How to run 12 volt on 48 volt system?

[bgrieves1]

Hi. I am going to make a DIY system with Will's video.
EG4 3000 EHV
EG4 server rack battery

using the above components. To power an instant pot, a 12 volt crockpot, a 12 volt car fridge. This will go in my Toyota Prius.

So how do I run 12 volt stuff off this 48 volt system? How do I hook up a 48 volt to 12 volt converter to the above system.

I Greatly appreciate Will's or anyone else's help with this. Thank you

 

[zanydroid]

Probably involves distribution fusebox after your main fuse or other OCPD coming off the battery since the small fuses for the 12v circuits probably can't interrupt the full power of the battery.

What is driving the 48v requirement here? What is driving the desire to use a huge server rack? Feels like the reason is that you found a full design that contained both, which frankly isn't a good reason to go 48v nor server rack.

EDIT: Hopefully someone pops in here with a better starting system for what sounds like car camping in a small car.

EDIT2: You will need like a 500W 48V to 12V buck converter for the crock pot and car fridge. That sounds on the large side but I don't work with these systems. If you switch to an AC crock pot it would significantly shrink the buck converter you need.

Energy and Power audit is important here too. The main power user on your list is an instant pot and that takes a single 15A circuit. It uses a lot of juice when heating up. When it's maintaining pressure the power usage goes down significantly though the microcontroller still pulses up to 1kW to maintain pressure if I remember how mine behaves.

Is your Prius suspension going to be happy with a server rack battery in the trunk all the time? The audit will tell whether you need to haul around this mass and volume of battery.

 

[bgrieves1]

Well, we just need to power a small dometic car fridge, the instant pot and we have a couple of 12 volt roadpro things, like a small 12 volt crockpot and a 12 volt water heater. I suppose we could run those off the cigarette lighter although I prefer to leave the car system alone. Just picking this system because it looked good on the youtube vid. Dont know too much.

 

[bgrieves1]

Probably involves distribution fusebox after your main fuse or other OCPD coming off the battery since the small fuses for the 12v circuits probably can't interrupt the full power of the battery.

What is driving the 48v requirement here? What is driving the desire to use a huge server rack? Feels like the reason is that you found a full design that contained both, which frankly isn't a good reason to go 48v nor server rack.

EDIT: Hopefully someone pops in here with a better starting system for what sounds like car camping in a small car.

EDIT2: You will need like a 500W 48V to 12V buck converter for the crock pot and car fridge. That sounds on the large side but I don't work with these systems. If you switch to an AC crock pot it would significantly shrink the buck converter you need.

Energy and Power audit is important here too. The main power user on your list is an instant pot and that takes a single 15A circuit. It uses a lot of juice when heating up. When it's maintaining pressure the power usage goes down significantly though the microcontroller still pulses up to 1kW to maintain pressure if I remember how mine behaves.

Is your Prius suspension going to be happy with a server rack battery in the trunk all the time? The audit will tell whether you need to haul around this mass and volume of battery.

We also live in a cloudy place, so I thought a larger battery would store the power I get on a good day. Im thinking 100ah server rack would work. Will seems to love the server rack batteries. I can change on the 48volt, I just dont know what I am doing. This system looked easy and powerful

 

[bgrieves1]

Probably involves distribution fusebox after your main fuse or other OCPD coming off the battery since the small fuses for the 12v circuits probably can't interrupt the full power of the battery.

What is driving the 48v requirement here? What is driving the desire to use a huge server rack? Feels like the reason is that you found a full design that contained both, which frankly isn't a good reason to go 48v nor server rack.

EDIT: Hopefully someone pops in here with a better starting system for what sounds like car camping in a small car.

EDIT2: You will need like a 500W 48V to 12V buck converter for the crock pot and car fridge. That sounds on the large side but I don't work with these systems. If you switch to an AC crock pot it would significantly shrink the buck converter you need.

