Problem installing lithium batteries

[Jon Wells]

I'm working on switching out my house batteries with lithium.  [2006 Monterey]  I thought I had things working okay.  We went into my brother's house for dinner, and when we came back, the power was off.  We have a Magnum inverter/charger, and the ME-RC remote was showing a fault and the display saying dead battery  3 volts.  The batteries' Bluetooth app were showing the batteries were fine.  I tried resetting the inverter, and it would not work.  On the old batteries (2 pairs of 6 volt batteries), I remember removing two main cables (black/negative); one went to one of the 6 volt pairs, and the other cable went to other pair.  There was also a jumper between them.  I thought it was strange.  My wiring diagram does not show to negative cables.  I turned everything off (shore power, etc.) and then started to pull the negative cables.  I was surprised when one of the cables produce a good spark.  What I find totally strange is that the loose black cable is showing +6 volts ()  I cannot figure out where that is coming from.  Any ideas?

I may have to put the old batteries back.

[Joel Ashley]

I eventually scrapped my lithium ideas when it just got too complicated, never mind expensive.  There were some respected opinions that said adding them would be no issue, but I later ran into pushback on that idea as I zeroed in on installation requirements.  I think there was need for a more modern Magnum remote among other things, and perhaps a newer solar controller.  I opted for well-reviewed and researched AGMs instead.

You should’ve taken a photo of and/or drawn a diagram of your original wire routing, but if not find attached what it should be, and a pic of my new AGMs.

Joel

[Bill Lampkin]

The BMS (battery management system) in your Li batteries SHOULD have protected them from mis wiring. YOur old batts were 4x6v ea which means they were wired in series/ parallel. Your new lithium, if each is 6v will be wired the same, but I suspect you have (4) x 12
v li batteries? is that right? 12v batteries are wired in parallel (+ to + and - to-). You ask about two negative cables, my coach (4x 6v) has two negative cables, this is done to minimize voltage drop to the inverter. If you trace your cables, the two negatives will join at a big battery terminal near the inverter. As far as connecting your li in parallel, check with who you bought them from, as they might limit the number of batteries connected that way (parallel). If none of this makes any sense, find an RV electrician who knows his stuff. And, you are right to go to lithium, but with that big of an investment, you better get some real help to install them correctly.

[Jon Wells]

I was going from 4 - 6 volt batteries to 2 - 12 batteries.  I attached a Word xdoc file that shows what I went through which is within the size limits of this forum's platform.  It occurred to me that the two negative cables may have been for a better ground connection.  I originally thought that the jumper between the two negative terminals was there for the temperature sending unit.  I was going to add the jumper back in, but I halted this when I got the sparks from the cable I had disconnected and discovered that there was +6volts at the end of the cable.  I did put the old batteries back in, and things are working again.  I'm sure wondering why I had the +6volts reading from the cable I disconnected. 

My ME-RC is version 2.8, which is connected to MSH3012M inverter/charger.  According to LifeBlue, I needed to set things up as -->

1. Setup 02 LowBattCutOut: LBCO = 12.0 Volts**
2. Setup 04 Battery Type: CC/CV
    Status Max Amps = 200*
    Status Chg Volts = 14.2V to 14.6V** [I set it to 14.2V]
    Status EndChg = Time
    Status DoneTime = 0.2Hr**
    Status Max Time = 12.0Hr
    Status ReCharge = 13.3***

[Jon Wells]

As it turned out, I was dealing with a problem with my shore power plug.  I remember when I plugged in awhile ago that it looked like the wire had pulled out just a bit.  Well it was pulled out enough to fry my plug.  Fortunately I was able to pick up a replacement plug.  This afternoon I re-installed the LifeBlue batteries and set the remote up per the instructions from LifeBlue.  So far it has been working well.

Thank you everyone. 
Jon

[Don McKnight]

Jon i have a 2006 Monterey as well and looking to make the switch. How did you deal with the alternator to prevent it from burning up while driving?

[Fred Brooks]

   Don,
Alternators do not play well with Lithium batteries. Most installations do not allow the alternator to charge the lithium batteries. They use a "DC to DC" charger to interface between the chassis batteries and the lithium house batteries. Victron makes a 50 amp version. Coach assist has a electrical diagram of your 06 Monterey. Fred