Originally posted by hoss+Aug 6 2004, 07:24 PM--><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (hoss @ Aug 6 2004, 07:24 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-SHOZ123@Aug 6 2004, 01:28 PM
Another thing about adding a second battery is how are you going to charge it? The voltage regulator in the alternator will be looking at the total system voltage which should be the same on each battery. But each battery unless identical in both environmental conditions and battery type, will be subjected to the same current flow. Even identical paired and put in service at the same time batteries with one in the trunk and one in the engine compartment is going to cause problems. The one in the engine compartment is subject to a lot more heat which will affect the performance of the battery as compared to the battery in the trunk.
You really need a second battery charging circuit device to make a two battery system work well. In all you are spending a lot of money, adding a lot more weight to get what one good battery and good cables can give you.
you dont need any extra equipment... the alt will charge them both the same, the voltage regulator on the alt regulates what it puts out, not what it charges the battery to. batteries come with a pre-determined charge, whether it be 8v, 12, 16, or 18v, and they will not charge to a higher level. the voltage regulator just looks at what is coming out of the alternator and if it sees that more volatage is coming out, it backs it down to the accepted rate.
the only thing that you might consider when running a second battery is a battery isolator. this will prevent parasitic loss between the batteries. when the batteries sit with nothing charging them they will constantly try to match each others voltage by lowering themselves. however, they are usually off by a very slight amount and they will continue to drain themselves until they are drawn to a voltage where they no longer become useful to start the car. however, you really only need an isolator if you are going to let your car sit for an extended period of time, and in which case you can simply undo one of the batteries from the system. [/b][/quote]
hoss...please dont take this personally, and i know you and paul are going at it, but the statement you just made is so wrong i cant even tell you.
Paul is a very informed individual with alot of research behind his answers. Dont be so easy to discreadit him, or me. The statement you made just put alot of your creadibility out the window.
Im not gonna get into how the voltage regulator works, but it is actually a current regulator more than anything.
It does measue the charge of the battery, thats why theres and EXTERNAL sense lead, otherwise, the alt would not need one.
It lowers the CURRENT supplied to the battery as the charge rises. Otherwise i could charge the battery to 16-17 volts and boil it over. This current limitation sets the voltage to a certian point, sucha as 14.4, and thus is misnomered as a vltage regulator. (So it does both).
Brad