly appreciated. Stepdog 007.
 
Sponsored Links
  #2  
Old 05-03-06, 05:22 AM
the_tow_guy's Avatar
Group Moderator
Join Date: Feb 2001
Location: SW Fla USA
Posts: 11,515
Here's a pretty good article on the subject, dog:

http://www.bcae1.com/battiso.htm

See the section on Adding a second battery without using an isolator. An isolator does exactly what it says, isolates one battery from the other so that you can for instance run a bunch of accessories to the point of the battery being almost completely dead without discharging the other battery, i.e. you can still start the engine from the fully charged "isolated" battery.

I have two batteries on my wrecker; partner's truck has three [his hydraulics are via electric pump and mine is engine-driven so he needs the reserve power]. In our case it's simply a matter of having the batteries connected in parallel [NOT series!!!]. Ours don't look like the diagram in the link but instead are simply ties directly together from terminal to terminal [+ to + & - to - for the parallel circuit] You may want to investigate a higher output alternator if one is available.

If you Google "dual battery installation" you'll get tons of things to read.
 
  #3  
Old 05-03-06, 03:56 PM
Member
Join Date: Jan 2006
Location: Owen Sound Ontario Canada
Posts: 541
What is the current draw of this device (oxygen concentrator)
It sounds like the alternator can't keep up. To me it seems like higher engine Rpms are in order.
Take a look at this site and scroll down some to take a look at the graph of engine RPM verses power out of alternator.
http://www.uuhome.de/william.darden/carfaq5.htm

Now if we added another battery the the device has more power to run but the alternator will still read the discharge and try to make it up. The alternator cant do it now with one battery so it wont be able to charge 2 batteries at once.
The addition of an isolator will separate the outputs of the batteries making sure you have one to start the car with but it will not solve the discharging problem of the gauge.
Please forgive me if I am reading the question wrong.
I don't understand the 200 amp fuse??
Where is it connected to and why??
Please send back clarification because I am interested but confused
 
  #4  
Old 05-05-06, 04:30 PM
Member
Join Date: Apr 2005
Posts: 242
Originally Posted by frankiee
What is the current draw of this device (oxygen concentrator)
It sounds like the alternator can't keep up. To me it seems like higher engine Rpms are in order.
Take a look at this site and scroll down some to take a look at the graph of engine RPM verses power out of alternator.
http://www.uuhome.de/william.darden/carfaq5.htm

Now if we added another battery the the device has more power to run but the alternator will still read the discharge and try to make it up. The alternator cant do it now with one battery so it wont be able to charge 2 batteries at once.
The addition of an isolator will separate the outputs of the batteries making sure you have one to start the car with but it will not solve the discharging problem of the gauge.
Please forgive me if I am reading the question wrong.
I don't understand the 200 amp fuse??
Where is it connected to and why??
Please send back clarification because I am interested but confused
What size battery do you have? Sounds like you need a bigger alternater if yours is currently without problems. depending on your battery size you may be able to go with one larger battery and a alterantor upgrade. What size battery and what amp alternator do you have in it now?
 
  #5  
Old 05-05-06, 08:44 PM
LouBazooka's Avatar
Member
Join Date: Dec 2005
Posts: 553
installing another battery is not too much of a big deal as long as you have your wires right pos+ to pos + and neg - to neg-, from existing to new battery, make sure all terminals are covered,and make sure battery sits well and is secured to a plate or plastic box . Use proper wire gauge ( 0 I think ) and a fuse just in case.
as mentioned above you can also upgrade to a more powerful alt ( more amps output ) if you need more power at idling speed.
 
Reply

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


Thread Tools
Search this Thread
Display Modes
'