Just a note, 16s (51.2V nominal) LiFePO4 is the standard "48V" size for LiFePO4 batteries. It doesn't have one extra cell. 4s is 12.8V, 8s is 25.6V, and 16s is 51.2V nominal. That's the standard. There are vendors who sell "48V" LiFePO4 batteries that are 15s, but you never want to buy those... its marketing junk and even though the "typical" voltage is 48.0V (3.2V x 15), it isn't the standard for 48V LiFePO4 systems. At 16s you typically charge to 56.8V and discharge to 48.0V or maybe slightly lower. There is no need to stress the battery by charging higher than 56.8V or discharging below around 46.0V. LiFePO4 is fully charged at 55.2V (@ 0 tail current), but BMS defaults typically need charging to 56.8V to balance properly. You don't charge or discharge all the way to the BMS safety disconnect voltages, that puts unnecessary stress on the BMS. Also, if you go 48V, use at least 2 AWG for the main battery cabling. That gives you 5000W+ of power capability with basically no losses. Particularly if you have three in parallel. If you want more than 5000W then go with 1 AWG or 1/0, but most 48V (51.2V nominal) RV builds just stick with 2 AWG. 5000W of continuous power with basically zero heat generation is one hell of a lot of power. Always use AWG tables for power transmission, NOT AWG tables for 90C temps. 2 AWG is 100A and at 51.2V nominal that is over 5000W. As long as the voltages are fairly close (and they likely will be), you can charge all the batteries in parallel just fine, even if they are at different SOCs. The current sharing will be wonky but once the charge cycle gets the batteries up to the target, they will all be at 100% SOC, roughly. One discharge / charge cycle later they will be perfectly matched. You don't have to worry about airflow with 300Ah of 48V (51.2V nominal) batteries in parallel. Your C rate is going to be so low that the batteries won't even get warm. e.g. 5000W will be 0.33C with that battery configuration. They won't even blink. Its a big nothing for LiFePO4. -Matt

I just finished my Sprinter electric build. Well, the basic system is in ...A massive learning curve... but with it, I can really appreciate what you're doing...VERY NICE!!!

Good looking job. The brackets that you flattened are actually adapters to install the batteries in a 23" server rack

Super happy to see you getting into doing videos on larger solar installs. I built out our current 2400w panel / 7.6kwh setup on our Born Free last year, but we're going full time and it looks like later this fall will be moving up to a diesel pusher. That means a new system, likely 6kw of panels and 20-30kwh of batteries. Those larger power needs also mean a new learning curve for 48v systems and split phase inverters. The fun never ends.

I built a 16.4 kwh 48v (nominal) battery for my motorhome using 16, 320ah cells. A 16s LiFePo-4 configuration produces 51.2v. The space it takes up looks ideal for the inside of a fiver, as it is long and narrow. The individual cells weigh about 12 lbs each so they are easy to handle. They are about 8.5 inches tall with the bus bars and studs to connect them together. The width and depth are 6.86" x 2.82" so the dimensions of the assembled battery are about 45.12" long by 6.86" deep by 8.5" tall. Most people put them in a compression fixture, so they don't swell extending their life to up to 8,000 cycles, so add a couple inches on each end for this. The last set of 16 cost me $1,726 including shipping and included flexible bus bars, studs and nuts. A good BMS will cost around $150. My 200A Heltec cost me $98 + shipping. Remember 200a at 48v is like 800a at 12v, so it should be more than enough. It's not just a drop in, because you need to top balance these cells before you connect them, so you need a variable voltage power supply to do so (maybe $50) and several days on the bench to get them all synched up. It's not hard but does take a little time, say 3-4 hrs of actual labor and the rest of the time waiting for them to balance. Still, that's a considerable cost and space savings. So, for around $1,900 ($116/kwh) you can build your own LiFePo-4 with more storage capacity than 3 server rack batteries that cost over $3,000 saving over $1,100 for a few hours work assembling and balancing the cells. Plus, they're about 100lbs lighter too. Just an option. Take care.

