Need help shedding 3/4 ton - Lithium Battery project

[Boatycall]

Long story short - I'm an Electrical Engineer. Several years ago I was able to get some very expensive 145AH AGM batteries, brand new, literally by the pallet, for free.

Needless to say, I went to town - I set up my Eagle Cap 1160 with a half dozen, and my 24' trailer, "The Shotwagon", with 6 more. Well, they weigh 125lbs each. That's literally 3/4 ton just in batteries.
But as the system sits, I can easily run the roof air with both solar systems tied together, off the inverter.

Well, fast forward to 2020. It's been several years, and those batteries are starting to fade. Time to kill two birds with one stone.

I'm looking at Lithium batteries, to go on a diet. Both the Morning Star controllers and the Magnum Inverter/Charger support the voltage steps/modes necessary for lithium battery charging. And all the batteries I've been looking at have their own BMS built-in, so technically, they are 'plug and play'.

The setup I did - (The pic is kinda hard to read due to size limits)
TC -
(6) batteries
Magnum Technologies 3kw Inverter/125a DC Charger
(8) Grape solar 100w panels
Morning Star MPPT60 solar controller

The Shotwagon -
(6) batteries
(4) Unisolar 145watt 'Peel and Stick' solar panels
Morning Star MPPT45 controller
Xantrex 1800w inverter
*No* 110/DC charger - charges by either solar, or a 100a 4ga disconnect between the truck, TC, and trailer - truck charges while driving, camper's Magnum charger when parked.

My questions:

**Please help me out here and limit responses from actual Lithium Battery owners**

* Battleborn seem like the ideal setup, but they are the absolute most expensive of all the ones I've seen. What do you run?

* They say the "actual usable Amp Hours" of a Lithium battery is near 100%, where as lead-acid and AGM, they claim, is only 40-50% of rated AH - what is your experience? The claim is that 300AH's of Lithium can, in effect, replace 600AH's of AGM's.

* How does the truck charge wire handle being plugged into Lithium's?

* Any heat issues on high charge/discharges?

* Any special considerations when doing the swap besides a compatible set of charge voltages?


System design--


Grape Solar panels - 76 holes, only one small leak...found it and fixed it right after that rainy trip.


Three of the six batts in the trailer, inverter and solar controller --


Three of the six batteries in the TC - two facing and one to the right on it's side--



Here, on a good day, getting the full 60amps charge the TC's solar controller can do--

[n0arp]

Freep wrote:

jshupe wrote:
Lots of questions about what they're doing with so much power, but it really isn't all that much, especially if you want HVAC.

One thing we love about our TC is that when it gets too hot or too cold, we go somewhere else.

We can do the same thing with our fifth wheel, but like HVAC regardless.

[Freep]

jshupe wrote:
Lots of questions about what they're doing with so much power, but it really isn't all that much, especially if you want HVAC.

One thing we love about our TC is that when it gets too hot or too cold, we go somewhere else.

[Bedlam]

In my overcast piece of the Earth, I am lucky to get half my rated solar. In the winter, I only get 8 hours of daylight (summer is 16 hours). If you look where people live, you might understand that not everyone can chase the moderate weather and some of use still work full time. Having larger capacity is really not that much.

[restlessways]

joeshmoe wrote:
boaty's been around here for a long time and given a lot of helpful advice. Might want to slow your roll taking joking jabs at him, his wife(even jokingly)and his setup. His setup is badazz. He knows what he's doing.

I haven't seen anybody taking jabs at him. What are you reading?

[restlessways]

jimh425 wrote:

restlessways wrote:
His wife watches TV and videos all day and heaven knows what else. And there are very large pine trees all over the place so the sun is intermittent.

I think this is a joke, but if it’s not, modern tv/video doesn’t take anywhere near his amount of power. 😄

Not a joke at all. As others have pointed out - run the air conditioner all the time while running the tv, dvd player, microwave, hair dryer, etc., and it adds. up.

[n0arp]

Lots of questions about what they're doing with so much power, but it really isn't all that much, especially if you want HVAC.

