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Server rack battery in RV

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Farm

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Looking for input...I’m replacing the old lead acid 12v battery in an RV with a server rack battery. My choice is between a 12v 400ah or the 48v 100ah with a step down converter to run the 12v RV fridge. I expect losses in the converter but don’t know how much.

Thanks
 
Mine is not a server rack but I stayed with 12v to avoid the up and down conversion. Either way the energy is the same.
 
Firstly I would question your reasonings for a server rack over a traditional cased battery for the RV. No matter where you put it, RVs are not the cleanest or driest places out there.

Need more details as to why you would are looking at 48v, how you plan to charge, do you require 120v etc.

For example, if you have an 18 foot bumper pull and want to charge with solar, you will not have enough room (most likely) to overcome to Voc requirement of the MPPT controller.

On the other hand, if you say this is for a Sprinter type van you are building and you want to charge off the engine when driving, then 48v is most likely not the best choice.

Main reason people turn to 48v is to reduce cable size.

So in other words, more details.
 
The battery will be charged with a generator as the RV is parked in the shade when camping and solar would produce little. I’d like to power the fridge and furnace controls with stored energy and run the generator every few days to top off. I’m thinking the server rack battery has a good capacity and could be used inside the house or shed when not camping. I like the 5KWH size. Is there a better battery you would recommend?
 
Farm said:
The battery will be charged with a generator as the RV is parked in the shade when camping and solar would produce little. I’d like to power the fridge and furnace controls with stored energy and run the generator every few days to top off. I’m thinking the server rack battery has a good capacity and could be used inside the house or shed when not camping. I like the 5KWH size. Is there a better battery you would recommend?
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If I read correctly you are looking at a buffer to keep the generator going?
What kind of RV? 5th, travel trailer, Class ABC. I ask as there are electric jacks, possibly slideouts and levelers to contend with.
You mention furnace controls, do you plan on running AC or electric heaters? 5kwh will not last long.
Did the fridge come with the RV? I ask as you are stating a three way RV fridge, which is not that common. Most are 2way - propane and AC. Either way, RV fridges are notoriously inefficient. then again, you might be referring to a newer cooler type...............??

While people have used the server rack batteries in an RV, I prefer to use a automotive style. Like this. Same price range same output, just a little bit more suited for an RV in my eyes.
 
Its an old Airstream. I want stored power so I run the generator less. I’d just run the fridge (aftermarket 12v only) off the new battery. Seems like 1KWH a day should run that. If I need 120v I’ll run the generator and recharge at the same time. I don’t remember if 120v is needed for the furnace or not. If not then 12v would be used for furnace controls and fan. It is propane fueled.
 
Farm said:
Its an old Airstream. I want stored power so I run the generator less. I’d just run the fridge (aftermarket 12v only) off the new battery. Seems like 1KWH a day should run that. If I need 120v I’ll run the generator and recharge at the same time. I don’t remember if 120v is needed for the furnace or not. If not then 12v would be used for furnace controls and fan. It is propane fueled.
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I would stick with 12v for this service. Good time to review the charging system to get the most charge while the generator is running.
 
Farm said:
Its an old Airstream. I want stored power so I run the generator less. I’d just run the fridge (aftermarket 12v only) off the new battery. Seems like 1KWH a day should run that. If I need 120v I’ll run the generator and recharge at the same time. I don’t remember if 120v is needed for the furnace or not. If not then 12v would be used for furnace controls and fan. It is propane fueled.
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I think for the most part Airstream used Atwood propane furnaces. So you are correct, only 12v needed to ignite, but the fan will draw 12v as well. If memory serves me correct about 48 watts to run the fan on a 2ok btu unit. Something to calculate with your fridge to get runtime.

Getting back to 12v or 48v, there is no advantage I see here to go to 48v. Down converting will only cost you inefficiencies.
 
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Thanks for the help. I’ll be shopping around for 12v battery options.
 
When I upgraded to LiFePO4 I spent considerable time looking for a place to put the new DIY batteries inside the camper. After taking lots of measurements and testing locations with a CAD tool I had to switch from my original location to a secondary location. Do you have room for a full size server rack battery in an Airstream?
 
If you are handy this may be a case where a self made battery is better - eight EVE 280ah cells with two Overkill bms’s will give you 560ah battery at 12v -bigger, cheaper and easier to design into an interior space.

With either direction you will probably need to replace the 12v converter (originally battery charger). It is likely NOT good for your lithium batteries.

Get a really good battery monitor- like a Victron Smartshunt- that will help you predict how long your batteries will last at the current battery draw.

