Who is still building DIY batteries

[OffGridForGood]

A lot of sizes available from SWAG - I see a nice 30" finger brake that would work in my press with two x30 ton...
{darn you, I was trying not to spend money!}

 

[timselectric]

I'm a low level metal fabricator.
Sheet stock and angle iron. lol

 

[Dave911]

A lot of sizes available from SWAG - I see a nice 30" finger brake that would work in my press with two x30 ton...
{darn you, I was trying not to spend money!}

As a tool junkie, ya gotta get a fix periodically!
Im upgrading a mig welder I have to a double pulse unit for aluminum work inside and outside. Its a very interesting process. Way beyond a normal mig welder. It never stops!

 

[Zwy]

A lot of sizes available from SWAG - I see a nice 30" finger brake that would work in my press with two x30 ton...
{darn you, I was trying not to spend money!}

Just think of the battery boxes you could make, it would allow you to build a battery bank bigger than Tim.

 

[JJJJ]

think of the battery boxes you could make, it would allow you to build a battery bank bigger than Tim.

Who could lift it?

 

[42OhmsPA]

Threw this together quick while I sit in another pointless meeting, might be helpful.

 

[Danke]

Just think of the battery boxes you could make, it would allow you to build a battery bank bigger than Tim.

You make it sound like Tim is a pretty big fella. Do we have a new phrase now in the DIY Solar Forum lexicon?

“Bigger than Tim” -gigantuous

 

[timselectric]

You make it sound like Tim is a pretty big fella. Do we have a new phrase now in the DIY Solar Forum lexicon?

“Bigger than Tim” -gigantuous

No lol

 

[Kornbread]

Threw this together quick while I sit in another pointless meeting, might be helpful.
View attachment 192171

IIRC, 18650 has the 304Eve @$109 and that's preorder but when I try to add more than 9 cells to the Ezeal cart, it reverts back to 1. Does that indicate Ezeal only has 9 304Eve cells?

Just seen that Ezeal has bulk pricing. Has anyone given that a try?

 

[42OhmsPA]

IIRC, 18650 has the 304Eve @$109 and that's preorder but when I try to add more than 9 cells to the Ezeal cart, it reverts back to 1. Does that indicate Ezeal only has 9 304Eve cells?

Just seen that Ezeal has bulk pricing. Has anyone given that a try?

There was an additional discount on the 304s from 1865 when I added them to my cart.
I was able to add 16 of the 304 from Ezeal to my cart earlier.

I haven't looked into bulk pricing.

 

[Shinzul]

Is it possible to build a DIY battery bank which can communicate with another battery bank in parallel?

For example, I have 1200ah of EG4 lifepower batteries connected to a EG4 communication hub - I'm thinking of DIYing my own second battery bank. By my calculations, for another ~1200ah of batteries to add, I would save $6,000 (about 36%) after all costs are factored in if I DIY'd the second battery bank.

I'm trying to decide if it's worth my time to figure it all out.

 

[houseofancients]

Is it possible to build a DIY battery bank which can communicate with another battery bank in parallel

Yes, but you need the same BMS

For example, I have 1200ah of EG4 lifepower batteries connected to a EG4 communication hub - I'm thinking of DIYing my own second battery bank.

Not sure if the comms hub supports bms'es other than eg4

By my calculations, for another ~1200ah of batteries to add, I would save $6,000 (about 36%) after all costs are factored in if I DIY'd the second battery bank.

At those numbers, your charge and discharge rates will be extremely low, and comms maybe not be needed so bad.

I'm trying to decide if it's worth my time to figure it all out.

Probably not, alternative option would be replacing the EG4 BMS in the eg4's by a different one, then also using that BMS for your diy builds

 

[Dave911]

Threw this together quick while I sit in another pointless meeting, might be helpful.
View attachment 192171

I think those cells are still too expensive. I've been testing a number of 12 volt, 100ah batteries and I am pulling close to 105 ah out of each one. Most of them I bought for $167 each. And that was buying them one to three at a time and that includes shipping, but not tax. That includes a BMS and case and assembly. It seems like these cells should be more like $100 /kwhr or less. I thought I read that they were dipping below $100 in bulk. What do they cost if bought directly from China ??

 

[Dave911]

Who could lift it?

