Inverters, House/Chassis Isolation, and other 12v technology

[waterskier_1]

15 hours ago, JDCrow said:

Yeah the DC/DC just takes alternator charge and outputs to the house lithium. 
 

I wanted to get away from the bird, and boost. I figured it was “simpler” this way. Can always us jumper cables. 
 

 

Ideally, I should never have to run the genset while driving. My AC pump is froze, it was hot so I tried it. I’ll Fix the AC pump, and the inverter can power the micro to Nuke something while driving or keep us from firing up the genset. 
 

For me it just learning. I don’t have the mindset as some for this, it’s just cool to kinda have a slight grasp of the concepts. 
 

One other note. I’m not an electrician as you may have guessed. But on the Multiplus 2 there is a small outlet for a 4 amp trickle charge to goto the chassis battery. With the inverter off, I went to hook run a wire to that, and got a spark. Now, I’m always under the impression that I shouldn’t be grounding out running the positive to positive? 

I think you may have a defective MultiPlus.  You should have 12-14 volts (I can't find anything in the tech materials to say what the charge voltage is, nor if it's "smart" or not.  Since it's designated as "starting battery" I am assuming it's charging the same as an alternator, which is fixed 14.2 - 14.4 volts.  In any case, it should not spark, unless the battery you are connecting it to is severely discharged.  I can't see how the DC-DC charger or the MultiPlus can be affecting the ECM side unless either the MultiPlus is defective, or you have bad batteries/connections (including grounds).  I think this is something that isn't likely going to be solved without actually taking measurements.  But, it could be a bad configuration parameter in the setting up of either the DC-DC Charger parameters or the MultiPlus.  How did you configure the MultiPlus?   Did you use VEConfig and a computer?  

[JDCrow]

43 minutes ago, waterskier_1 said:

I think you may have a defective MultiPlus.  You should have 12-14 volts (I can't find anything in the tech materials to say what the charge voltage is, nor if it's "smart" or not.  Since it's designated as "starting battery" I am assuming it's charging the same as an alternator, which is fixed 14.2 - 14.4 volts.  In any case, it should not spark, unless the battery you are connecting it to is severely discharged.  I can't see how the DC-DC charger or the MultiPlus can be affecting the ECM side unless either the MultiPlus is defective, or you have bad batteries/connections (including grounds).  I think this is something that isn't likely going to be solved without actually taking measurements.  But, it could be a bad configuration parameter in the setting up of either the DC-DC Charger parameters or the MultiPlus.  How did you configure the MultiPlus?   Did you use VEConfig and a computer?  

I did use VEConfig. The local shop I bought the Multiplus offers free programing from a Victron master tech. I should just run it down there and let them look it over. 
 

Thanks for your insight and help

 

[Bjohnsonmn]

1 hour ago, waterskier_1 said:

Be aware that the Li-BIM is a backyard shade tree fix.  It only address the alternator overloading problem.  It doesn't have any charge profile (algorithm).  It's either full 14.4 volts from the alternator for 15 minutes, then off for 35 minutes, then back on at 14.4 volts for another 15 minutes and then back off for 35 minutes, over and over as you drive down the highway.  You are either charging your LiFePO4 at 14.4 or 0.0.  Neither is ideal, for a day's drive time.  That is why informed are going with DC-DC Chargers, which both limit the current draw from the alternator, but also have a smart charger built in to properly charge/maintain LiFePO4 batteries.

 -Rick N. 

It looks like I am going to be going with a Victron Cyrix (spelling?) That is made for Li-Acid setups like this.

[waterskier_1]

1 hour ago, JDCrow said:

I did use VEConfig. The local shop I bought the Multiplus offers free programing from a Victron master tech. I should just run it down there and let them look it over. 
 

Thanks for your insight and help

 

Yes, I'd do that.  I'm not sure what a Master Tech is, but that sounds like he might be helpful.  I'm a Victron Professional, but that doesn't mean a lot.

[JDCrow]

28 minutes ago, waterskier_1 said:

Yes, I'd do that.  I'm not sure what a Master Tech is, but that sounds like he might be helpful.  I'm a Victron Professional, but that doesn't mean a lot.

In use master tech as anyone smarter than Me. He’s certified 

[waterskier_1]

1 hour ago, Bjohnsonmn said:

It looks like I am going to be going with a Victron Cyrix (spelling?) That is made for Li-Acid setups like this.

Are you sure you understand how the Cyrix Li-ct works?  I had to study the spec sheets and then go to the Victron forums to fully understand how this is different from a BIRD in our coaches (or Big Boy if yours is an older coach).  All this is is a BIRD system with external control.  The non-Lithium Cyrix ct is just a BIRD.  The difference is that the Li-ct allows for a BMS (Battery Management System) control input.  That is, when your BMS show the battery is too hot or charging too fast or otherwise not in specific limits, it can send a signal to the Li-ct to disengage.  You MUST have a compatible BMS for this to work. 

I really don't think this is what you want.  If you don't have the compatible BMS, you might as well get the Cyrix ct, or a Blue Sea SI-ARC which is likely much cheaper.  BUT none of these will protect your alternator from excessive current draw (assuming you do not have a compatible BMS) nor will any of the regulate the charging profile.  

I think the Victron Orion DC-DC Charge is what you really will want.  Look the spec's over and ask questions if you don't understand.

  -Rick N.

[windsorbill06]

rick,

I'm seriously looking into replacing my old Magnum that is original MSW and does NOT support lithium.   Looking at the Victron Multiplus2 as others have done.  

Studying the Magnum wiring and the MP2 wiring, it's definitely not Plug and Play.  Quite a bit of re-wiring.

Question on programing the MP2.   Does getting the CerboGX and the color display help in anyway for programing the MP2, or do you still need  VEconfigure and a computer?