I tell people this all the time but they still buy 12V batteries. I don't get it. Then they argue with me about how they like 12V and none of the reasons are compelling. I've done endless all in one one/converter/48V battery videos, but people still choose 12V. It's nuts.
I was searching through various sources of batteries and found CMX/COREMAX Batt. The site makes some claims that look like they are the OEM manufacturer of several different brands, including RoyPow and EG4.
Are you going to tear one of these Power Queen batteries down, Will? Will be interesting to see your take on them also. Looks like a similar manufacturer to other 48v server rack batteries (SOK perhaps?).
Just going to throw this in. 48v inverters tend to be larger and hence cost more money and burn more power idling. My own advice to anyone starting out is to go straight to 24v system and get two identical batteries at 24v at the same time so that they degrade equivalently. Buy prebuilt new or build your own. After a year or two you can slowly upgrade and you will ready to engineer a larger system that is right for you. One nice thing about this option is you can always split it up later to have the original batteries serve power to separate locations or equipment. Off-grid isn't that complicated in the end. Hardest thing to understand is wire gauges and lengths. If you have lots of land/space then buy used panels vs the latest and greatest and you will save money and get more power.
Splitting it up only increases the costs. You can find smaller 48V inverters and charge controllers now. Secondly splitting it up increases the inefficiency. You have the added loses of a second setup, where as if you just move the power through the AC infrastructure is more efficient. It doesn't matter if a bigger setup is 10% less efficient because if you added the inefficiency of two smaller systems, it would be more than the larger one.
@@davefroman4700 I was describing someone starting out with solar. If you buy 16 cells you can have two 24v batteries in parallel. Yet you can still move to 48v later and double or quadruple the cells. In the beginning no one really knows what they want/need until they get their hands dirty. 24v is a cheaper and slightly less intimidating just getting into it while being able to convert your battery setup later once you grasp how much power each thing uses. For my setup I run as much as I can DC to DC. Yes there are smaller 48v inverters but not everyone knows how much power they use or want to use. 48v inverters are thousands of dollars. Off grid is a being mindful of what power your using and when. People starting out at say a 5k 24v system will gain the confidence and a couple years later buy 30k of batteries in a 48v config knowing it's a solid investment.
The Power Queen I referenced in this video is the 51.2V (48V), 90Ah, 4.6kWh (currently out of stock). Here is a link for your reference: ipowerqueen.com/products/power-queen-51-2v-90ah-lifepo4-battery-built-in-90a-bms?ref=gwq9cs98 It is $1,199.99 including shipping. With my discount code, you can get an additional 3% OFF Site Wide CODE: Everyday3 $1,200/4,600Wh=$0.26/Wh The EG4-LifePower4 51.2V (48V) 100Ah, 5.12kWh battery is $1,499 plus shipping (Apparently $1653 to your location). Here is a link for the one I am referencing: signaturesolar.com/eg4-lifepower4-lithium-battery-48v-100ah/?ref=SALE $1,499/5,120Wh=$0.29/Wh Now, the EG4 version has more features and may well be worth the extra cost, but the Power Queen is still the lower cost option. Hope that helps.
@@ProjectsWithDaveLooks like they never actually bothered to make the server rack batteries as a year later and they're no where to be seen on Power Queen's website.
I have all powerqueen batts in my systems, and have been looking at these closely for a small backup system for a separate off-grid system to use to power my Garage mini-split, and charge our Ford Lightning. I want to build a 48v system, at least once for practice for an eventual system we'll build in Panama. I'm at the age that the microscope is a huge find. Thanks!
Hello Dave, Thanks for clear, well paced video and the content. I just signed up to your channel because I can see you have a sense of respect and willingness to help viewers who do not have experience in working with solar panels. I have wathced some videos on a youtube channel where the person was laughing at the viewers by fast forwarding his video and speaking intentionally faster and showing some formulas that dissappear before you can read them.
You could also get the power queen 300ah 12v battery which has a 200a BMS. I agree about expandability though. If you want something REALLY powerful then higher voltage makes sense. Imagine trying to run a normal electric dryer off the grid. I think that’s about 5000w at full power. There are probably people that need 5-10kw of capacity. There are also larger buildings and workshops. Solar could definitely handle all that but you would need some crazy batteries
Very nice video. Fun custom stuff that is diy friendly. I think they make converters that can output 13.5v instead of 12v. Or there are step down converters that you can set a custom voltage.
