Who is still building DIY batteries

[Dave911]

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

I'm looking for best value. The cheap batteries I have bought off Amazon and Ebay come with a 5 year warranty and I have found people who have used the warranty to success. But from what I have tested, they seem to be of fairly high quality from a consistency standpoint.

On the other side of the coin is buying them direct from China, assembled, or as cells and hoping for the best. I don't think anyone has any illusions about using a warranty on those cells after a month or so, if that.

In between are the US distributors selling loose cells for DIY. But they seem expensive to me.

These guys says cells can be had for less than $100/kwhr. I would sure like to know the source!

LFP cell average falls below US$100/kWh as battery pack prices drop to record low in 2023

After the trend of falling prices temporarily reversed last year, 14% year-on-year drop in Li-ion battery pack cost recorded by BloombergNEF.

www.energy-storage.news

 

[42OhmsPA]

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.

What C rates are you using to test?

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.

Good luck.

I don't understand what you were quoted. $55 per cell? That figures out to 34 cells?

Yes, plus freight. Came out to roughly $70 / cell all in.

That seems really cheap, but they are unavailable. So that doesn't work.

Nope but they will be again.
The 305 Ah AESC Envisions from 18650 seemed really cheap too, working great.

Do those have any type of warranty? Or is it a crap shoot?

Isn't most of it?
I'm not to worried about a warranty.
I'm more concerned with reliability and serviceability.

 

[ScrotpusGobbleBottom]

My battery pack is 128 LFP 280AH 48 volt system. It is self-balancing and keeps the cells within 10mv. I have 2 Overkill BMS 's and also two 5 amp balance boards. I balance just the top end of the Cells. The balance boards turn on at 54.2 volts to keep the Cells all good. Everything on the System is totally automatic and I do not have to babysit it. The System runs the entire house including a hot tub and 3 refrigerators a pool pump and 4 freezers. It runs the house for 3 days without solar. No electric bill.

That is a wonderful picture.

 

[G00SE]

Who could lift it?

Tim

 

[Kornbread]

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

Yeah, it's been a while since watching any of his battery videos. Is he posting again since the fiasco?
IIRC, this is the video SFK did not like and their reputed response in the second video.

x

x

 

[green mountain boys]

I'm looking for best value. The cheap batteries I have bought off Amazon and Ebay come with a 5 year warranty and I have found people who have used the warranty to success. But from what I have tested, they seem to be of fairly high quality from a consistency standpoint.

On the other side of the coin is buying them direct from China, assembled, or as cells and hoping for the best. I don't think anyone has any illusions about using a warranty on those cells after a month or so, if that.

In between are the US distributors selling loose cells for DIY. But they seem expensive to me.

These guys says cells can be had for less than $100/kwhr. I would sure like to know the source!

LFP cell average falls below US$100/kWh as battery pack prices drop to record low in 2023

After the trend of falling prices temporarily reversed last year, 14% year-on-year drop in Li-ion battery pack cost recorded by BloombergNEF.

www.energy-storage.news

Here is some pricing information and sources. If you find anything that needs correcting let me know and I will update.

DIY 48 Volt Battery
Supplier	Cell Type	Amp hours	Cost per cell	Shipping	# of cells	Cost of cells	Kilo watt hours	Busbars	Cost per kw/hr
Battery Hookup	EVE V3	280	$112.50	$150.00	16	$1,800.00	14.34	included	$136.02
18650 Battery Store	EVE V3	280	$102.50	$207.43	16	$1,640.00	14.34	included*	$128.87	*comes with fexible busbars
18650 Battery Store	EVE V3	280	$99.00	$572.55	48	$4,752.00	43.01	included*	$123.80	*comes with flexible busbars
18650 Battery Store	EVE V3	280	$95.00	$1,426.49	100	$9,500.00	89.60	included*	$121.95	*comes with flexible busbars
18650 Battery Store	EVE	304	$105.00	$207.43	16	$1,680.00	15.56	included*	$121.26	*comes with flexible busbars
18650 Battery Store	EVE	304	$102.50	$572.55	48	$4,920.00	46.69	included*	$117.63	*comes with flexible busbars
18650 Battery Store	EVE	304	$99.00	$1,184.04	100	$9,900.00	97.28	included*	$113.94	*comes with flexible busbars
Sun Fun Kits	EVE V3	280	$98.96	free*	48	$4,750.00	43.01	$48.00	$111.56	*shipping over 1 month **flexible busbars cost extra
Sun Fun Kits	EVE V3	280	$98.96	out of stock	48	$4,750.00	43.01			*"competitive freight rates from the Baton Rouge warehouse."
Sun Fun Kits	EVE	304	$106.25	free*	48	$5,100.00	46.69	$48.00	$110.25	*free shipping from China **Flexibile busbars cost extra
Sun Fun Kits	REPT	280	$93.75	free*	48	$4,500.00	43.01	$48.00	$105.75	* shipping over 1 month **flexible busbars cost extra
Sriko ***	Lichen	272	$95.00	$246.16	16	$1,766.16	13.93	No	$144.50	***grade B seller
Ezeal	EVE V?	280	$105.31	$239.84	16	$1,684.96	14.34	included*	$134.26	*busbars included but no description

 

[Dave911]

Here is some pricing information and sources. If you find anything that needs correcting let me know and I will update.