I'm like you James. I work alone 99% of the time. You find ways to get it done.

Once again it's the solar James show 😂. Have a good time

We have been doing 24/12v and 48/12v systems with my RV Solar company for a few years now. Many Brands are producing 48v server rack batteries. I have been using EG4 with all Victron for RV’s and Off Grid. 51.2v is quite normal at 48v We have also been using Hysolis Apollo and Battery Evo Walrus systems off grid and for class A’s So many options and all our customers are getting really informed on the archaic nature of 12v Nominal resting is 54.4v to 58.4v charging This is where I set a Multiplus ll 48

Beautiful install! Thats a LOT of power for that rig so I'm sure he will be very pleased.

Been watching almost since you started this channel and you never disappoint.

I was thinking of putting my own cells together and installing my own BMS. Looking over the rack mount unit you have is really a good price with a lot of built in options as well. Now thinking of using same rack mount batter thanks for info . Great job and great system.

Great job on the battery install, Looks great!

Someone has been watching Will.

Great video-thanks for sharing your install.

Looks good James! I like how you got the weight near centerline.

I’ve been using these 48v batteries for months for my solar home backup and they have been working very well so far.

Looks awesome. Nice box. You can wire them all up and just flip one breaker on at a time to charge individually.

James - you do darn good work!

Really nice solution for mounting the batteries.

Great video on 48v vs 12v I now understand cost difference on a larger system, You got Will Prowse on this RV solar deal you made my mind up on my boat system.

Insanely great!

Excellent job James! After first saying "each to their own" and respecting the owners choice, my comment involves my thought that this rv doesn't warrant the expenditure to install such a noble solar system just so the AC can be run. Regardless of the fact that money being no object, it doesn't make much sense...... A Firman 4000/3200 dual fuel generator only costs $800...... the fuel cost is insignificant in view of the cost of this solar system.

That is one handsome install James.

I had to move a big winch arrangement out of the shop one day. It was big and heavy. We could link our 2 10 ton over head cranes together to move it to the door, but to get it out had to come up with a better method. I just went out to the steel rack and grabbed several lengths of round stock and set it down onto them, hitched a chain onto our ancient old 16000 forklift and just rolled it out the door like nothing, had to keep grabbing the round stock from the back to the front but nothing to it. Definitely an interesting system you are building.

very imformative,thank you.🤩👍👍

Great build love it

Great video. You do good work.

the extra brackets should be for mounting the battery to a 2 post rack

nice work!!

Simply beautiful!

Have the same batteries but went with a sungold 10k all in one inverter. and a 12.5k watt gen as a backup.

So with all the additional weight, a fellow can no longer bring a chair and a fishing pole...lol.

you said the 15kwh is substantially less than 5.8kwh of your 1 battery - you meant it in reverse - right?

James, so has frame strength been considered here? All the solar gear in the front pass-through, generator on the tongue, regular cell on the tongue, dual propane tanks, and you indicated that the owner has a washer-dryer... Add all that up into an equation with a Lippert frame, and I've got to wonder if the A-frame connection to the deck frame is up to snuff...

Was there room to mount them flat against the back board? If they had added mounting holes on the bottom and sides for the included flanges, that would give you more options. If space allowed it, mounting them flat against the back board would give you lots more room to work with the inverter / chargers. One thing I would be concerned about is weight limits of the RV. I know my 36' RV allows about 2500 lbs of my stuff on top of the RV weight.

Great video, thank you! Do you need a step down 48v to 12V converter or the charger/Inverter already do that? Are you making the entire RV live, I mean, when the battery is on everything is powered? If yes, what kind of inverter/charger are you using what what power?

Gonna have high tongue weight. Nice pro job. Great video.

Recently you inspected a Fleetwood diesel pusher for my friend gary off of bell rd

Great video James! Since I having a class A that is a 12 volt vehicle still kind of hurts my head going to 48 volt house battery but I get the advantages. Maybe the way of the future, just make an RV all 120 VAC inside with a higher voltage battery and forget all the 12-volt stuff.

