SOK Lithium Upgrade with Portable Solar Array

[jgbagley]

I am starting on the journey towards a DIY Lithium + Solar installation from my existing AGMs on my 2019 FC 26RB. I currently have 2 x 90W panels on the roof with an open plug on the roof to add a third. We plan on doing a lot of boondocking and working full-time from the road, so I would ultimately like to have 400Ah of Lithium and 800W of solar panels. To get there, I will need to relocate the batteries from the box on the A-frame to under the seating in the front by the dinette. From my reading so far, I understand that I will need to:

• Replace my existing charger with a lithium compatible one (PD9100 Series)
• Add a battery monitor (Victron BMV-712)
• Replace the existing solar charge controller with a Victron 100|50 MPPT

I plan on keeping my existing inverter (WF-5110R) as I don't plan on using any large appliances (AC/Microwave/etc.) I mainly just want to have enough juice to run all necessary electronics during the workdays even if we have a few cloudy days consecutively.

What I am uncertain about is how to go about wiring this so I can plug in a portable solar panel array to my solar charge controller which will be collocated with the new batteries. Is there a suggested method to doing this? I assume I'll need to repurpose the existing wiring from the external battery box, but I haven't been able find any specific instructions on this.

Also, I was thinking about going with a SOK LiFePO4 instead of Battleborn as they are roughly half the price of BB and also have a built in BMS and great reviews. Anyone have good argument against using SOK?

[daleyocum]

I messed around with putting my ground based-solar in parallel with the roof solar but found the characteristics were so different it wasn’t very efficient. In the end I installed another Victron Solar controller inside the trailer and then plugged the ground-based solar panels into that. That also lets you by cheaper external panels that don’t have a controller.

By doing this you both get to monitor on your phone how well the external panels are doing but are also sure the two solar controllers are compatible. Many external panels use pretty cheap controllers and many aren’t lithium compatible.

Can’t help on the batteries. These are a big investment. I personally went with Battleborn for their reputation, support and warranty.

You’re building out quite a system. While you’re at it I’d consider installing a Victron. Multiplus 3000w inverter/charger. That way you can use all the AC outlets in the trailer AND run the appliances just like home. I have 600w of solar and 500ah of battery and we use a LOT of 120v appliances and never get below 50%.

[jgbagley]

Originally Posted by daleyocum

In the end I installed another Victron Solar controller inside the trailer and then plugged the ground-based solar panels into that.

So with this method, how specifically are you plugging the outside panels to the inside solar controller? Are you able to do this with the existing cabling running from the battery box or you added something?

[drbrick]

We have 2x100 SOKs and are very happy with them - we have 200w solar on the roof + 160w suitcase - note that the SOK are best interior install not really meant for exterior battery box. See our install here: the-lithium-experiment-introduction/

[Rdavenp3]

I added 2 of the SOK 206ah batteries this spring. I have tested them driveway camping and so far they seem to be working well. I have 400w of solar on the roof and Victron 100/30 controller. You’re also going to want a shunt to monitor battery state of charge. The Victron BMV712 is popular, but there are alternatives if your budget is tight.

[daleyocum]

Originally Posted by jgbagley

So with this method, how specifically are you plugging the outside panels to the inside solar controller? Are you able to do this with the existing cabling running from the battery box or you added something?

I rewired that solar plug on the tongue to feed into the second solar charge controller mounted inside. I also reversed it’s polarity to match what the whole industry does (outside of Zamp.)

[rich.dev]

Originally Posted by jgbagley

]Replace my existing charger with a lithium compatible one (PD9100 Series)

I have a 2016 26U and just recently replaced the stock converter (Parallax 8355) with a PD4655LV. Randy from Bestconverter suggested I replace the stock converter with the PD4655LV and not the PD9100. The 4655LV will work with lithium or lead acid batteries.

[Kawboy01]

I just installed a SOK 206Ah lithium in our 21GT27FBQ in front compartment. Upgraded the converter to PD9145ALV, installed a Victron Smart Shunt w/BT (instead of the 712), Renogy 20 amp DC to DC charger, various buss bars, switches, breakers and fuses. Used 4 gage pure copper welding cable and lugs. We had the stock AS solar so some of the cables re reused as was the stock 1000 watt inverter. May upgrade this later if we feel the need for more power. We also have a Renogy 200watt suitcase.

[Ch47d1sg]

A&P vintage trailers will be doing a makeover of our AS installed solar system. 19fc30rbt will get a lithionics 315ah lithium, 4 addtl Renogy 100 watt panels, victron 150/85 mppt with BT, xantrex sw3012 inverter, xantrex control panel, and sterling dc to dc converter amongst. Am looking forward to the upgrade. Will also convert the polarity of the external plug as daleyocum suggests for additional panels if needed. Looking forward to completing project flying Warrior

[GammaDog]

I didn’t see anyone mention a DC/DC charger between the tow vehicle and your lithiums. Apologies to anyone who posted that thought already! I use a Victron Orion. I elected to reuse the factory 4 ga from the battery box to handle a bunch of stuff now located in the battery box. A Victron solar controller, the TPMS repeater, an Anderson 50 amp disconnect for the compressor, jumper cables, 12v outlet, etc.

I added a true battery disconnect and eliminated the Use/Store switch since Battle Born says they don’t like their batteries in storage at 14.4 v for long periods of time.

Don’t overlook true bus bars as the place where both pos and neg legs congregate. Also, fuses or breakers on each leg and a main fuse.

AM Solar has some great, complete diagrams of systems they install. You might find a diagram there that is close.

[jimdelane]

Rdavenp3 had a good point in that you do not need the Victron 100|50 MPPT solar charge controller. He suggests the Victron 100/30 controller. It is more than enough for 180w solar. Install 24V panels if you can as you will get better performance.
GammaDog makes a couple of good points. If you plan to charge the battery with your alternator, you need to consider a DC-DC charger or a Sterling Alternator Protection Device - depending on the alternator.
The Victron BMV-712 is excellent. You might consider the Victron SmartShunt. It is the same battery monitor without the guage. The guage is wired to the battery. The Victron SmartShunt is bluetooth with all the same functions as the 712 and about $100 less. My experience is that with the bluetooth smart phone function, nobody ever looks at or uses the monitor other than to see what the voltage is and that can be done with a cheap $5 LED voltage monitor wired to the battery.
Depending on your battery storage compartment, you may consider purchasing a larger Ah battery. There are 150, 202, 300 and 400Ah batteries available. More energy in a smaller space with less cabling is always good.
I heard SOC has been having production problems and backordered.
Other batteries with good reputations and good warranties include:

AMPS Lithium
https://lithiummarinebattery.com/shop

LiFeBlue Battery
http://www.lifebluebattery.com

ReLion
https://relionbattery.com/products/lithium

SmartBattery
https://www.lithiumion-batteries.com...-rv-deep-cycle