DIY 48 Volt Battery
Supplier	Cell Type	Amp hours	Cost per cell	Shipping	# of cells	Cost of cells	Kilo watt hours	Busbars	Cost per kw/hr
Battery Hookup	EVE V3	280	$112.50	$150.00	16	$1,800.00	14.34	included	$136.02
18650 Battery Store	EVE V3	280	$102.50	$207.43	16	$1,640.00	14.34	included*	$128.87	*comes with fexible busbars
18650 Battery Store	EVE V3	280	$99.00	$572.55	48	$4,752.00	43.01	included*	$123.80	*comes with flexible busbars
18650 Battery Store	EVE V3	280	$95.00	$1,426.49	100	$9,500.00	89.60	included*	$121.95	*comes with flexible busbars
18650 Battery Store	EVE	304	$105.00	$207.43	16	$1,680.00	15.56	included*	$121.26	*comes with flexible busbars
18650 Battery Store	EVE	304	$102.50	$572.55	48	$4,920.00	46.69	included*	$117.63	*comes with flexible busbars
18650 Battery Store	EVE	304	$99.00	$1,184.04	100	$9,900.00	97.28	included*	$113.94	*comes with flexible busbars
Sun Fun Kits	EVE V3	280	$98.96	free*	48	$4,750.00	43.01	$48.00	$111.56	*shipping over 1 month **flexible busbars cost extra
Sun Fun Kits	EVE V3	280	$98.96	out of stock	48	$4,750.00	43.01			*"competitive freight rates from the Baton Rouge warehouse."
Sun Fun Kits	EVE	304	$106.25	free*	48	$5,100.00	46.69	$48.00	$110.25	*free shipping from China **Flexibile busbars cost extra
Sun Fun Kits	REPT	280	$93.75	free*	48	$4,500.00	43.01	$48.00	$105.75	* shipping over 1 month **flexible busbars cost extra
Sriko ***	Lichen	272	$95.00	$246.16	16	$1,766.16	13.93	No	$144.50	***grade B seller
Ezeal	EVE V?	280	$105.31	$239.84	16	$1,684.96	14.34	included*	$134.26	*busbars included but no description

Thanks for putting this together!
Is the consensus that Sun Fun Kits must be avoided? Are there other good sellers in the US besides 18650?

 

[green mountain boys]

Thanks for putting this together!
Is the consensus that Sun Fun Kits must be avoided? Are there other good sellers in the US besides 18650?

I just put this together because I was having trouble trying to keep all the numbers straight in my head. It is much easier to compare options from a spreadsheet. I am not qualified to answer who is a good supplier and who is not. This list is not made to promote anyone just to compare current options. I am happy to make any corrections if you see an error or add more if you know of any.

 

[captalfonzo]

Thanks for putting this together!
Is the consensus that Sun Fun Kits must be avoided? Are there other good sellers in the US besides 18650?

This is a copy paste from Jenny Wu Docan Tech. EVE LF280K: 104USD per piece, when 32 pcs, 103USD per piece, shipping included to door. I also bought 2 Apexium boxes from her. They where at the door in 3 days. Great coms with her. Easy to purchase. Jenny@docanpower.com

 

[42OhmsPA]

This is a copy paste from Jenny Wu Docan Tech. EVE LF280K: 104USD per piece, when 32 pcs, 103USD per piece, shipping included to door. I also bought 2 Apexium boxes from her. They where at the door in 3 days. Great coms with her. Easy to purchase.

Did you purchase cells from 18650 as well?
Would you share some side by side photos of the Docan and 18650 cells?

Welcome to the forum.

 

[captalfonzo]

Did you purchase cells from 18650 as well?
Would you share some side by side photos of the Docan and 18650 cells?

Welcome to the forum.

yes i did buy from 18650. They where a pre buy. They where suppose to be in last week. I called them, they said they might be in this week. So i don't have them in hand. The boxes i ordered from Jenny had in 3days or so it was quick. If i had to do it all over again I would have ordered the cells from Jenny. Live and learn. She is fair. I'm in no hurry. I'm a newbie. I didn't plan on doing this for a few more years. San tan was closing their warehouse in GA and couldn't pass up the price. So went on SS and they had a deal going on so.... Now I'm the owner of 13K of solar and 13.5 of inverters. 30 K of batteries. Got the posts put in for the array. weather and work schedule is getting in the way. when it gets done ? I'm not getting my panties in a wade over it. All my friends keep asking. They are using me as a guinea pig. So if I'm successful they will jump on the wagon

 

[740GLE]

How much did they get you for the battery boxes?

