Build a Battery … Where to start?

[MattMan119]

When I started there was no real interest is building my own battery. Now, I have this real need to build a battery..

I have a question about sourcing cells, it would appear that you guys all keep up with the latest news and prices where is a good source and what kind of things should I know prior to ordering ?

what BMS do most of you use seems JK BMS but not really sure..

I have seen a lot of material here to help, but not know what is important is like going to google .. just too much data to know the good stuff..

Might build both a 24v for trailer and 48v for RV …

Thoughts?

 

[Drunkin Solar]

If you want the easy way of doing it I can recommend the Seplos Mason Kits. Everything needed to properly assemble your cells is included and are reasonably priced factory direct. Have built three of these in the last few months with great success. They offer the kits in both 24v and 48v.

Battery energy storage system | Seplos Technology

Wholesale battery energy storage system, 48v lifepo4 battery pack at Seplos Technology, a leading supplier certified by ISO, CE, TUV

www.seplos.com

 

[740GLE]

The Luyuan thread got me into looking at kits/cases.

Remember though they were primarily known for selling quality cells a good prices, then they started offering semi customizable cases.

Jot down what you want AH size AH count and BMS peak current and they can put together a quote, you pay then wait 2-3 months and lots of boxes arrive.

So far I haven’t heard Luyuan cell quality has dipped, but cells quality does seem to fluctuate.

 

[Brett V]

I've built several batteries.
Zero complaints with EVE cells sourced from Docan US stock.
https://www.docanpower.com/index.php?route=common/home
and Overkill BMS
https://overkillsolar.com/

 

[Kornbread]

You will probably get better pricing ordering from China stock, but better pricing costs in longer shipping time. Be cautious, it's easy to get sub-par cells even when not ordering from the Ali's.

Docan power both U.S. and China warehouses
Gobel China warehouses
Luyan China warehouses
18650 battery store ... US based, decent prices, poor communication
SunFunKits ... never ... just never.

Popular BMS's
jk bms ... noninverter is solid, 200amp w/2a active balancing <$100
jbd
overkill ... rebadge? Not that a rebadge is bad.

 

[MattMan119]

Wow that is a big difference in price.. US 82 vs China 62 same cells.. Wow .. Thats worth the wait..

So I ordered a few packs of connectors and leads and other things just to see if they really are the price listed, cause they are like marked up 1500% on amazon for some of this simple stuff..

Going to have to build one I think, this is very bad additiction .. but fun and rewarding. This is a much for DIY ..

 

[Kornbread]

Wow that is a big difference in price.. US 82 vs China 62 same cells.. Wow .. Thats worth the wait..

So I ordered a few packs of connectors and leads and other things just to see if they really are the price listed, cause they are like marked up 1500% on amazon for some of this simple stuff..

Going to have to build one I think, this is very bad additiction .. but fun and rewarding. This is a much for DIY ..

Whoa there ... don't forget to add in shipping and other fees to the cost of China sourced cells. It still comes out significantly less, but don't be surprised if those fees tack on +$500 to the raw cells. Forget about trying to ship a defective LiFePo4 cell back to the vendor as it will cost more than the cell is worth.

So far, I've had good luck purchasing flexible bus bars, foam, separator sheets, silicone covers for copper lugs, jk bms (only from Hanzkor), stuff like that from Aliexpress. Much cheaper than Amazon or eBay.

Temco hycraulic crimpers.

Temco copper welding wire. Currently, copper is pretty $high$.

Good multimeter, preferably a clamp meter that reads both ac and dc amps.

Battery box or build you own.

Absolutely not necessary, but a battery capacity tester is nice.

They are some good deals out there to be had, right now cells are the cheapest I've ever seen, but it's also easy to get taken for a ride. Be vigilant.

K

Thread 'Hithium 314ah Review/Capacity Test 333ah'

Oct 1, 2024

Picked up a zketech ebc a40l to test these new Hithium 314ah cells. If they test good, I'll probably be ordering more of them. First impressions, these are the flattest cells I own. With the grade 'b' Eve 304ah cells, you can clearly see the jelly rolls. With the Eve304ah grade 'a' cells from 18650Battery store, you can clearly see and feel the jelly rolls. Not quite as pronounced as the grade 'b' cells, but clearly there. These new Hithium 314ah cells are ruler flat. You cannot see or feel the jelly roll. They stack against each other with no gap.


Eve grade...

• Kornbread
• Replies: 53
• Forum: DIY LiFePO4 Battery Banks

• 

 

[ohmboy]

I have a question about sourcing cells, it would appear that you guys all keep up with the latest news and prices where is a good source and what kind of things should I know prior to ordering ?

I went with https://batteryhookup.com/ they have local pickup available if you are in the area. I was scared of ordering from overseas, but I think it's ok.

what BMS ?

Overkill Solar.

 

[Rednecktek]

I'm a big fan of JBD for their simple reliability. Daly works OK in a pinch, and I'm that weirdo that hates JK with a passion.

My build tools include a cheap lug crimper that goes from 6awg to 2/0 which is all I really ever run into. 6, 8, and 10awg I just use my hand crimper.

