Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 06, 2025 ...

The Lead is Dead....New Lithium Install...

March 07, 2024, 08:52:36 pm

In a previous post regarding coach DC power, I noted I was about to pull the lead and install lithium batteries and an "up to date", NEC 551 compliant DC power distribution system.  Well sans the installation of the Sterling DC to DC charger, the project is done.

First I will say (flack jacket on), the DC system (house panel) and associated wiring (with plumbing mixed in) mess gave me "pause" regarding FT quality control in 2002...or even rational thought.  While functional (and I use that term very loosely), virtually every rule related to primary power distribution was broken..... (Can you say "I wish I had a Wanderlodge?)...  but I digress.

Project entailed the installation of a custom built power power distribution panel in a coach with no space (a 36 foot U320).  Had to get creative so I looked to the heavens (or at least under the floor) and then "there was space". 

Hardware details are as follows:

4 Each LiTime 230 AH lithium iron phosphate batteries (looked long and hard at all the battery options, including Lithionics).  LiTime was most cooperative with answering every question promptly and even sent me pictures of the internals....  Their quality rivaled much more expensive batteries as well as using automotive A grade cells from either EVE or CATL.

Victron 1500 amp Buss Bar with modular Mega Fuse holders for distribution.  Didn't like their Lynx system as too much space for too little density...  over 12 inches for only 4 fuse positions?

Victron 1000 amp Smart Shunt.  Didn't need the 1000 amps but the multi-connection terminal blocks on the shunt eliminated the need for a secondary negative buss bar.....can you say "save space?".

Blue Sea 600 amp ANL fuse holder for main aggregated battery fuse.

Blue Sea Terminal Fuse holders for each battery.

Hand made, copper buss connections for the Pos and Neg battery buss connection to main fuse and shunt...and I can say lots of fun twisting 3/16 inch copper bar and getting a "square".90 degree turn.

Many...MANY crimp connectors and way too much 4/0 cable....  I think copper is worth more than gold these days.

600 amp master disconnect switch

300 amp inverter DC disconnect switch

Sterling Power 70 amp DC-DC charge controller w/reverse charging.

Victron 200 amp FET Battery Isolator..  Worth every penny, near zero loss even at full load.

Kept the existing Xantrex SW3012 for the time being.  Good, brute force, hard to kill inverter/charger.  Would like a Victron Multi-Plus II 120 X 2 but until I can figure out how to run two 6 AWG/4 conductor cables from the A.C. distribution under the bed to the inverter in the main bay, that will remain a "wish".

and a "Homer Bucket" full of odds and ends with many trips to the store no matter how hard I planned and documented...  kind of like home plumbing projects.

Anyway I think the pictures will tell the tail.  While a couple issues (like an unmovable Aquahot line mixed in with the electrical) thwarted my anal-perfection thinking, I think the end result will work well as planned.  Next will be the solar....

Questions, comments...yada, yada....  Standing by!

Bob

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Re: The Lead is Dead....New Lithium Install...

Reply #1 – March 08, 2024, 10:02:03 am

Nice install, playing with 4/0 is a challenge

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Re: The Lead is Dead....New Lithium Install...

Reply #2 – March 08, 2024, 11:23:40 am

Not a project for those less talented than you, but an excellent write-up accompanied by clear photo documentation.

These are the type of posts that make this Forum great!

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Re: The Lead is Dead....New Lithium Install...

Reply #3 – March 08, 2024, 11:26:51 am

Very nice install. Would look better in my coach! Think I have system envy

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Re: The Lead is Dead....New Lithium Install...

Reply #4 – March 08, 2024, 12:19:18 pm

So as nice as the 4 O cabling is, is it really needed. Largest load wouldnt require it. It's not like you are starting the coach with them. Just curious.

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Re: The Lead is Dead....New Lithium Install...

Reply #5 – March 08, 2024, 02:52:03 pm

First, thanks for the comments.  As to the 4/0 cabling, my EE/ telecom power engineering hat on says error to the extreme.  In hind sight, 2/0 from the batteries would have been sufficient. 

The need for consistent balance of load with lithiums can be problematic.  High loads, even for short periods can cause battery and thus cell imbalance and in an RV installation where breaking the string apart to manage a single battery is impractical.  So, everything you can do to ensure no restrictions to draw down is in your  favor.  Even variance in cable lengths can  contribute to imbalance creep.  You will note not only is each battery fed to the common busses, but there are identical length jumpers between each battery....  all in an effort to ensure battery/cell balance.

BMS systems are good at keeping a single battery cell pack in balance, but without external balancers, the batteries themselves can creep over time if the current flow conditions are not managed.

Anyway, happy for observations and comments.  In any case, I hope this can be a learning ..or maybe just informational experience for others.  Is it perfect, no.  Is if fully safe, mantainable and functional for my mission, yes.

I have some additional pix I will post with some other thought and execution comments.  This is my third personal coach I have done major power upgrades on as well as working through the process with others.  Every one has been an adventure with differing  conditions and obstacles...and the learning. continues.

As they say, keep those cards and letters coming!

Bob

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Re: The Lead is Dead....New Lithium Install...

Reply #6 – March 08, 2024, 06:14:42 pm

  Holy Batbattery Batman
First time in my life I've been jealous of something battery powered. I gotta get me some of those   
  I hadn't heard about the length of cables causing an in balance.
But I have noticed that on a couple of smaller batteries I have dissected the BMS to cell wires are always the same. Guess now I know why. Thanks for your time, great post.

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