We have 2925W of solar and 22.8kWh @ 48V (equivalent to 1800AH@12V) LiFePO4 and I know of a few with larger systems. We run our AC and/or heatpump via thermostat while boondocking (30K mini-split) and only run the generator on rare occasions of extended inclement weather. So I'm not sure what that one guy is doing, but that's what we're doing with a fairly sizable (but definitely not the largest out there) system.

Even with the size of our system, the math doesn't work out if you have rooftop AC units.

Right now we're also providing power to a neighbor's rig that is having issues.

[joeshmoe]

boaty's been around here for a long time and given a lot of helpful advice. Might want to slow your roll taking joking jabs at him, his wife(even jokingly)and his setup. His setup is badazz. He knows what he's doing.

[jimh406]

restlessways wrote:
His wife watches TV and videos all day and heaven knows what else. And there are very large pine trees all over the place so the sun is intermittent.

I think this is a joke, but if it’s not, modern tv/video doesn’t take anywhere near his amount of power. 😄

[jaycocreek]

He's got MAJOR money into it. And he's still running his generator for at least 3 hours per day. He'll never get his money's worth.

Yup,that don't make sense..I have looked into solar and it can be quite expensive and generators are getting cheaper..Lithium batteries are impressive in AH that can be used but weather seems to be an issue with them now...I just can't wrap my head around that much per battery....Maybe if I win the lottery..lol

[restlessways]

Freep wrote:

What is this guy running that requires so much power? And how much sun is available?

If you're using an inverter a lot, it's often a better idea to collect and store your power at 24 or 48 volts. Get a higher voltage inverter and then step down to 12v for your 12v system.

His wife watches TV and videos all day and heaven knows what else. And there are very large pine trees all over the place so the sun is intermittent.

[Freep]

restlessways wrote:

I own a private campsite and have a neighbor who built a massive solar system. He's got 22 batteries and something like 2000 watts of solar panels. I forget exactly. He's also running a 3k inverter/charger and all the associated wiring/fuse blocks, controllers, etc. He's got MAJOR money into it. And he's still running his generator for at least 3 hours per day.

What is this guy running that requires so much power? And how much sun is available?

If you're using an inverter a lot, it's often a better idea to collect and store your power at 24 or 48 volts. Get a higher voltage inverter and then step down to 12v for your 12v system.

[restlessways]

Kayteg1 wrote:

restlessways wrote:
Those Battle Born batteries are great if you can afford them. I just couldn't stomach spending $1,000+ per 100 ah..

OP did not say how many he is considering, but coming from 3/4 tons, that would be like 10?
Or $10,000 spend just on shaving few hundreds lb from 12,000 lb (?) rig.
Sure not solution for average camper.

He said he has 12 AGM batteries right now, and was looking to cut that in half since lithium can be discharged to zero vs the 50% on lead acid. Still, $6k+ for batteries is nutso, in my humble opinion.

I own a private campsite and have a neighbor who built a massive solar system. He's got 22 batteries and something like 2000 watts of solar panels. I forget exactly. He's also running a 3k inverter/charger and all the associated wiring/fuse blocks, controllers, etc. He's got MAJOR money into it. And he's still running his generator for at least 3 hours per day. He'll never get his money's worth.

For myself, I have found I really don't need to consume that much power. I use a combination of a 100 watt panel, a 2k GoPower inverter, and a Honda 2200i generator along with the aforementioned twin 6 volt Duracell golf cart batteries. It provides me with more than enough.

[Kayteg1]

restlessways wrote:
Those Battle Born batteries are great if you can afford them. I just couldn't stomach spending $1,000+ per 100 ah..

OP did not say how many he is considering, but coming from 3/4 tons, that would be like 10?
Or $10,000 spend just on shaving few hundreds lb from 12,000 lb (?) rig.
Sure not solution for average camper.

[restlessways]

Those Battle Born batteries are great if you can afford them. I just couldn't stomach spending $1,000+ per 100 ah. I thought about it but just decided to go with a couple of Duracell 115 ah 6 volt deep cycles which I got on sale for $100 a piece. They last 5+ years. Yeah, you have to add water sometimes, and they're heavier, but that's the trade-off. The Battle Borns would have to last 25 years at that price. The EV people say the prices on batteries will be going down, but they just keep going up.