Good Luck
 
Rocketman said:
With either direction you will probably need to replace the 12v converter (originally battery charger). It is likely NOT good for your lithium batteries.
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For house batteries, most if not all, have no charger, but just a DC power supply set at about 13.6vdc
 
There’s lots of room for batteries in the old airstream. The previous owner removed the drawer under the sofa which is very near the converter and dc distribution panel. I could fit anything a foot tall and 5 1/2 feet wide there. Three server rack batteries would fit but I am advised to use better sealed designs.
 
Farm said:
There’s lots of room for batteries in the old airstream. The previous owner removed the drawer under the sofa which is very near the converter and dc distribution panel. I could fit anything a foot tall and 5 1/2 feet wide there. Three server rack batteries would fit but I am advised to use better sealed designs.
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Sounds good. Don't forget about ventilation. My batteries don't heat up much but the inverter and the solar charge controllers sure do.
 
What about the factory converter charger do plan to change it to a LifePO4? I took mine apart and installed a toggle switch so I could turn it off.
 
My two concerns with this would be weight and vibration resistance. With regard to the second concern, you may want to consider rubber feet, or some other vibration reduction system, underneath the case. With regard to the second concern check your weight capacity. A DIY will be lighter but with the case you get the benefit of protection for the batteries and some fire protection. If I were starting over I would give this serious consideration.
 
Farm said:
Three server rack batteries would fit but I am advised to use better sealed designs.
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Never advised, just suggested elsewhere. I just see no benefit of a server rack battery in an RV. Even more so mounted on the floor under a sofa. :)
 
Cdkipp said:
My two concerns with this would be weight and vibration resistance. With regard to the second concern, you may want to consider rubber feet, or some other vibration reduction system, underneath the case.
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Never seen a battery mounted in a car, tank, Humvee, bus, 18-wheeler, excavator, backhoe, bulldozer, tractor, airplane, fighter jet, helicopter, four wheel drive, race car, dragster, motorcycle, RV, trailer, or UFO that was not DIRECTLY mounted directly to a metal plate. Wonder why?
 
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I believe the whole vibration thing of an RV is a bit overblown. If it survives UPS/FedEx/USPS/DHL to be delivered, the RV is pure comfort.
 
MrThisIsME said:
Never seen a battery mounted in a car, tank, Humvee, bus, 18-wheeler, excavator, backhoe, bulldozer, tractor, airplane, fighter jet, helicopter, four wheel drive, race car, dragster, motorcycle, RV, trailer, or UFO that was not mounted directly to a metal plate. Wonder why?
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time2roll said:
I believe the whole vibration thing of an RV is a bit overblown. If it survives UPS/FedEx/USPS/DHL to be delivered, the RV is pure comfort.
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I concur. My two batteries are firmly attached to the floor of my RV which sees plenty of rough roads. I do put in plenty of strain relief for the cables.
 
time2roll said:
I believe the whole vibration thing of an RV is a bit overblown. If it survives UPS/FedEx/USPS/DHL to be delivered, the RV is pure comfort.
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All you need to do is look at the military for an example. M1A2 has six batteries all mounted on metal and clamped in a metal cage no less. This thing can drive down roads at 40mph, while firing, that most pickups could not do 2mph down. It can jump off cliffs, take small arms fire easily, cost $10mil each, yet batteries are mounted solid.
 
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Rocketman said:
If you are handy this may be a case where a self made battery is better - eight EVE 280ah cells with two Overkill bms’s will give you 560ah battery at 12v -bigger, cheaper and easier to design into an interior space.

With either direction you will probably need to replace the 12v converter (originally battery charger). It is likely NOT good for your lithium batteries.

Get a really good battery monitor- like a Victron Smartshunt- that will help you predict how long your batteries will last at the current battery draw.

Good Luck
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Rocketman makes a good point. I built a 48v battery out of 16- 280ah cells that fits nicely between the frame rails under the garage floor of my trailer. Yes, my underside is insulated, so not greatest access, but once built, you don't really need to be accessing it. I built an aluminum frame that swings down, and strapped all the cells down with a long, wide piece of aluminum across the entire top. Bolts on either side to the swinging frame. Everything is wrapped in rubber cove base. Overkill BMS fastened with commercial velcro on top. I've helped a few others build batteries that fit their space. Most bang for buck. Bit more labor, but worth it in my opinion.
 
I bought qty#2 (EG4-LifePower4 Lithium Battery | 12V 400AH 5.12kWh | Server Rack Battery)(That would make 12V 10kWh) Server rack battery for Rv. Also, i bought Victron MultiPlus 3000VA. What do you guys think how long i can run my 30ft RV trailer.
 
The stored energy is about $1.50 worth of electricity so a/c may use it up in a day. If you don’t use the a/c and you have LED lighting, I’d guess a week. It sounds like a nice setup to me.
 
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