I buy the 1/4" red heat shrink ring terminals by the bucket, some heavy duty Pittsburg crimpers and the triangle type strippers, and packing tape (the fiber stuff when I can find it) with some heat shrink or electrical tape in red & black.

My bigger battery builds include a welder.

 

[MattMan119]

Whoa there ... don't forget to add in shipping and other fees to the cost of China sourced cells. It still comes out significantly less, but don't be surprised if those fees tack on +$500 to the raw cells. Forget about trying to ship a defective LiFePo4 cell back to the vendor as it will cost more than the cell is worth.

So far, I've had good luck purchasing flexible bus bars, foam, separator sheets, silicone covers for copper lugs, jk bms (only from Hanzkor), stuff like that from Aliexpress. Much cheaper than Amazon or eBay.

Temco hycraulic crimpers.

Temco copper welding wire. Currently, copper is pretty $high$.

Good multimeter, preferably a clamp meter that reads both ac and dc amps.

Battery box or build you own.

Absolutely not necessary, but a battery capacity tester is nice.

They are some good deals out there to be had, right now cells are the cheapest I've ever seen, but it's also easy to get taken for a ride. Be vigilant.

K

Thread 'Hithium 314ah Review/Capacity Test 333ah'

Oct 1, 2024

Picked up a zketech ebc a40l to test these new Hithium 314ah cells. If they test good, I'll probably be ordering more of them. First impressions, these are the flattest cells I own. With the grade 'b' Eve 304ah cells, you can clearly see the jelly rolls. With the Eve304ah grade 'a' cells from 18650Battery store, you can clearly see and feel the jelly rolls. Not quite as pronounced as the grade 'b' cells, but clearly there. These new Hithium 314ah cells are ruler flat. You cannot see or feel the jelly roll. They stack against each other with no gap.


Eve grade...

• Kornbread
• Replies: 53
• Forum: DIY LiFePO4 Battery Banks

• 

Yeah, i have most of the tools I will need from building the solar system for the RV .. I just ahve to be careful and get the good cells, seems like there is more then enough people that have ordered from safe places, I will find a safe one we know has good cells.

I went with https://batteryhookup.com/ they have local pickup available if you are in the area. I was scared of ordering from overseas, but I think it's ok.


Overkill Solar.

Thanks for this, the price of China and I'm in no hurry so slow shipping not a problem. (I can't seem to figure out where they are for pickup?)

I'm a big fan of JBD for their simple reliability. Daly works OK in a pinch, and I'm that weirdo that hates JK with a passion.

My build tools include a cheap lug crimper that goes from 6awg to 2/0 which is all I really ever run into. 6, 8, and 10awg I just use my hand crimper.

I buy the 1/4" red heat shrink ring terminals by the bucket, some heavy duty Pittsburg crimpers and the triangle type strippers, and packing tape (the fiber stuff when I can find it) with some heat shrink or electrical tape in red & black.

My bigger battery builds include a welder.

I have two 12v for my 24v trailer setup that is JBD. They seem to work well. Seems to really be JBD or JK is what most end up with.


Thanks all for feedback, helping me fill in the gaps..

 

[TechMaster_Sree]

if you are building both 24 and 48V battery then use and external connector then latter we can use this to do balancing if needed . so that you can use single NEEY balancer for both packs since LFP packs will not need frequent balancing with Active balancer if they are properly matched. You can also use BMS with Smart active balancers at extra cost.
connector example

 

[curiouscarbon]

Overkill Solar.

for what it's worth, not sure if it has come to your attention.

overkill solar is not stocking JBD BMS any more

 

[Drunkin Solar]

for what it's worth, not sure if it has come to your attention.

overkill solar is not stocking JBD BMS any more

View attachment 254618

Batteryhookup stocks JBD bms's in both 24v and 48v

 

[Andron]

In my 24v solar system I have two homemade 186ah batteries. They consist of BMS - Seplos v2 250a and cells - 8 x SVOLT 186ah

 

[AntronX]

18650batterystore is in Georgia so you may get cheaper shipping vs others.

 

[OzSolar]

When I started there was no real interest is building my own battery. Now, I have this real need to build a battery..

I've made several batteries plus bought several complete batteries from Battery Hookup. It's a fascinating website to watch just see what sorts of weird things they get in there.

Genuine Lithium Batteries for DIY Projects

Battery Hookup

batteryhookup.com

 

[Drunkin Solar]

I've made several batteries plus bought several complete batteries from Battery Hookup. It's a fascinating website to watch just see what sorts of weird things they get in there.

Genuine Lithium Batteries for DIY Projects

Battery Hookup

batteryhookup.com

Batteryhookup is a great place

They are honest priced really well, shipping is top notch, have been to their place in Pennsy and they have things you may not see anywhere else.
A fantastic operation that they run. All of the cells I've purchased have come from their shop for four different builds. All the the cells were grade A and have performed as such. Would like to see more love on this forum for these guys.

 

[Zwy]

Go with the Luyuan box and cells. I've been running a Luyuan box in the house, the cells hold balance very well. Easy to assemble.

 

[MattMan119]

Just crazy … I so want to do this just for fun.. but not today I guess .

