Does anybody here think 12 volt is the way to go for flexibility?

[Moretorque]

Just wondering, you can wire them into 48 and they are much easier to ship but harder to setup........ Thanks...

 

[DIYrich]

I go with the 3v cells myself.

 

[SparkyGage]

The smaller the project and more it requires it for logistics (and/or portability), yes. But as the project gets bigger, more permanent and more stationary, no. 1 48v 100Ah battery is probably just as cheap to purchase AND ship as 4 12v 100Ah batteries in most cases. Any number of factors can cause an exception to my rule (and your use case might be one of them) but if I want to end up 48v, I'm going straight to 48v most of the time.

Are you talking building your own packs or how to configure "finished" batteries?

 

[Moretorque]

The point was made to me if you have a problem with a 12 you can send it UPS where a 48 100 pounder you cannot so in that regard it is better they were claiming. You have a 12 laying around for standby and it one goes bad in your 48 4 12's wired up you can replace that section and easily ship the other out for warranty? Thanks for replying....

 

[SparkyGage]

The point was made to me if you have a problem with a 12 you can send it UPS where a 48 100 pounder you cannot so in that regard it is better they were claiming. You have a 12 laying around for standby and it one goes bad in your 48 4 12's wired up you can replace that section and easily ship the other out for warranty? Thanks for replying....

Then, yes, in that scenario, I wouldn't argue with that strategy. You would have other issues you will need to plan for and monitor (balancing), but I wouldn't call them a deal breaker. Particularly if the manufacturer is ok with using the batteries in series (as most that I've seen are). And in that scenario, I would probably rotate in the spare as a matter of routine - say ever 6 months.

 

[HarryN]

I always do it that way.

The one aspect that you do need to be careful of is that not all 12 volt batteries are rated to be wired in 24 or 48 volt, especially the cheap ones.

 

[Moretorque]

I always do it that way.

The one aspect that you do need to be careful of is that not all 12 volt batteries are rated to be wired in 24 or 48 volt, especially the cheap ones.

I know that, I steal all my ideas from other people. I should become a patent attorney I guess....

 

[45North]

Yes, 12v let's you use lots of standard stuff off-the-shelf from automotive and RV stores.
And for small systems that's all you need.

 

[David in nh]

just go 48v because in the end that's were you will end up anyhow

 

[mikefitz]

you can wire them into 48

Connecting 12v batteries in series, each with its own BMS, to create a higher voltage battery will eventually have balance issues. You can add battery ballancer hardware to help solve the issues, but its good engineering practice to have a 16 cell 48 volt battery with a single BMS .

 

[Moretorque]

Thanks...

 

[HarryN]

I know that, I steal all my ideas from other people. I should become a patent attorney I guess....

I was just encouraging you.

As far as batteries going out of balance - sure but if you buy a good quality battery then it will take a long time.

I have done this with Lifeline AGMs and Battle borns. If you take the time to really set them up in the beginning with good charging and tied together in parallel for a few days, so far they have stayed balanced for years.

 

[orangezero]

I don't know why so many continue to encourage fellow DIYers to buy costly, premade 12v packs and then link them all together in some way that is or isn't recommended by the manufacturer. Sidestep most of the issues discussed above by purchasing your own bms for whatever voltage you decide, along with much less expensive bare cells.

I didn't want to spend any more money or make things more complicated than they need to be. A bad cell will often be bad during the return window. I don't feel warranties are worth much, because I don't assume the company who sold them will be around in 4 or 8 years time.

 

[pollenface]

Just wondering, you can wire them into 48 and they are much easier to ship but harder to setup........ Thanks...

i don't follow what you mean by much easier to ship and harder to setup?

I use both 12v & 48v, each serves it's own purpose.

 

[JRH]

Connecting 12v batteries in series, each with its own BMS, to create a higher voltage battery will eventually have balance issues. You can add battery ballancer hardware to help solve the issues, but its good engineering practice to have a 16 cell 48 volt battery with a single BMS .

I agree with your answer as I have witnessed it with a friends system who has 4 batts in series each with a seperste BMS and at 48 volts… , he has balancing problems . Incant offer him much help as I have never had a 48v system...

but I have always wondered , does the more batts in series aggravated the balence issue…as in , does 4 in series cause more issues than 3 …or just 2 in series… or is it all the same regardless …

I’m sure it’s been addressed somewhere but I have never seen it discussed..

Thanks .J.

 

[Moretorque]

I don't know why so many continue to encourage fellow DIYers to buy costly, premade 12v packs and then link them all together in some way that is or isn't recommended by the manufacturer. Sidestep most of the issues discussed above by purchasing your own bms for whatever voltage you decide, along with much less expensive bare cells.

I didn't want to spend any more money or make things more complicated than they need to be. A bad cell will often be bad during the return window. I don't feel warranties are worth much, because I don't assume the company who sold them will be around in 4 or 8 years time.

Battery Hookup has a battery that consist of 4 12volt all tied together and it looks interesting is all. The 12 volt batteries are under 80 pounds so they can be shipped UPS.FEDX, regular mail?

 

[Rednecktek]

Does anybody here think 12 volt is the way to go for flexibility?​

Short answer?
No.

Long answer?

Nnnnnnnnnoooooooooooooo

12v has its uses and places, but limitations kick in quick once you're out of the van/camper/shed world. Putting batteries in series to get to 48v can save money on the front end, and adding in a balancer to reduce drift can just barely eek out the cost of a full 48v battery, but it's just barely. Add in the cost of wire and lugs and it's pretty much even or higher. About the only advantage to stringing 12v batteries together is moving them the first time.

Honestly though, once the batteries are in place and wired up, what are the odds you're going to undo all the wiring and move them? Beer and pizza is a MUCH better value at that point.

 

[HarryN]

This thread is a good example of the variety of experiences that people have with approaches to batteries.

There is more than 100 years of industrial use of batteries made up of various size cells in a variety of chemistries to make voltages from ~ 1 volt to 100s of volts - perhaps more.

There are proven successful, essentially negligible maintenance required batteries in use built up from 6, 12, 18, 24, 36 and 48 volt commercially made batteries into a wide range of voltages. Built from suppliers who do in fact agree that it is acceptable. ( obviously the cheap brands it will not work on )

And there are people who are convinced that the only good way to do it is to build their own battery from random imported cells and that this is somehow less labor and liability than just buying some good batteries in the first place and doing a proper charge / discharge cycle set.

I can't imagine suggesting to someone who is trying to get a modest size / beginner project done in a reasonable amount of time, that they should also go through the PITA to build their own battery from misc imported parts. Maybe project #3, but project #1 ?

 

[orangezero]

I found attaching busbars and bolts and nuts to be neither time consuming nor much of a PITA, which is how many bare cells are combined. It was way easier than the mental energy needed to design a system.

Someone who finds these things difficult would not typically want to diy a solar system in the first place, eh?

Building with bare cells saved me thousands of dollars and took my solar project from just an idea to reality. I can't say your advice would have been all that helpful early on in the process.

Choose your batteries and electronics wisely...

 

[Moretorque]

I found attaching busbars and bolts and nuts to be neither time consuming nor much of a PITA, which is how many bare cells are combined. It was way easier than the mental energy needed to design a system.

Someone who finds these things difficult would not typically want to diy a solar system in the first place, eh?

Building with bare cells saved me thousands of dollars and took my solar project from just an idea to reality. I can't say your advice would have been all that helpful early on in the process.

Choose your batteries and electronics wisely...

Thanks, that is why I need help. I will just spend the money and be done with it.