I agree, that is a much better choice. I found the converter you mentioned and updated the schematic and parts lists to include that version. You can see the updates on my website: projectswithdave.com/48v-to-12v-dc-dc-converter-project-build/
@@whochecksthis I have one of those 13.8V boost-buck coverters. A full 6 cell Lead Acid battery is 12.8, and 13.8 when float charging.. 12V automotive equipment works best between 12.6 and 14.4V. As you se in the video, the battery protection circuit activated in the fridge...
With respect to Prowse and others, using 12v batteries as the base power source gives you more flexibility when stuff goes to hell. Worse case scenarios, you can gather abandoned 12v car batteries and build whatever sized system you need or are equipped for. The MPPT can be and should be a multi-voltage device. I use 24v and 12v batteries from 100ah to 200ah, but I SPd/S them to only 24v systems. Solar panel deployment space is one compelling reason for my setups. I cannot use more than 6 panels (200w) total with 3 in one area, and 3 in another area on my property/rental. HOA!
I too have stuck with 12v because I rent and most of my system is installed in my off road vehicle which I seldom drive having a second vehicle for everyday use. When I'm at home I power most of my house appliances with the aid of additional solar on my shed which I connect to the system in my vehicle. When I'm away from home the only thing I really need to power at home potentially from the grid is refrigeration. I will eventually make a small fixed system at home dedicated to that when I'm away. I prefer to take the power I produce with me. If I move or SHTF I don't want to have to dismantle and reassemble a system, or worse case abandon it.
I would get the 60 amp converter for 12 volt loads because alot of products won't run if the voltage sags that low..Like compression fridges, etc. Wrote that b4 you got to the fridge, but it's true with many fridges..But, yes 48 volt systems are the way to go, especially with the all in one inverter/solar charge controller/ ac charger like EG4/MPP/Grow watt..The little EG4 3000 watt all in one can handle 5,000 watts of solar, allowing for expansion..Expanding battery capacity is tricky, you don't want to wait too long..A separate premade solar generator for 12 volt loads, can make sense also, plug it into the inverter and charge with solar, and the DC side will be efficient and mobile..
Another excellent video, as per your usual standards. For an off-grid home, or even a larger cabin or class A motorhome, the 48v system you built and the 12v accessory panel would make a lot of sense. For vanlife builds, most marine applications, or small off-grid applications, 12v and 24v builds probably make more sense.
@@ProjectsWithDave - Yes, many of the applications I mentioned are designed to run off of 12v or 24v batteries. Converting lower voltages to 110/220, just to power small loads that don't draw many amps isn't very efficient. Many products ulimately use a lower voltage to run, so it's more efficient if you supply that voltage directly.
We have a remote cabin that has an old Trace 4048. I’ve been using it close to 20 years. I’m still using 12v agm batteries in series that I put in back then. I always tell people about high current loads and internal resistance in batteries. I worked in telecommunications for many years and most equipment was 48v. I worked one place where the cells were 1700ah. They weighed close to 700 lbs for each 2v cell.
@@jasonbroom7147 We have a remote cabin with a 48v system for an inverter and also a 12v system for RV pump and H2O heater electronic ignition. Also all the lights are 12V Led.
Great video... you should try a Renogy 20-40-60 amp DC - DC converter. Victron also has some, but they are VERY expensive. The Renogy's are reasonably priced and would hold voltage under load.
While I don't have any empirical data for that, I think it would be no problem. The construction is well done. The case is solid steel, the batteries are held in place with steel U channel the BMS is bolted securely and all the wiring is secured well.
As Dave has said, these batteries are very robust and dont really get hot, but you would be advised to plan for some sort of ventilation in most battery and charging areas anyhow. In a larger RV/Motorhome/van they would an excellent choice if u have the realestate for enough solar panels to get ur voltage up high enough to operate a higher voltage MPPT AIO system. I have a 24v 3kwh AIO system in a stationary 40’ Bus on a property up north that works well, but I was considering a 48v 5 kwh system. I have 10kwh in 2 x 24v batteries I constructed with JK BMS’s. The bus is already a 24v system was probly the main reason for going the 24v route for me, but I do have a 48v system I also built for my house that works well too, it has 30 kwh of Lifepo4 made up of 3 of these sever rack type & a 15kwh battery I made with EVE type cells and another JK BMS, all in parallel, a 5 kwh MPPT AIO system, 10 kwh of solar grid tie pv. I charge the batteries by day timer for 6 hrs via a gpo and the AIO system, this runs most of my house and only uses about 15%-25% of the batteries capacity for 18hrs of use each day & I get about $30-$50 / month from my power company for the excess solar.