 

[captalfonzo]

How much did they get you for the battery boxes?

With the extra wiring just under 700

 

[Johneb]

With the extra wiring just under 700

Apiece?

 

[captalfonzo]

Apiece?

yes

 

[OffGridInTheCity]

When I converted a 7 x 14 cargo trailer -> camper, I went with DIY 18650 14s88p (48v @ 260ah) battery. I placed it above the cabinets.....


They power a MPP Solar 3048LV (48v @ 3000w) inverter and after 3 years, ~8,000miles, and maybe 50 nights camping - it's worked very well!

However, it's only ~13kwh, we like winter camping, and we prefer the on-board 9,000BTU mini-split heat to heat-buddy. Last week I installed an additional 14s87p (48v @ 260ah) for a total of ~23kwh. This is enough to be 100% electric (mini-split, hot water, cooking, TV, Starlink) for 24hrs in pretty cold temps - e.g. 35F low. We do a 6 x 6 tailgate 'bedroom' which takes extra heat since it's just 18mil tarp.



Here's some pics of the 2nd battery install (green one)...





Just got back from our 1st trip with new battery and it looks like a winner. The space behind the lounge chairs was perfect for it. Balanced up nicely with the original 14s. I leave it <3.90v/pack for storage in-between trips.


3-4 years ago, I worried a bit about 18650 DIY in a trailer, but it's turned out to be a rock solid choice. And of course, 18650 is higher density power - e.g. takes less space for same kwh as LifePo4.

Not pushing - just showing that 18650 DIY can work A-OK in a trailer

 

[OffGridForGood]

Yup!
DIY Battery Building is Alive and Well

 

[Zwy]

Yup!
DIY Battery Building is Alive and Well

I ordered another 96 280Ah cells, cost was around $8800 shipped. JK BMS's were 6 with 4.3" displays for $877. I bought a used Hoffman cabinet for $250 and a pair of Amy's boxes for $650 shipped. $10,577, we can round it up to $11,000 with other misc items.

That is 86 Kwh. Prebuilt like EG4 Power Pro comes to $24,674 of which $1880 is tax because they don't know Iowa is tax free on solar systems. Alibaba had me fill out the form, tax free.

Can I build a battery bank for the $13,674 being compensated for my time? Well, it isn't quite that much (if this was for my house) because that $13,674 would give a tax credit of $4102 but in my case this is a business expense. That really is a moot point as any expense not incurred is profit in my pocket.

But SS does have free shipping right now.

 

[OffGridForGood]

I am excited to get my next set of 16 cells, will bring my ESS just shy of 100kWh...trying to catch up to @timselectric , but it seems like a lost cause

 

[Zwy]

I am excited to get my next set of 16 cells, will bring my ESS just shy of 100kWh...trying to catch up to @timselectric , but it seems like a lost cause

I'll be at 144Kwh between the house and shop. With the pair of boxes, I can shift about 28Kwh to one or the other. I just might have both in the house as I don't need to replace the Trojans in the golf cart yet. Shop uses on average 38Kwh/day this time of year but that load is mainly during the day. I really won't need much battery at night but will on cloudy days.

It will be interesting to see how this turns out.

 

[OffGridForGood]

NICE!
With the price of cells continuing to fall, it is tempting...maybe just one more pack...

 

[B-Mod]

I am glad to be just about done building batteries, or so I say right now, lol. I am at just over 230kwh, probably add about 30 to 40 kwh more. Building batteries is just not fun to me. Ground mounts, panels, pulling wire, hanging inverters is more my style of fun.

 

[Zwy]

NICE!
With the price of cells continuing to fall, it is tempting...maybe just one more pack...

At $78/cell, I wonder if it will get much cheaper. Biggest concern now is shipping costs could increase overnight and if cells get low enough in price, you might see those garbage cells we saw during covid come back as factories lower production and clear out the warehouses.

I would not wait for basement prices, one could get some cells that are junk.

 

[timselectric]

Fun, is doing laundry on the 4th day of rain.

And not caring.

 

[Zwy]

I am glad to be just about done building batteries, or so I say right now, lol. I am at just over 230kwh, probably add about 30 to 40 kwh more. Building batteries is just not fun to me. Ground mounts, panels, pulling wire, hanging inverters is more my style of fun.

What part of WI are you in? I could always stop by sometime in my travels.