Lets talk about LITHIUM Travel Trailer Batteries/Inverters/Solar (v2.0)

So previously we talked about travel trailer batteries:
https://www.tundras.com/threads/lets-talk-about-travel-trailer-batteries.88983/
The short of it was that we bought a new trailer, ditched the single 12v battery that it came with and went with 2 6v Interstate batteries instead, hoping for multiple day capacity, was let down by the setup.

We ran into 2 problems:
1) Capacity wasn't what i expected it to be, ended up running the generator more than what i wanted to.
2) First-World-Nespresso-Problems. We wake up on the early side (6am) and we couldn't turn on the espresso maker until the generator ban is lifted at 8-9am. I tried making espresso the night before and just heating it on the stove in the morning but the wifey didn't like it.

Our next couple trips were with power hookups so it wasn't much of a problem, but in about 4 weeks we are going dry camping again and started doing research on the problem and solutions. So from what i understand with the golf cart batteries you really only get about half of the capacity since you dont want to discharge lower than 12v before damage happens.
I had a $200 Amazon credit and started looking into Lithium batteries and doing some research. I ended up on this mamajam:

FOIIOE VESTWOODS 12V 300Ah LiFePO4 Lithium Rechargeable Battery, 4500 Cycles, 3.84kWh, 100A BMS, Low Temp Cut Off, IP65, Replacement for RV, Solar, Marine, Golf Cart

https://smile.amazon.com/gp/product/B0B4BC7MD4?ie=UTF8&th=1
Now after doing some research, i found out that outside of the expensive batteries (Battleborne/sok....) all the others (amperetime/chins/vestwoods) are the same thing in a different case.
So i ended up opting for this guy pretty much based on cost. There was a $60 coupon minus my credit, it ended up being $699 for a 300ah battery.

So this should solve my capacity problems.
Edit: This order was canceled since the above battery only has a 100a BMS, i purchased a 200a bms from a different mfg, more info a few posts down.

Now, its a little bit trickier with the Nespresso (Citiz with Milk) machine. This damn thing takes a lot of juice. When i would run the 2 2kw inverter generators throttle up and down quite frequently. I have an idea that it pulses the heating elements instead of constant draw and would make my generators hunt.
So i started to look at adding an inverter to be able to run the coffee maker off of.

https://smile.amazon.com/gp/product/B08ZLWGY8G?ie=UTF8&th=1
I ended up picking this one for 3 reasons, pure sign wave is a must for inductive loads, it has a "high power link" (meaning regular Ground/Neutral/Hot connectors....more on this later) and a remote that shows battery voltage output voltage and frequency and watts being used.

Soooo, hear me out, what i'm thinking of doing is just adding a 30amp female plug to the "high power link" terminals like this:

Then i can just use the 30 amp cord that came with the trailer and plug it into the side of the trailer just like having sore power. I would be able to turn the inverter on/off (via the display remote) as needed and still run everything else off 12v.
I did some research and it sounds like a common simple solution, only thing to watch out for is to flip the breaker for the battery charger so you aren't trying to charge the battery with the battery).
The other option would be to run from the inverter to the power panel and either pick a few outlets to power from the inverter or have some sort of a transfer switch, but i have no idea how they ran wires and would probably have to pay someone to do it.
I plan on mounting the inverter to the wall in the storage pass through. I also thought about installing a outlet box on the frame like this so i dont have to have the door open:

It looks a little big/bulky so i'm not sure about that.

I'm not sure how they passed wire from the battery inside the trailer. There's an underbelly skirt that runs the length of the trailer, so i'll have to figure that out. They also ran some pretty anemic low strand count (10ga i think) wire from the battery to inside the trailer, i wouldn't mind running some thicker stuff while i'm at it.

Next purchase is going to be two or three 100w solar panels to make a diy folding solar array with a mppt charge controller to get things topped off. From my research i would need 900w of solar with 5 hrs of direct sunlight to fully recharge a discharged the 300ah lithium battery, thats bananas...so i think/hope 300w will be enough.
I also see that this guy is on sale, but i think i would probably be fine with the inverter's display to keep an eye on things.

But let me know if it would be a worth wile purchase.

Thoughts?

 

It’s a 300ah battery but that’s capacity, how many amps can it safely deliver at one time. 12v at 100a is 1200w. Through an inverter it’s gonna be less. Probably 900-1000w at 120v so you’re looking at 8-9 maybe 10 amps on 120v.

Just spitballing because I don’t know the specs of that battery.


*edit* went to check specs, depending on load I’d be wary of burning that batter out. It’s why a lot of people do two batteries in parallel, for the discharge rate and not necessarily the capacity.

• Max. Continuous Discharge Current: 100A
• Max. Continuous Charging Current: 100A
• Max. Permanent Discharge Current: 200A 10Sec

 

Good point. I'll have to look into this.

Shouldn't be drawing more than 1200 wats at any given time. I bet there will be some surges in the 1500w range when the coffee pot fires up, but we'll below the 2500w 10sec max

Edit:
So I just used a killawatt on our other Nespresso machine.
It mostly hits about 1200w for it's brew time but saw it hit 1300 for a split second. Should be fine.

 

As far as coffee get a jet boil and an Aeropress. You will solve the power problem and upgrade your Nespresso 300%! Seriously if your wife is into coffee. Really nice for travel or camping.

 

As you may have guessed, we really don't like to rough it.

Yeah, I thought about this. They make pump style Nespresso makers as well that was a cheap solution, but still need more battery capacity even without the Nespresso machine. Powering it early in the morning is a plus.