Yeah good job Dave, 48vdc is the new 12v/24v for most power hungry usages, homes, large RV’s etc. Main considerations for RV or van installations is weather u have the real estate if u want to use solar panels to get the voltage above 60v for charging purposes, but there a generally ways to do this. Cheers
Most are even 120v minimum input. That growatt P model is the only one I can find for 60v. Do you know of any others, or have suggestions if I'm only running 2-4 solar panels?
I am struggling between 24V and 48V for our sailing catamaran. It is the solar panels that are pushing me to 24V. I really want an individual controller on each panel so I have the best power generation when the rig is shadowing a panel or two. The panels are 585W 44V each so I'd have to put two in series to get past 48V. The big draw on the boat are winches, windlass, and tender lift - all 12V. It is impractical to provide 12V@200A continuous from a 48V-12V converter or 24-12V converter so I'll need a 12V battery that can deliver that load. The house bank (24 or 48V) will not have any native loads beyond the dual 5K inverters except for maybe DC aricon in the future (currently 220VAC). I've been looking at the Epoch 12V-460Ah in a 2S2P configuration allowing redundancy and an additional 12V-460 for the 12V native loads. 24V seems easier to get back to 12V and with the solar panel voltage, I think I'm leaning towards 24V.
After 3 years when this 48 volt rack comes up with a malfunction of a small component the whole system comes crashing .on the other hand if the 12 volt lithium batteries are linked together with BMS on sides of the bank it would be easy to fix quick .
Many factories here (I live in Shenzhen) use that DC/DC case but the circuits inside vary widely. That's a pretty steep voltage sag on the output if that's not from a long wire loss at high current.
I am setting up another network tower but this time at a remote location I was researching on the solar power that is when your channel popped up, you are helpful Sir, hello from Nairobi Kenya, Africa
Link to detailed project breakdown: projectswithdave.com/48v-to-12v-dc-dc-converter-project-build/ Link for circuit diagrams and materials: drive.google.com/file/d/1TUxY7vWT-FdzB3GTjwNdMUEjv9KE3Dgs/view?usp=sharing Update: I ran the 12V power test again using 12 AWG conductors. At 153W, I had 11.4V and 13.4A, the input was 166W. 92% efficient. Much better result.
I suggest that the high lost of voltage on 12v car adapter to something around 9 volts when drawing 16 amps, is due to a connector which is rated to 10 amps max and very small wires guage. A quick mesurement at the closest point of the dc-dc converter would probably showing pretty closed to 12v, and maybe the reason why the converter stayed cold.
It looks like the cables at the 12v test running 16A are quite long and thin plus not unwinded. This could explain the low voltage especially since voltage drops more over time due to heat in the cable.
Yes, I think you're right. I need to re run the test with shorter 12awg cables. Update: I ran the test again using 12 AWG conductors. At 153W, I had 11.4V and 13.4A, the input was 166W. 92% efficient. Much better result.
yea not the cheapest per watt. you can get 100AH batteries at 1200 for a 100AH battery. So that statement is not longer true. You can get 304AH for $1700 now.
I was thinking that might be the problem as well. I ran 12awg to the socket, however the wire for the test circuit was smaller. I might try it again with 12awg the whole way.
If you’re running mostly 12v appliances then why choose 48v and loss efficiency on your buck converter? The real killer for 12v is the solar chargers on the market for 12v (say victrons’ smart solar chargers) are around $600 per 1kw of solar input, whereas 48v is 4kw per $600.. If you’re never going to expand your solar array then it would be fine.
If everything you are powering is 12V it makes sense to run a 12V system. Otherwise, as you said, you can get more power for the same money on the charger and inverter side.