Working on a bank years ago, the safes are rolled in the same way,worked for the Egyptians

With the EV market down, decreased demand and increased supply, lithium batteries are getting cheaper and cheaper. Ive seen 13 cents per watt hour. Some are even cheaper than AGM now, unthinkable a few years ago.

I would hook up a fan to cool that system!

Is your friend/customer going to be using this in a hot environment or a cold environment? By placing those spacers between the batteries, you're turning it into one solid block with no airflow to cool the batteries. Ditto for putting wood and carpet around the perimeter. In a really cold environment, the internal heat of charging and using the batteries will act like its own anti-freezing heaters, albeit ones that are not in any way thermostatically controlled. In a really hot environment, you've just created a self-heating oven for the batteries. If that RV is spending its life in AZ, I'd remove the ABS spacers and maybe add a box fan on top to suck air between the batteries. Their metal cases are probably designed to carry away internal heat, and you just defeated that.

I might have stack mounted them in the same place with spacers to allow for easier access to the screens, front panels and more air flow... I hope heat isn't an issue.

The telephone industry has been using -48vdc for a century.

No sir, That 51.2 volts means that is where it cuts off which leaves around 12% and on the top end 55.2 volts is also where they cutoff of its setup correctly so you leave another 12%. Doing this is how they are getting longer life cycles. My inverters when they hit 51 volts switch to grid to power my house until sun comes up and charges batteries to 53.6 volts then it switches back to battery unless I manually switch back. If I run my batteries down to 48 volts I have 4% left. Running LFP or even lion batteries to under 5% harms them even though it says it doesn't by degrading the lithium faster.

Great Video & Info. Do yourself a favor and buy a hydraulic lift table at Hobo Freight. I have used one on my Alfa with the Basement Air, the Generator and I just did 2 of the 460ah batteries from your video on the Beaver. It was a great help removing the 6 Golf Cart Batteries and installing the Vatar 460 beasts. They put them on sale all the time. I never have a helper for this heavy stuff, and that cart makes life much easier, and it gets used for many things now as the platform lifts to almost 36".

go with two marine grade Mastervolt 24v batteries that have 230ah 6000wh each and are built to take a beating and waterproof housing.. They also have built in heaters for cold weather. I use a 12v system with a 550ah Mastervolt and can power a 3000w invertor for the air or microwave plus all the 12v.

These don't have an extra cell in them. 51.2 volts is the nominal LIFE PO4 voltage for a 48 volt system. If you look at your 12 volt battery it says 12.8 volts which is the nominal voltage for that system. Multiply your 12.8 volts by 4 and you'll see it's 51.2 volts.

James please share where you got the rails for the solar panels and the clamps. This would work perfectly to finish my solar on my truck camper.

Could you have put it all on a pull-out tray.? Still, great job. amazing power

Yay a battery sales video on a rv channel My favorite kind!

Im going with 12v system.

I would eliminate the 12v battery and the factory 12v charger by going with a DC 48V Step Down Voltage Reducer Converter to DC 12V. They can be purchased in any amperage you want.

Did Vater say anything about airflow requirements for those? I only ask as many server racks have various forms of forced air cooling. Great build btw.

I would wrap those batteries with corrugated plastic

330 lbs. plus two inverters and wire! How will this affect tongue weight! Heavy man! How will the truck suspension fare?

My OCD is triggered that two batteries have a red breaker switch, and the third has a blue one.. lol

👍sweet

To bad you couldn't get the wall mounted ones that they have on pre-sale.

I have 12v 310ah in my small RV and never seem to run low on power - won't 48v need a DC to DC charger?

51.2 volts is the standard 48 volt nominal voltage for LiFePO batteries. It's 12.8*4.