 

[MattMan119]

Ok well I did it now..

Got me 16 304ah EV Cells on the way and
150a JBD BMS .. Should be a fun project ..

 

[Kornbread]

Ok well I did it now..

Got me 16 304ah EV Cells on the way and
150a JBD BMS .. Should be a fun project ..

Why 150amp?

 

[Tulex]

My recommendations are:

Read the crap out of this forum/watch some of Will's videos. So much great advice from some experienced people.
There is no one way to build a battery, but there are some basic does and don'ts.
Don't skimp on any item. The small difference in price for quality items is worth the safety it brings.
Know what you want to end up with. That dictates how much is DIY and how much is kit. Some people are OK with raw cells on a shelf, some like a manufactured look.
Know how many you really want to end up with and just do it. I built mine in 3 separate builds, and while I ended up saving money because prices came down, I still wish I had just built all 6 at one time.

Purchased cells 3 different times.
First was 32 cells a year and a half ago, with DIYPOW from overseas. Had issues, would not recommend them.
Second was 16 cells with EZeal a year ago from USA. Great experience.
Last was 48 cells from Gobel earlier this year from overseas. Another great experience.

I really like Seplos BMS, but some say they are expensive/hard to understand. They work well together and I've had excellent support from Seplos and on here.

 

[MattMan119]

Why 150amp?

No real reason other than I plan to put a 100A fuse on it anyhow, so I moved one size larger to give comfort that I am not skirting the limit.

With my 6000xp there is no real reason to go any bigger. I have 3 100A batteries already, this will be the 4th battery, so even at max 6000Xp pull we are looking at ~110-120amp, they can safely share that load ... at 30a (.3c and .1c respectively - if they share it evenly)

Reading the max 6000xp load, might even fuse it at 150a knowing it can run the entire thing. (But that said, I never or hardly ever for more then 20sec pull anything close to max. I have had 1 3000w L1 line warning from the day I installed the system, and I figured out that it was an very rare case of coffee brewing, espresso machine and heat pump all kicked in at the same time....

 

[MattMan119]

My recommendations are:

Read the crap out of this forum/watch some of Will's videos. So much great advice from some experienced people.
There is no one way to build a battery, but there are some basic does and don'ts.
Don't skimp on any item. The small difference in price for quality items is worth the safety it brings.
Know what you want to end up with. That dictates how much is DIY and how much is kit. Some people are OK with raw cells on a shelf, some like a manufactured look.
Know how many you really want to end up with and just do it. I built mine in 3 separate builds, and while I ended up saving money because prices came down, I still wish I had just built all 6 at one time.

Yeah, I'm sure there is a big build for a house in the future.

Purchased cells 3 different times.
First was 32 cells a year and a half ago, with DIYPOW from overseas. Had issues, would not recommend them.
Second was 16 cells with EZeal a year ago from USA. Great experience.
Last was 48 cells from Gobel earlier this year from overseas. Another great experience.

That part really had me worried, there are so many good and bad companies. But, at some point you got to just go with it and hope for the best.

I really like Seplos BMS, but some say they are expensive/hard to understand. They work well together and I've had excellent support from Seplos and on here.

I selected the bms based on getting Home Assistant connect to all the batteries in the trailer build, I know how they work and don't need start over getting them all connected to everything, I can just add another battery to the yaml and I am done.

Although I just got in a few extra toys for ESP32/8266 devices that include the CAM, modbus and a few others. Who knows what that will bring, maybe a MBMS (Master BMS) that connects to all the BMS's -and- shunt to give some details to the inverters and/or chargers.. IDK, depends, my career in computers started with communication of devices and connecting them, the tools are a lot cooler today, but the method are unchanged. Days of modems and RS232 have been replaced with Wifi/RS485/CAM/Bluetooth and TCP/IP .. But that is the fun part, some of the old and some of the new.

 

[Tulex]

Yeah, I'm sure there is a big build for a house in the future.

That part really had me worried, there are so many good and bad companies. But, at some point you got to just go with it and hope for the best.

I selected the bms based on getting Home Assistant connect to all the batteries in the trailer build, I know how they work and don't need start over getting them all connected to everything, I can just add another battery to the yaml and I am done.

Although I just got in a few extra toys for ESP32/8266 devices that include the CAM, modbus and a few others. Who knows what that will bring, maybe a MBMS (Master BMS) that connects to all the BMS's -and- shunt to give some details to the inverters and/or chargers.. IDK, depends, my career in computers started with communication of devices and connecting them, the tools are a lot cooler today, but the method are unchanged. Days of modems and RS232 have been replaced with Wifi/RS485/CAM/Bluetooth and TCP/IP .. But that is the fun part, some of the old and some of the new.

Buying the cells was the worst part for me. It's the biggest part of the investment with the most uncertainties.
The hard part for me was that some of the most recommended venders also had complaints from other people. I tried to find the balance of price and reputation. Gobel was my best experience, especially with it being form China. The communication was great. They provided all the requested documentation (tracking and cell spreadsheets), and the cells were the most balanced of the 3 companies I bought from. At the time, prices were great too.