You can get a server rack version of those 12v batteries, all the benefits of extra wire management, but just one 200amp inline fuse, 12V 6144Wh LiFePO4 Battery Built-in 250A BMS
I will be using a 48V system for my larger systems on my property. I have used 12 volt inverters for smaller systems because I haven't wanted to invest for small systems and most of my radio equipment is 12 volt, but with the buck converter, it makes more sense to have a 48 volt system. Or what i could do, is do a 48 volt system and use an ac to dc power supply for my 12 volt stuff.
Personally I would go with a 48 to 24V converter because a lot of 12V appliences also run on 24V and it makes doing long runs eaiser and the 48 to 24V get you more power for the same price as what causes the unit to heat up is the amperage not the voltage. For anything that needs any other voltage than 24VDC or 230VAC I would just run 48 volts to it and have a small DC to DC converter for it in situ like my 5G modem for example which only need 12V 3A and you can get a multipack of veriable voltage 3A down converter for like $15, and also maybe lights, although you can get 48V and 24V LEDs, I would probably want the LED to be votlage regulated so I would probably buy 24V LEDs and obviously run them off the 24V converter. And yeh 12V 3A is overkill for a 5G modem, it's just the plug it comes with it never actually consumes anywhere near that amount of power.
I don't understand why you would need 4 batteries when you can buy a single battery that is 12v @ 400 amps just like you can buy a single battery that is 48v @ 100 amps.
Me a month ago: “ oh my rv came with 1 solar panel and 4 6volt agm batteries so I’m gonna stay on 12 volt” Me: 1 week ago “goddamnit. Shoulda went 48v… fuck.”
So I’ve done the same thing. I have two lp4 server rack batteries I have a 12v rooftop Air conditioner. I had a single step down converter. The AC requires 960 w the step down can supply 840. So it gets hot, I wanted to wire in a second step down converter to share the load. I had it all working for 3 months now. Until I added the second step down converter. I made the mistake of having two different kinds of step down converters one shorted out. I now have two the same. However after trying to wire them in parallel my AC won’t work. Could you do a video showing how to wire step down converter in parallel Or series? Currently I’m doing some troubleshooting to see if my original step down is shorted. Or if I fried my AC .
Maybe try a multimeter on the buck converter output to complement the load testers voltage reading at those somewhat high amp loads... That wire on the 12v jack looks quite thin, so I think you're probably losing 1 volt just in the wire resistance.
I am having hard time to find 3 to 1 T connector for 8awg wires. Since I already have 50 feet of 8awg wires I would like to connect 3 panels in parallel. There is 8awg single wire connector available wich can connect 10 awg and 8awg wires but there is no 3 t0 1 T connector on amazon and ebay. What can you recommend as a work around to this issue?
If you are trying to combine different size conductors I would make a small junction box and use the Dinkle Assembly Kit DK10N. You can use it as a combiner or passthrough. You can find it on my components page on my website here: projectswithdave.com/components/ Or on Amazon here: amzn.to/450gPQg You can see how I used it in my system here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-uS8cqppAy7s.html
I built a DIY 48V off grid system precisely because of the lower losses, from raw 100Ah LiFePo4 cells and individual electronic components, DIY BMS (incl. datalogger for each cell), DIY MPPT (98% eff), only the 230V inverter was off the shelf (I'm not messing with high voltage (yet)). 48V was the sweetspot for efficiency vs safety (I can touch the battery without much happening, sometimes it tingles a little, but no more; also simple fuses are still available at reasonable prices). 48V is also a voltage that is still reasonably low so DIY voltage converters are still quite simple to build. All that with no chinesium parts (they all actually provide what's on the label). Next step for my future projects could be high voltage DC (300ish V). Many 230V AC devices can also directly be powered by 300ish V DC, which would eliminate the inverter (and its losses). But for that to be viable it would have to be a much larger scale (30+ kWh battery). And I would need to figure out how to use high voltage DC safely (need different fuses etc.)
Nice details in your video. We've seen people use the 48/12V Buck Converters in RV's hoping to supply 12V to their loads like slide-outs. Unfortunately the output on those are unregulated. Nice to see you pointing this out.
@@ProjectsWithDave Same here, I guess it's the way my brain is wired. Assume it could be wrong and double check everything. I also mark all my DC stuff Red and black too.