 

I'm glad that @eick pointed out that there is a 100amp bms, i reached out to the seller and asked if it would fit my needs and they basically said "probably not" which i appreciate their honesty. They said if you pull more than 1250w then it will go into protect mode and you have to connect a charger back to it to free it up. Not something i want to deal with. They offered to cancel the order if i like, which i did.

I went back and kept looking at 300ah 12v 200a bms and ended up just ponying up the extra $125 for the AmperTime one that seems like everyone likes.

$660 Litime 12V 300Ah Lithium LiFePO4 Battery, Built-in 200A BMS, Max 2560W Power Output, Easy Installation, 4000+ Deep Cycles, FCC&UL Certificates, 10-Year Lifetime, Perfect for Off-Grid, RV, Solar.

https://smile.amazon.com/gp/product/B08K7HZ6KZ?ie=UTF8

Now i just need to find some solar panels

 

This is getting expensive.

Amazon has 2 100w solar panels for $142, the "normal" sale price is 2 for $150 that i haven't seen in a bit, so i went ahead and ordered two sets (4 total)

$166 Renogy 2PCS Solar Panels 100 Watt 12 Volt, High-Efficiency Monocrystalline PV Module Power Charger for RV Marine Rooftop Farm Battery and Other Off-Grid Applications, 2-Pack 100W

https://smile.amazon.com/Renogy-Mon...refix=renogy+100w+solar+panel+2,aps,85&sr=8-3

I've got two options for charging the battery, i can run them in parallel and get a cheap pwm controller, or series and get a mppt.
From what i understand if you have 100% sunlight, then parallel is easier, but if one panel gets in the shade then the array goes down. Mppt (with panels in series) takes the higher voltage so its easier to get to the 14v that lithium likes to charge at.

 

You have the parallel vs series backwards, parallel is better for shade.

The problem with parallel is that you’re gonna push more amps so you may need thicker gauge wiring.

If you have 4 then consider doing a 2s2p configuration maybe so you’re somewhat protected if two of them end up shaded and you won’t need wiring that can handle 20 amps over a long distance

 

My buddy brought a similar instant coffee maker and thought he could just plug it into his AC outlet on his Gladiator - I chuckled. The morning he tried to use it, it didn't work, so he had to plug it into my 2000 watt inverter that was connected to a high output alternator. Much cheaper route than that expensive battery. Sure you have to run the engine but does that break the no generator rule in the morning?

 

Yeah im still trying to decide how to really set everything up, i originally wanted to just do 3 panels, but with the deal of the 2pk i just jumped on 2 sets.

What i'm thinking, is if we aren't using too much power, i'll just use 2 panels in series. If we need more power, then i'll break out all 4 panels in a 2s2p configuration.

Here's the wiring diagram i'm thinking. thoughts?

 

Not a bad idea. I remember reading some people were having a helluva time getting HO alternators to cooperate. No problems?

 

No problems at all, works great.

 

Just make sure you’re using wiring that can handle 250 amps if you’re gonna use a 250 amp breaker. Size breakers and fuses for the wire not the load

 

My thoughts was that it has a 200a bms built in but can surge past it for a few seconds, but looking at wire gauge, i would have to have 4/0 gauge wire which seems nuts.

The main reason i wanted a breaker on between the battery and inverter is that i read that it doesn't ever really shut off (even with the power switch off, due to the remote display), so i figured a breaker would be good to be able to completely shut it off if i'm not using it.

what do you think sizing wise i should use? I could open the unit and see what size fuses are there and just match a breaker with that sum.

 

Keep the 12v runs as short as possible and only use copper wire not aluminum.

Cheaper to buy welding wire than trying to buy from a electrical supply type place.

If it were me I’d probably mount the inverter on top of the battery and connect it with a super short run

What you don’t want is a short on a wire that catches fire at 150 amps when the battery or breaker won’t shut off til 250. Fire not good

 

Sorry also to add: I’d do a one to two foot run of some 1 or 2 gauge. Should be fine

 

I've got some 1/0 welding wire leftover, so that should do the trick.

 

Build your own setup using Nissan Leaf batteries.

About $2500 total investment and you can run two AC units, double slushee machine all the lights and stereo you want all day long, and if needed fully charge in less than 2 hours.

This is my buddies setup on his ATC.

Bench Testing


Installed

 

You're not charging that with two solar panels lol

 

6 100watt panels and a 5k onan.

I’ve boondocked with them where they haven’t fired up the generator for 4 days. They only used 1 AC unit and no slushy machine lol.

 

Not gonna lie a slushie machine while camping sounds like something I need in my life

 

We've looked into them before.

They ain't cheap.

 

All that viktron stuff looks like more than 2k....

I looked into c-max batteries also

 

It honestly needs to be part of every camping trip. 1 side for adults, 1 for the kids.

But it pulls some watts lol

 

Yea I don’t care I only ever camp with full hookups lmao

 

Inverter was delivered today.

All the screw posts on the display unit were sheared off so the case comes apart.


I contacted the seller, we'll see what happens.
Part of me is tempted to just return it and buy the Renogy inverter, I really liked the display though.

 

I just installed a Xantrex freedom x2000 in my Tundra. A little pricey but it seems like a good unit and the display head is nice albeit wired.

Renogy inverters and inverter /chargers you can get the same guts on Amazon a little cheaper I think. They appear to rebrand their stuff.

 

Xantrex seems like its to oem option for trailer manufacturers, i see them a good amount in trailers when i was researching them.

Update:
Got a response from the seller. Looks like they are going to ship me out something, not sure if its a whole new unit or just the display. We'll see.

 

I'd say get off grid for camping. Go somewhere you can run your generator at 3 AM if you want to. Not only will you save money, but camping away from people is the entire point of camping, isn't it?

 

At this point we use the term "camping" rather loosely....we're more into the glamping or condo-camping realm.