Going to Lithium

[jsay]

First question: Where to mount the Dc-Dc charger?
2018 Sunseeker MBS
It looks like there is plenty of room in the engine bay where the generated heat can dissipate.
I have the larger 220Amp alternator so I shouldn't have issues there.
I can't see the face of my converter to see if it has a LI switch. How do I know if it will put out the required 14.6v from my shore power or generator?
Thanks!

 

[TacomaJoe]

DC-DC should be close to the battery because it will compensate for voltage drop on the input side. If you have voltage drop on the output side because of cable length, the output voltage could be 14.6V but only 14.6V at the battery.

If your converter can get the battery close to full, the DC-DC can top it off.

 

[jsay]

TacomaJoe, Thanks! I assume that the DC-DC should be close to the LI house batteries, not the coach batteries?

 

[mmartin_tdc]

TacomaJoe, Thanks! I assume that the DC-DC should be close to the LI house batteries, not the coach batteries?

correct

 

[Rich.M]

I placed mine under the passenger seat

 

[TomAR]

Progressive Dynamics has (had?) a lithium module for your charger/converter. Pretty simple to swap it out.
Why make it more complicated with a DC/DC charger (unless you're doing solar or adding an inverter)?
You'll need a LiBIM as well.
Victron BVM-712 is very worthwhile, too.

 

[Reverse_snowbird]

Progressive Dynamics has (had?) a lithium module for your charger/converter. Pretty simple to swap it out.
Why make it more complicated with a DC/DC charger (unless you're doing solar or adding an inverter)?
You'll need a LiBIM as well.
Victron BVM-712 is very worthwhile, too.

They need a dc-dc charger to protect the alternator of his motorhome. While driving, the engine charges the house batteries.

 

[Aussieguy]

BUT............ he has the 220 amp heavy duty
any one had problems with that alternator?

it may be built better to withstand the extra load/temperature
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OR simply have a switch so you can turn on/off the alternator charging when you are:
in slow traffic
or real hot days
or only turn it on to help the solar, near the end of your driving day when battery won't be heavily depleted and pulling less amps.

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If you can add solar.. 400-600w you may not need the dc-dc or alternator charging of the house
AND...... it will charge while you are NOT driving
also look at combination roof + portable panel

 

[jsay]

Progressive Dynamics has (had?) a lithium module for your charger/converter. Pretty simple to swap it out.
Why make it more complicated with a DC/DC charger (unless you're doing solar or adding an inverter)?
You'll need a LiBIM as well.
Victron BVM-712 is very worthwhile, too.

TomAR,
Thanks! I found the Prog Dynamics upgrade for LI.
I will be adding solar & an inverter soon.
I do have the Victron 712 on the way also.

 

[TomAR]

Don't forget that Li-BIM!
Needed so you charge batteries while driving. I made up some new wires for a neater installation, but maintained same color-coding. It's so reassuring to arrive at the campsite with batteries fully charged.

 

[jsay]

Damn i feel slow...
Do I need to remove the original Coach to House battery connection, then add the DC-DC charger. If so how do I determine which cable is from Coach to House?
Thanks!

 

[TomAR]

Mine was a fairly simple setup. I was just upgrading two 100 Ah batteries from LA to Lithium; no solar, no inverter. Needed batteries; upgraded my charger/converter; upgraded my BIM to LiBIM. Added heating pads to the batteries. Added Victron BVM w/shunt to give me a SOC indicator.
I suggest that you prepare a detailed diagram of all the key elements and their connections for your Lithium upgrade. It's too complicated to just cover bits in forum posts.
PS - With just two 100 Ah batteries, it's hardly worthwhile to add an inverter. Have you mapped your projected electrical loads?

 

[Aussieguy]

Damn i feel slow...
Do I need to remove the original Coach to House battery connection, then add the DC-DC charger. If so how do I determine which cable is from Coach to House?
Thanks!

If you camp for many days in one spot ... Alternator Charging using a BIM or Dc-Dc is not the greatest option.
As it only works while you are driving.

Decide what power you use
AND what camping style you do
AND how you can recharge the batteries

Shorepower each Day Disconnect standard BIM
just use shore power

Generator... upgrade the battery charger Converter to work better with Lifepo4... Less generator time

Solar .... you can just Disconnect the standard BIM if you got enough solar

DC-DC or Li BIM ... only if you drive enough to warrant getting the equipment and any wiring you may need.
DC-DC is a better option if you only drive around 4 hours or less

You can get the batteries and UPGRADE stuff as you decide you need it
as TomAR said... just get batteries first.... If you not a power hog you can last a weekend or more. Then when you get home or to a campground charge them up.

 

[RVrover]

LiBIM Does it

I second TomAR's comments. Here's my entire solar setup: Here and here. Hopfully it adds some value to your thinking.

The BIM charges my chassis battery automatically whenever the voltage drop there by 10% making sure it is always ready to go when I am. I can also use the emergency start button under the driver's seat to trigger the BIM to jump the battery, which I never needed since I had this BIM.

 

[jsay]

LI done! New knowledge.

Thanks to all that helped. I've got my new batteries, charges, monitors and controllers installed And working. Once I wrapped my head around how it all works it was fairly easy. Finding where to run wires ans seal everything took a bit of time. Now to see how they work.
Thanks!

 

[Aussieguy]

wooo hoooo party time in Kauia

 

[TomAR]

So, show us pictures!

 

[jsay]

I will get photos out soon.

It seems that I need to disconnect my original Chassis battery connection so that it runs through the DC-DC. How/where can I do that? From the Battery Isolator Relay?

 

[jsay]

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