When I worked for a government contract electronics company. If we needed a tool. We would walk across the street to Klein Electronics and put it on the tap or pay out of pocket.
Well, I agree with you for the 48v system but you should never feed a 12v fridge for just 12v cause the 12v system is just over 12.6v and can go as high as 14.5v depending on the battery type. Feeding it 12v regulated power will cause stress to that expensive refrigerator and not to mention that a cheap Amazon eBay buck converter will produce heat and potential power loss. Using the word " suck " for the 12v system will be ideal when you install a larger offgrid home but for campervan and small houses 12v system is the most cost effective option ever. Not to mention the batteries are also expensive compared to the panels and converter. Next time you use the word " suck " be sure to tag your title with what you're referring to.
In my wiring diagram and referenced material list I now include a 13.8V version that works better: projectswithdave.com/48v-to-12v-dc-dc-converter-project-build/
The Power Queen I referenced in this video is the 51.2V (48V), 90Ah, 4.6kWh (currently out of stock). Here is a link for your reference: ipowerqueen.com/products/power-queen-51-2v-90ah-lifepo4-battery-built-in-90a-bms?ref=gwq9cs98 It is $1,199.99 including shipping. With my discount code, you can get an additional 3% OFF Site Wide CODE: Everyday3 $1,200/4,600Wh=$0.26/Wh The EG4-LifePower4 51.2V (48V) 100Ah, 5.12kWh battery is $1,499 plus shipping (Apparently $1653 to your location). Here is a link for the one I am referencing: signaturesolar.com/eg4-lifepower4-lithium-battery-48v-100ah/?ref=SALE $1,499/5,120Wh=$0.29/Wh Now, the EG4 version has more features and may well be worth the extra cost, but the Power Queen is still the lower cost option. Hope that helps.
Why not go to high voltage batteries. 600 to 800 volts DC from the 25 kW PV. Battery is 600 VDC 160 LiFePO4 batteries.. 20 kW 3 phase hybrid inverter. I have the option of on or off-grid. High voltages while dangerous if not installed well has a much higher efficiency.
The nice thing about 48V is it is below the threshold where electric shock is less likely to be fatal. If efficiency is your main concern, than yes higher voltage is better.
So there is 30% conversion loss to power your 12v device from 48v battery. Doesn't seem that the 12v sucks, you can send up to 20 amps down 12awg wire, you didn't need to lose the 50w of power to do that, might as well have powered an inverter and connected 12v dc power bricks at that conversion loss! Who powers a heaterg un the whole day anyway? What my point to say is that some people that want compatibility with their low voltage devices without the conversion loss might as well have 12v DC systems.
I have a 48 V system already installed in my house. I’m wondering if you could do a video on two different battery bank brands hooked to a 48 V system. I’m wondering about the complications since your parameters have to be the same? 🖖 Doesn’t seem like there’s any videos out there on the subject, except Will Prowse, who doesn’t go into detail about how to do it. The last thing I want to do is destroy a battery bank.
Well, I'll have the materials to do that. I'll think about doing some analysis on the topic. However, It would be next fall before I was able to get to it. I'm pretty backed up with projects.
Great video/info. Is this the same principle used in major grid systems to send a million or so volts down a relatively smaller gauge cable and then step the voltage down as needed for distribution?
I have a 6k sunny boy inverter, it has 18 panels on it with 2 feed circuits, it is clipping in the middle of day, would it better to use the 3rd feed circuit and break the panels to 6 per feed in circuit
Clipping is a result of not taking advantage of all the available current. Generally speaking you will get the best performance at the highest voltage, which would be the most panels you can fit in a string but still leaving margin to the max input voltage. Do not exceed the max input voltage. It is possible to get more power by breaking your system into three strings if the inverter has a max power limit for each input. If it is clipping at 6kW that's the most you can get out of that inverter in any configuration. Breaking the array up into more strings does not reduce the current, it reduces the voltage. I believe your inputs have a 10A current limit. If your panels are rated for more then 10A you will always have clipping no matter the configuration.
It seem like an unnecessary mid point. You don't have the advantages of 12V power and the reduction in current is not nearly as significant as the 48V system.
@@ProjectsWithDave wanting to run dc compressor with USB feed to get ride of Cluny 12v cigarette lighter connection that tends to break quickly and is hard to keep connected while moving fridge around.
