Off-Grid Upgrade Minimal Design – Victron Multiplus-II and 600AH Epoch LiFePO4

[John Dorrer]

JD, This is great thread for those with older trailers. I'm always amazed by the depth of knowledge by a number of members.

 

Hoping our 2022 carries us for years to come, without having to do anything major. Anything electric is over my head🙃

 

Thanks for sharing all your mods.

 

JD

[jd1923]

Who's ready for ne LiFePO4? Got an email on this today, 15% OFF Epoch!
https://www.epochbatteries.com/collections/rv-van-camper-lithium-batteries

[Teaney Hull 292]

On 2/4/2025 at 11:21 PM, johnwen said:

Thanks for this awesome post with pictures, JD!  Although my installation is a little different it was very helpful, to me, to see that these batteries indeed fit into the battery tray.  And thanks much to Scuba RX ,here at the "Q", with helping me  remove the wiring rat nest in the battery cave....+ and - bus bars were so easy to install!  I now have only 2 wires inside my battery cave!  Pictures later after my DC to DC charger installation.......happy camper again!

John

Look forward to the pics

[jd1923]

Epoch batteries were on sale again for Black Friday and I'd been thinking about adding another one. Our 600 Ah system has been great, all we needed for the last year+ (MP2 Inverter always ON with many AC appliances running). Since we're adding an efficient A/C this will allow us to run air long enough on those hot afternoons! We're tired of having to be in a campground on hot days!

I was back and forth on spending the money, so I asked Chris and, in a heartbeat, she said "Do it!" I've finally let go of the RV owner's syndrome known as SOC-Worry! I'm now just fine when it gets under 50%, but it worries Chris some. Hopefully, NOT anymore!

Two Epoch 300 Essentials fit nicely in the OEM battery tray. I knew adding #3 meant a custom installation. First to-do was to remove the battery tray. Would you believe that alone weighs 30 LBS! Then cleaned up the bay and filled the mounting holes. I had scrap rubber from the TSC stall mats I used to line my truck bed (the wheel-well cutouts) and after trimming them a couple inches shorter they fit perfectly!

I kept looking at that big bolt in the center of the bay, and wondering why OTT would have done that!? Our friend @mountainoliver gave me a heads up on that and I got under the streetside bed and found the support beam the other end of the bolt (pic2). I started thinking I could somehow secure 3 batteries using that bolt. After sleeping on it, I thought of replacing the bolt with a 1/2" eyelet bolt and use it to strap and lock the batteries down!

[jd1923]

I found this great supplier of Made-in-USA cam-buckle straps and tie-downs:
https://www.amazon.com/stores/PowerTyeMFG/page/66AA148A-1600-4E0D-A1AA-AEA3A1050247?lp_asin=B017BYSJ7I/

I purchased this cable lock to secure the batteries: https://www.amazon.com/dp/B00006407M/?th=1

I turned the eyelet bolt on an angle so that the cable lock and strap would fit nicely. I placed foam around and between every side of the batteries. I put 2" of foam between the 2 inside batteries to give the eyelet space, keep it from rubbing.

I have an 8-ft cam-buckle strapped tightly around all 3 batteries and these cam-lock straps cinch nicely! A 4-ft strap and the cable lock go through the eyelet to pull the outer battery inwards.

I also had to make two more 4/0 battery cables. I planned the layout so the main ground is convenient right-front. And now without the battery tray, I can reach all the way in, over the batteries. I tightened all 6 battery terminal bolts after all 3 batteries were tied down, so these can be easily checked and tightened when needed.

Edited yesterday at 05:55 AM by jd1923

[jd1923]

Once I got to this point, I started thinking a thief could possibly undo the battery cables, loosen the straps and even with cable lock in place, slide out the outer battery, then steal them all. Oh No!

So, I had a 12x12x1/4" sheet of aluminum left over from another job and it became the perfect solution. Now besides a taking a crowbar to the battery door, a thief would have to cut the 3/8" hardened steel cable. Now these expensive batteries ain't goin' nowhere!

I'll cinch down the straps and cable lock again, after putting on some miles...

Ya gotta love the new look of our Epoch app! 900 Ah - Priceless! 😎

[tallmandan]

Wow JD!  You've gone an one-up'd those of us that have installed the 2 300 Ah Epochs.  Very impressed and good to know that this can be done.  I've been very happy with my upgrade to 600 Ah with the these two Epoch batteries but if I ever decided to upgrade to the 3000w inverter and try to run off-grid a/c then this would be the way to go! 

Thanks for sharing and thanks again for all the help and advice you share on this forum.

[CRM]

10 hours ago, jd1923 said:

I have an 8-ft cam-buckle strapped tightly around all 3 batteries and these cam-lock straps cinch nicely! A 4-ft strap and the cable lock go through the eyelet to pull the outer battery inwards.

Clean install. In the planning stages of adding solar/lithium and it's nice to know that 900ah can fit in the battery box. 

[jd1923]

9 minutes ago, CRM said:

Clean install. In the planning stages of adding solar/lithium and it's nice to know that 900ah can fit in the battery box. 

Thank you @tallmandan and @CRM and other forum members for the 👍!

@rideadeuce was my inspiration. Mike installed 920 Ah Epoch back in April 2024.

He purchased two of the Epoch 460 Ah Elite Series that come with Victron Comms, upgraded internal components and special cases. I didn't need the extras and preferred the lower price point of the Epoch Essentials Series. They call them Essentials, but they include the app, built-in heaters, internal protection, temp sensors and alarms. Even their Essentials Series batteries are industry leading!

Two Epoch 460 Ah Elite Series batteries just barely fit in the bay (see Mike's post linked below). Two Epoch 460 Ah Essential Series will NOT fit! The two side-by-side would be an inch too wide (the Elite Series batteries are much taller). Too bad, or I would have gone that way to begin with.

I didn't see that Mike secured his batteries into the bay. Likely they are so big/heavy, sitting on rubber, and since they fit wall-to-wall they would not budge! I felt the 3 smaller batteries should be strapped into place and I was also able to add a locking mechanism which minimizes theft worries. At 900+ Ah these are surely forever installs! 😎