Once again, not enough tools.... you need an engine hoist or hydraulic lift platform.
Every house should have at least one of each.

Tool Junkie...

 

[42OhmsPA]

I think those cells are still too expensive. I've been testing a number of 12 volt, 100ah batteries and I am pulling close to 105 ah out of each one. Most of them I bought for $167 each. And that was buying them one to three at a time and that includes shipping, but not tax. That includes a BMS and case and assembly. It seems like these cells should be more like $100 /kwhr or less. I thought I read that they were dipping below $100 in bulk. What do they cost if bought directly from China ??

They are likely reject 105ah cells in the pre-made, hopefully not pouch cells. They aren't user serviceable and I wouldn't run them in series for 48V.

Here's a quote I had a couple days ago for 280Ah new old stock cells from China, they apparently sold out so I didn't do the math.

 

[JJJJ]

Once again, not enough tools.... you need an engine hoist or hydraulic lift platform.
Every house should have at least one of each.

A spare, just in case the neighbor borrows one LOL

 

[JJJJ]

Currently have CATL 8s packs, two on Overkill BMS and one on JK Active. Surprisingly they run fairly close together through the Victron Distributor. Still hoping to upgrade to all JK Active in the future.

 

[740GLE]

Who could lift it?

Tims electric doesn’t need to lift it, he pushes the earth down.

 

[Brucey]

They are likely reject 105ah cells in the pre-made, hopefully not pouch cells. They aren't user serviceable and I wouldn't run them in series for 48V.

Here's a quote I had a couple days ago for 280Ah new old stock cells from China, they apparently sold out so I didn't do the math.
View attachment 192305

So $55 per cell and then $14 for shipping. $69 is a huge savings over say rept from sunfunkits.

 

[740GLE]

So $55 per cell and then $14 for shipping. $69 is a huge savings over say rept from sunfunkits.

Are they the same quality as SFK?

Or are we just chasing the cheapest cells to compare to the cheapest assembled off the Amazon?

 

[captalfonzo]

they were
Envisions grade a are now , as they are cheaper, perform the same or better , i can get them locally ( 30 minute drive) , and are the exact same dimentions , so they fit the seplos mason boxes i use exclusively

Just got 2 apexium boxes. 18650 hade 280 ah for $99. they should be in this week. So guess we'll see how this solar journey go's

 

[42OhmsPA]

So $55 per cell and then $14 for shipping. $69 is a huge savings over say rept from sunfunkits.

Yes but SFK claims to be grade A with test reports, however I would not buy from them based on past shenanigans seen here and removed from youtube.
If it weren't for the 2 month+ estimated wait and way things are in the world I would have ordered them. They also have USA stock for $88 / cell with free shipping.
(gobel power) for anyone interested.

Are they the same quality as SFK?

Probably not, we may never know.

Or are we just chasing the cheapest cells to compare to the cheapest assembled off the Amazon?

I was mainly after best value and seeing what prices from China are doing to hopefully predict where stateside is headed.
I'm not interested in pre-made on amazon until they hit $75 for a 12V 100Ah, then I might consider ripping them apart for the cells.

 

[Kornbread]

Yes but SFK claims to be grade A with test reports, however I would not buy from them based on past shenanigans seen here and removed from youtube.

Yep, if more people knew what they threatened to do to Ray Builds Cool Stuff, bet a lot of people would shop elsewhere.

 

[Danke]

Yep, if more people knew what they threatened to do to Ray Builds Cool Stuff, bet a lot of people would shop elsewhere.

Unless I missed it in his videos, Ray doesn’t do the full discharge rate test. Just capacity tests.

 

[Dave911]

They are likely reject 105ah cells in the pre-made, hopefully not pouch cells. They aren't user serviceable and I wouldn't run them in series for 48V.

I have tested a number of them so far for capacity (11 so far). So far they are all within 2% of each other. They are testing at 102-103 ah. The variability might be due to the tester. This is more consistent that I expected.
These must have decent quality cells to be so consistent. They are supposed to be prismatic. They are going into two banks of 48 volts. They come with a 5 year warranty.
If I have balance issues, I'll figure it out.

I don't understand what you were quoted. $55 per cell? That figures out to 34 cells? That seems really cheap, but they are unavailable. So that doesn't work. Do those have any type of warranty? Or is it a crap shoot?