Energy and Power audit is important here too. The main power user on your list is an instant pot and that takes a single 15A circuit. It uses a lot of juice when heating up. When it's maintaining pressure the power usage goes down significantly though the microcontroller still pulses up to 1kW to maintain pressure if I remember how mine behaves.

Is your Prius suspension going to be happy with a server rack battery in the trunk all the time? The audit will tell whether you need to haul around this mass and volume of battery.

Here is another system that I found on Will 's website:​

this is only 1kw. I would think I need at least 2kw. I will look at MPP products

​

​

Parts List:​

1. MPP 12V 1kW Model:
   Click Here to purchase
2. 100-400+ amp hours of 12v Batteries:
   12v Lithium Batteries (choose one with low temp cut off!) Click Here
   
   12v Lead Acid batteries Click Here
3. 200-500 watts of Solar Panels
   Click Here
4. 6 gauge wire kit (Battery to MPP)
   Click Here
5. Solar Panel Array to MPP Wires
   Click Here
6. 12 gauge AC Extension Cable for AC Input/Output (needs to be cut and stripped to install into mpp solar box)
   Click Here

 

[SamDeleted]

We also live in a cloudy place, so I thought a larger battery would store the power I get on a good day. Im thinking 100ah server rack would work. Will seems to love the server rack batteries. I can change on the 48volt, I just dont know what I am doing. This system looked easy and powerful

Victron Orion-Tr 48/12-30A (360W) Isolated DC-DC converter - ORI481240

The converter steps down the voltage from a 48V battery bank to 12V, for feeding low-power 12V loads up to 360Watt Remote on-offThe remote on-off eliminates the need for a high-current switch in the input wiring. The remote on-off can be operated with a low-power switch or by for example the...

voltaconsolar.com

Surely your best option is a 48v - 12v converter?

Trouble is they are expensive and slow (360w) If I remember correctly these can be used to charge a battery, I'd use a cheap lead acid , car or deep cycle if possible

So system would go:

48v rack battery > fuses > victron Orion-tr 48/12 > lead battery (12v) > fuses > 12v loads

 

[Rednecktek]

So back to the earlier question, but why 48v? There isn't a converter out there cheaper than your car that can handle what a 48v rackmount can put out.

Get (or build) a nice sized 12v based system and call it a day!

It might help if you threw together a list for us of what you're trying to run, or even better yet did a proper power audit. Example:

MargaritaMaster-9000 120v 15a
MargaritaMaster-Mini 12v 5a

Going to a 2Kw system rules out using a 12v AIO and you have to step up to 24v at least and find a honkin huge DC-DC converter. The biggest I've seen are about 60a max @ 12v out.

You're local (I'm near the airport), so if you did want to build a battery and bought the parts we could get together and have a class. I'll bring tools even.

 

[Rednecktek]

We also live in a cloudy place, so I thought a larger battery would store the power I get on a good day. Im thinking 100ah server rack would work. Will seems to love the server rack batteries. I can change on the 48volt, I just dont know what I am doing. This system looked easy and powerful

Easy? Yes. Overpowered for your needs? Yes. Additional complications involved? Yes. Filling ALL the space in your Prius? Yes.

There are about 10 bazillion ways to build a solar system, but 9.9999999999 Bazillion of those ways will be wrong for your needs. Every system is different slightly for a reason.

 

[tghowe]

This...

https://www.amazon.com/dp/B08LDBJC1K/?coliid=I3546JVK5FS9OF&colid=UAK5AC900Q8R&ref_=list_c_wl_lv_ov_lig_dp_it&th=1

 

[Jim in Florida]

Just a thought, IF you are only using 12v equipment why not get the same size battery in 12v? Assuming you have not already purchased.
12v 400 amp has the same energy as 48v 100 amp. Each time you convert from one voltage to another there is a energy tax for each transaction (your battery pays that one). Lots of van life equipment out there.