It sure seems like you would greatly benefit both productively and safety wise by having a wearable camera. Maybe like police or cyclists use that are either a part of glasses or go on your face like glasses or even as a headband. One handed work has got to be rather slow. Really like your content... and yes, even the boring stuff as its not so boring to me.❤ 😊

If you're going to go off grid with something like that better replace those air conditioners with the new ones just available that are inverter type. You know, like residential air conditioners have had for decades

I have and do service some 750MW lith battery banks, they are not worth it in my opinion, one has burned to the ground when someone saw smoke and opened the door no reason found moisture?, these are in 40x10 building electronicky/climate controlled 40 tons of HVAC to keep the equipment cool.

Your red battery frame-mount-post looks loose on your Beaver Patriot Thunder, the greatest Motorhome ever made. 3:51

24 volt is just fine, to be honest all you wil be doing is reducing the size of the required wires gauge the more bolts you have

at beginning you stated the system you installed is enough to run both A/C's - this is mathematically impossible unless those A/C's have variable speed compressors with incredible efficiency - I am not aware of rooftop window shakers to be so efficient and I pay very close attention to what is available. both cooling, tv or computer, fridge, perfect sun - I don't see more than 6 hours on a hot day Vatrer warranty = 5 years BattleBorn = 10 years To compare with BB = you need 4 batteries to match the power of Vatrer 1 rack system BB cost = $4,000 (maybe $3.5k with discounts) Vatrer cost = $1000 I have been a 12 volt tech for a very very long time. One thing I know to be true from the beginning until now - when there is such a disparity in price, every time the issue comes down to performance. There are many low priced options for lithium batteries - they are low for a good reason. BattleBorn cooks their batteries in the oven for testing to determine safety. I for one, do not want to wake up to my batteries burning. So - the question is - did Vatrer sacrifice safety and long term performance to be competitive? Based on my historical experience working with more brands I can recall, on just about every vehicle you can mention - over 15k installs - I would be scared to put this in my tt. $2k, $2.5k - sure. $1k = nope.

Air conditioner load calculations and recharge capabilities of 4 panels?

meanwhile my little honda 1000i will provide more reliable power to any battery system then all those solar panels..and FYI lithium server rack batteries in anything on the road is an accident waiting to happen..good luck with insurance...in substations we never use any of these for any reliable backup power never...same with AGM..

I know you're a fan of the solar generators, but rack full of these looks like it might be a good alternative for a home too.

Do you have plans to wire up an RV using a Ecoflow or similar power system as the house power?

Not sure if you hooked them up yet or not but with three in parallel you really want to go to bus bars using equal length wires rather than just paralleling them in line with each other. This is because they will actually charge and discharge unevenly especially under heavy load if they aren't paralleled using bus bars. I've seen videos where people test this and the unbalanced can actually be pretty significant.

I purchased that 460 ah Vatrer and the Bluetooth only has a range of about 5 feet☹️ is yours any better than that? To get a Bluetooth reading in the coach, I have to lay my phone on the floor above the battery.

Has the awning #1 failed yet? 😁

I wanted to convert my Newmar to Lithium house batteries but I live in New England and often will camp in the freezing cold, I don’t think this is really good for charging and draining lithium batteries… they don’t like the cold.. what do you think?

Server rack batteries may not be the way to go for mobile. Unless stated for such purposes or unless someone who knows how to find potential problems and qualify it, server racks shouldn’t be used for mobile. Mounting them, control panel up puts the most strain on the lowest cells and causes the buss bars to extend and compress with every bump. Since they told you it’s ok to mount them as such, I hope you got that in writing. Very few server rack batteries have cells are secured for long term mobility, especially in that orientation. I hope I’m wrong.

My only concern is the heat coming from your inverters and how hot those batteries are going to get. Might want to make sure you don’t exceed 140 deg f. Just my 2cents worth.

Where are these batteries made?

So you alienate about what 1200 to 1400 pound of gross vehicles weight available

$1100 per battery? 😲

So your customer/friend understands the clear superiority of a 48V system and you are the "expert". Interesting!

👍🤛🙏🔌😎🦅🇺🇸