Hi folks,
I'm getting ready to install a new Victron inverter and lithium batteries. I know there are several of you that eliminated the battery isolator and are using DC to DC chargers. I also have a DC to DC charger in my van so I am very familiar with them and what they do.
So, my question is, if I eliminate the isolator, what am I doing with the other wires coming into the isolator? There is a lead from the alternator and another one from the start battery.
I've been reading on other forums (SOB) that people just left the isolator in place and have had no issues. This kinda makes sense as the lead coming out of the isolator is a 2 gauge wire that is at least 25 feet long. At 12 - 14 volts, I can't see how that is going to stress the alternator all that much with the voltage and amperage drop in that distance to the batteries. But, I already have the DC to DC chargers and will probably install them anyway. I just don't know if my start batteries are going to get charged if I eliminate the isolator and what to do with the alternator input wire.
More questions to come on this I'm sure. I will post pictures once it's all done.
Kevin
Move the alternator wire in the center of the isolator and move it to the starter battery side. Or do like most of us did and put 2 terminals where the isolator was and attach the alternator wire and the start battery wires to one of the terminals and your b2b and coach batteries on the other.
I ditched the isolator 3 years ago. It's pretty easy to do. Just think about how you want to charge each battery bank, and run the cables as required. The post linked below shows my solution, which has worked just fine.
Delco Remy 28SI Alternator Installation (https://www.foreforums.com/index.php?topic=40778.msg405081#msg405081)
Check out this post answers 19-22
What is DUVAC? (https://www.foreforums.com/index.php?topic=33250.msg432531#msg432531)
Thanks for the answers guys. I'm pretty good with electricity, but when it comes to alternators and boost solenoids, that's where I don't have much experience.
So, I know that I will run a cable from the start battery to the DC-DC charger and it will charge the house batteries. Do I simply run the alternator cable directly to the start battery? What keeps the alternator from overcharging the start batteries?
This picture was posted by Tommy D. Is this what it should look like?
Also,
Another question before I forget. How does the generator charge the 12 volt batteries? Is it only producing 120v and the inverter is charging off of the 120v?
Thanks
Kevin
Kevin, your alternator will put any where between 13.6 to as high a 15+ volts depending on which alternator and how the regulator is set. 14.2 being about right. Start batteries are built differently than deep cycle batteries. Your Dc to Dc charger should be programmable to your house battery type for 3 stage charging, bulk, absorb, and float. As well as protect you alternator.
The voltage regulator in the alternator is what keeps the start batteries from over charging.,
There are 3 solenoids under the bed. What are the two that are together for? I assume the one that is by itself is the boost solenoid?
Thanks
Kevin
Should be unique numbers on each of the cables. Compare those numbers with your coach's wiring diagram.
If you follow the cable from one of the solenoids it will go to the pass side top of the motor that is the intake grid heaters for cold start. Have someone turn the boost switch on and off while you check which one clicks. IIRC one is the starter solenoid.