 

[Rednecktek]

And 12v parts are at nearly every auto parts store.

 

[zanydroid]

To power an instant pot, a 12 volt crockpot, a 12 volt car fridge. This will go in my Toyota Prius.

Can you paste the electrical requirements of each appliance? Or at least the product page. The estimates of your power requirements by folks on the thread are all over the place.

The instant pot may end up being difficult for a 12V system, so if there's an alternative (maybe in vanlife appliances) that could make your life easier.

Also missing is the energy requirements or description of lifestyle from which this can be calculated. It's unclear how you will deploy solar panels from this small vehicle.

Another approach to figuring this out is to start with a example Prius build off YouTube or a forum. Vs starting from low knowledge and trying to learn both solar and how to cram it in

 

[bgrieves1]

Victron Orion-Tr 48/12-30A (360W) Isolated DC-DC converter - ORI481240

The converter steps down the voltage from a 48V battery bank to 12V, for feeding low-power 12V loads up to 360Watt Remote on-offThe remote on-off eliminates the need for a high-current switch in the input wiring. The remote on-off can be operated with a low-power switch or by for example the...

voltaconsolar.com

Surely your best option is a 48v - 12v converter?

Trouble is they are expensive and slow (360w) If I remember correctly these can be used to charge a battery, I'd use a cheap lead acid , car or deep cycle if possible

So system would go:

48v rack battery > fuses > victron Orion-tr 48/12 > lead battery (12v) > fuses > 12v loads

 

[bgrieves1]

Thank you so much. I will study this

 

[bgrieves1]

So back to the earlier question, but why 48v? There isn't a converter out there cheaper than your car that can handle what a 48v rackmount can put out.

Get (or build) a nice sized 12v based system and call it a day!

It might help if you threw together a list for us of what you're trying to run, or even better yet did a proper power audit. Example:

MargaritaMaster-9000 120v 15a
MargaritaMaster-Mini 12v 5a

Going to a 2Kw system rules out using a 12v AIO and you have to step up to 24v at least and find a honkin huge DC-DC converter. The biggest I've seen are about 60a max @ 12v out.

You're local (I'm near the airport), so if you did want to build a battery and bought the parts we could get together and have a class. I'll bring tools even.

Thank you for your generosity--do you know where I live? Im shy about telling the world where I live. Is there something on my profile that tells you where I live?

 

[bgrieves1]

So back to the earlier question, but why 48v? There isn't a converter out there cheaper than your car that can handle what a 48v rackmount can put out.

Get (or build) a nice sized 12v based system and call it a day!

It might help if you threw together a list for us of what you're trying to run, or even better yet did a proper power audit. Example:

MargaritaMaster-9000 120v 15a
MargaritaMaster-Mini 12v 5a

Going to a 2Kw system rules out using a 12v AIO and you have to step up to 24v at least and find a honkin huge DC-DC converter. The biggest I've seen are about 60a max @ 12v out.

You're local (I'm near the airport), so if you did want to build a battery and bought the parts we could get together and have a class. I'll bring tools even.

I guess I need to learn to do a proper power audit. I will study this when I get time. Small dometic 12 volt car fridge, instant pot, some 12 volt things.

 

[bgrieves1]

Thank you for your generosity--do you know where I live? Im shy about telling the world where I live. Is there something on my profile that tells you where I live?

Well...duh.....I just clicked on my profile. Says Seattle right there. Well, no hiding now!

 

[bgrieves1]

Can you paste the electrical requirements of each appliance? Or at least the product page. The estimates of your power requirements by folks on the thread are all over the place.

The instant pot may end up being difficult for a 12V system, so if there's an alternative (maybe in vanlife appliances) that could make your life easier.

Also missing is the energy requirements or description of lifestyle from which this can be calculated. It's unclear how you will deploy solar panels from this small vehicle.