Thank you for the content! I’ve never heard of XT-60 connectors before, they look cost-effective! Do you have any other recommendations for general-use, cost-effective connectors?/do you use these often?
They are a very common connector in the hobby industry for batteries. They come in multiple sizes, this size is good for up to 60A. Here's a link: amzn.to/40H0JJj
Fantastic video. You intrigued me with monitor system. Please do video with whatever you monitor with. At present I'm doing Vue with Home assistant. One other thot is why 48v when 350v is available?
48V is the NEC's cut off for what's considered "low voltage", and generally it's safer to work with than the higher voltage stuff. Data centers and the telecommunications industry all run off of 48V DC and have been for years. And when you get up in the 300-400V+ range you need specialized equipment, training and tools definitely not something for the faint of heart!
Another good reason to run off 48vdc instead of using the inverter or grid power is the power efficiency (no wasted high inverter idle current) & redundancy backup if ur inverter shits itself u can still have lights, etc. Many of ur larger home LED panel lights will run between 40v-55v and can be wired with a cheap pwm dimmer control direct to battery, so their wattage can be controlled from a few watts up to 50w-60w for more conservative power control & good lighting.
I do have an adjustable version. I can set it to whatever output voltage I want. However, it seemed a little too complex for this video and it's a bit more expensive.
I have 48 volt systems for my home, rv and ebike. My frustration is the 48vdc to 12vdc converter. I looked into using a converter with an ebike battery for a trolling motor. Converters with a reasonable amperage and consistent voltage output are expensive! (I.e. automotive grade) Has anyone found something that works well at a reasonable price?
I'm about to purchase one of them Victron Multiplus's. Guess I will switch over to 48v. I already have 4 BB 100Ah lithiums.. Just need to find someone to wire it up.
My Victron works great, you won't be disappointed. For sure go with 48V. They now have a UL listed version ( www.currentconnected.com/product/pmp482305102/?ref=pwd ) . Also, if you purchase it through current connected they double the warranty.
@@ProjectsWithDave I've been on a road trip.. but am in Reno now. Am picking up my Multiplus in the morning. I think I have found someone that can wire it up.
There is not enough information to answer that question. If you connect mismatched panels in series, the voltages will add, and the current will be limited to the lowest of the three. As long as your inverter can handle the input voltage, it will most likely perform like three 100W panels. If your inverter has multiple MPPT's and is sensitive to low voltages, you could make two separate strings to maximize the output.
@@ProjectsWithDave thanks Dave. I made an error. It’s not the inverter but the contrôler that is in question. I haven’t checked the inverter yet. The contrôler is made for 300 watts. Will the mix harm it ?
@@ProjectsWithDave after a lot of research I found out that my 165W panel is a Furrion FSFP16MW-BL. They sell it with the right cable connectors that are different than the MC4 and they don’t sell the connectors or cable extensions. Such BS is hard to understand. They will sell me a solar panel 165W for $830. Ça n you believe this ? They also state that their panels work only in series and two of them connected in series will work with my Furrion 300W solar charger. They really set me up. Any suggestions for a cheaper way around this ? I think I have no choice but to get their panel and be done with it.
Why anyone would spend $830 for a 165W panel is beyond me. If you want, you can put your own MC4 connectors on the panel. Here is a complete kit: amzn.to/3TUuhAt Here is a video showing how to do it: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-oH3LqTu4B8E.html Here is a 180W quality panel, I've tested with good results for only $170 with the current $20 coupon: amzn.to/3U5cfw3 Looks like your maximum input voltage is only 70V so that does not allow for very many panels in series.
12v is nice for single battery portable systems. I like having the ability to run small 12v electronics directly without an inverter. I wish there were electronics that run on 48v directly
There will be in the future, thanks to EV's. Tesla is moving to the 48V architecture for their low voltage systems. Strictly for the efficiency gains. And with the Cybertruck coming out later this year is going to be the first to incorporate it.
@@jussikankinen9409 It all depends on what one is running more often.If i can run 12volt appliances with no conversion i save on inverter losses.Build a 12volt system with higher output bms and larger awg i still can have my cake and eat it to.More upfront cost but depending on appliances the 12volt system is safer and actually more efficient in some cases.