Another approach to figuring this out is to start with a example Prius build off YouTube or a forum. Vs starting from low knowledge and trying to learn both solar and how to cram it in

Thank you. The Prius you tubes want to pull off of the car batteries. We prefer to leave our car batteries alone. Ive been studying portable foldable solar panels--Ecoflow looks good. Plan to get 2--put one in front windshield and another in back under hatchback window. We are planning to live out of our Prius in 7 weeks. We can alternate this with Airbnb when we get burnt out. We work a lot so just need a place to sleep and eat a little.

 

[bgrieves1]

Just a thought, IF you are only using 12v equipment why not get the same size battery in 12v? Assuming you have not already purchased.
12v 400 amp has the same energy as 48v 100 amp. Each time you convert from one voltage to another there is a energy tax for each transaction (your battery pays that one). Lots of van life equipment out there.

TY so much. 12v 400 amp has the same energy as 48v 100 amp. Looks like a 12 volt system would be better than 48v.
12v 400 amp has the same energy as 48v 100 amp.
Good to know!

 

[Rednecktek]

Thank you for your generosity--do you know where I live? Im shy about telling the world where I live. Is there something on my profile that tells you where I live?

?

I guess I need to learn to do a proper power audit. I will study this when I get time. Small dometic 12 volt car fridge, instant pot, some 12 volt things.

That Instapot is going to be the big power draw most likely, spec your inverter for whatever that is going to be drawing. There should be a sticker or plate on the bottom that tells you what the voltage and amps are for it. The fridge is usually a huge energy hog too.

Plan to get 2--put one in front windshield and another in back under hatchback window.

The windows have a UV coating on them that is going to make panels useless, you'll need to plan on sticking them outside of the windows.

TY so much. 12v 400 amp has the same energy as 48v 100 amp. Looks like a 12 volt system would be better than 48v.
12v 400 amp has the same energy as 48v 100 amp.

It's all about the watts. Watts = Volts * Amps so 100a at 48v = 200a at 24v = 400a at 12v = 480v at 10v and so on.

 

[Jim in Florida]

TY so much. 12v 400 amp has the same energy as 48v 100 amp. Looks like a 12 volt system would be better than 48v.
12v 400 amp has the same energy as 48v 100 amp.
Good to know!

You are welcome, take your time on your project, know what you need and how to do it safely.
There is enough energy in these batteries that if done incorrectly can burn down your project or possible kill someone. It’s easy to spend money fast, just make sure it’s the right solution for you.
There are several YouTube vids out there with similar projects. I even saw one that converted a bike rack to hold solar panels to charge the EV it was attached to.

 

[zanydroid]

The fridge is usually a huge energy hog too.

I think car fridges are specced to stay under 12V * 10A so they can be plugged into a accessory port and not blow fuses or overload the alternator? IE the power will not be the critical path.

But it will probably be the biggest energy hog out of these appliances.

Plan to get 2--put one in front windshield and another in back under hatchback window.

How many watts of panels is that and expected hours of sun? Did you use PVwatts website to do a sanity check, by entering the orientation info and panel wattage + location?

Do you have a backup plan or scale up plan if something goes wrong with the design and you can't feed the critical appliances as needed?

 

[bgrieves1]

Yeah. Grocery store, drive thru. We are in a fairly big city so grocery stores are easy to get to. Ive always been good at finding food

 

[Rednecktek]

I think car fridges are specced to stay under 12V * 10A so they can be plugged into a accessory port and not blow fuses or overload the alternator? IE the power will not be the critical path.

Yes, but they tend to run all the time which eats up a lot of battery over time. It's a capacity and recharging thing more than a huge-wire-big-fuse thing.

 

[zanydroid]

Yes, but they tend to run all the time which eats up a lot of battery over time. It's a capacity and recharging thing more than a huge-wire-big-fuse thing.

Ok. So it will dictate battery, solar panels, and potentially charging from shore power, but if EG it becomes better to go to 24v for the instant pot then the buck converter does not need to be so big.