Yet another "Recommend Me" thread, first run at a 24v battery...

[Rednecktek]

OK, so there are SSSOOO many things I don't know about building batteries, or more specifically the BMS end of batteries. I've been looking around but I think either I'm after a unicorn or what I want doesn't exist anywhere. Due to the nature of my job, I have VERY limited time between when I get my vacation check and when I get back to work, so places like AliBaba aren't going to work due to the shipping delays. Same with batteries, but more on that later.

Here's my NEEDS:
24v 8s BMS (right?)
200a Discharge (my unit draws about 150 under max load)
Low Temp Charging Protection
Affordable as possible. There's a fine line between Does-The-Job reliable and Victron Flexing your wallet.
Somewhere I can actually get one shipped to me in the US without having to wait 6 months and/or massive shipping costs

What would be Nice but not NEEDED:
Communication with a Growatt AIO (specifically the 3kw/24v model)
Active cooling fan on the heat sink

What I DON'T need:
Bluetooth control
Internet access
Monthly performance reporting
Satellite TV
Dog Washing Service Mode, I don't even HAVE a dog!


My plan is to build this all into a cooler for insulation with whatever the best-bang-for-the-buck 200+AH cells are. I'm also planning a small side system for the heating pads that will be inside, but that's another system that will plug into the side powered off a 12v FLA, a 400w system, and a thermostat with 4 heating pads inside the box.

My goal is to replace the 6 FLA's at my camp (24v, 180Ah usable) with a single unit, but my biggest concerns are that 1: it's unattended for a year at a time sometimes, and 2: it's below freezing many weeks a year, which is often the same time I'm shoreside and get to go up there. Having said that, I'm hoping to do this on a bit of a budget as I'm confident that I will DESTROY this battery somehow, either through ignorance or environmental effects, so I don't want to be out a lot of money.

Next question, who is our Go-To supplier for good cells in the US nowadays? What should I know about the different cell types like EVE and LISHEN and SuchCom?

Links please! And yes, "Out-Of-Stock" doesn't count.

 

[Steve_S]

Yes, 24V = 8S LFP Configuration.
Point to note, Airfreight a BMS to US is CHEAP and fast - remember these things do not weigh much ad there are several suppliers in the US that have stock BUT you have to check first. Current Connected, Signature Solar and several more are worth looking at for BMS and bits.

Cells from vendors are also available in the states with stock but it is a premium due to the shipping, duties etc being all rolled into the final price tag. Ray from TX likes Jenny Wu but there are a couple of more, check Will's links which apparently he updated a few days ago. Note that smaller cells are selling less & less as everyone goes for the 280AH+bigger, this means that 100AH and such are moving less and there is a bit more of a glut now than before so better pricing is possible.

Communications with Growatt ? Sure some BMS' can do so but what do you expect to accomplish with that ?
There are BMS' out there which are compatible and some vary a bit as to what they can actually do.

 

[Rednecktek]

Yes, 24V = 8S LFP Configuration.
Point to note, Airfreight a BMS to US is CHEAP and fast - remember these things do not weigh much ad there are several suppliers in the US that have stock BUT you have to check first. Current Connected, Signature Solar and several more are worth looking at for BMS and bits.

It's a personal gink to pay more in shipping than the cost of the item. Call me weird. I'll happily take any links you have though.

Cells from vendors are also available in the states with stock but it is a premium due to the shipping, duties etc being all rolled into the final price tag. Ray from TX likes Jenny Wu but there are a couple of more, check Will's links which apparently he updated a few days ago. Note that smaller cells are selling less & less as everyone goes for the 280AH+bigger, this means that 100AH and such are moving less and there is a bit more of a glut now than before so better pricing is possible.

I was planning on using 200+Ah cells mostly due to physical space limitations. If money were no object and I could afford a body-size cooler to mount it in, I could easily go with 3x100ah cells and get a really big battery. I realize there's a price premium for anything, unfortunately I can save time OR save money, but I can't do both.

What I did find, and I hope the offer is still around in July (or something comparable) is a Set of 310Ah Cells for about $1000ea, so $2k for my pack and almost double the Ah of my FLA set. Now to find a 200a 24v BMS...

Communications with Growatt ? Sure some BMS' can do so but what do you expect to accomplish with that ?
There are BMS' out there which are compatible and some vary a bit as to what they can actually do.

That's why it's on the Nice-But-Not-Needed list. I figured if the Growatt could talk to it then I'd get better performance and hopefully avoid some of the issues others have had with low voltage trips and such. Eh.

 

[Steve_S]

Well think of it this way... If it is in US Stock, S&H+++ is all rolled into the Sale Price, it works out almost the same if you airfreight it and if there is a SALE on that often can cover that cost. I have done a LOT of it and it is how it ends up... I do not think there is much difference being that I'm in Canada & your in the States but our duties etc are not the same so you hafta ask what S&H Air would cost as opposed to sea ship & then compare to US Vendors with US Stock.

I'm now done with my buying and doing the full final build which is taking me a long time, because it even involves building (structure) modifications. IF I was building right now "today" I'd drive up the road about 800km and buy Canadian LFP Cells and related kit but that was not an option until recently.

https://www.currentconnected.com/ <--- this is HighTechLab's business site
https://shop.signaturesolar.us/ <--- Will loves these guys

My suppliers fall outside of your scope, so I cannot suggest US Stores/Vendors as such but HighTechLab is a really good lad who knows his stuff.

 

[chrisski]

I really don’t think what you are asking for is available. I’m mostly following to see what you find.

The only hope I see for this is batteries being available on the for sale section on this forum:

Batteries for Sale

Not using an old set of batteries? Sell them here!

diysolarforum.com

I’ve been watching Craigslist for Decent Solar Equipment, and rarely does something pop up Except for solar panels, which in my area there are deals to be had. I’ve seen one or two Growwatts listed in two years, and I think that was as part of a sale of a cabin.

Facebook Marketplace is something else I looked at a little and I can get to search within 500 miles of my area, but I have just found solar panels and in my case not worth driving For.

I tried getting 25 ah cell thinking they were a deal at first from a supplier like Battery+, but the price was still more than I had originally figured for shipping and taxes.

 

[Rednecktek]

So far the only thing I've ever found that seems to meet my needs is the Daly 24v 200a model. I'm a little nervous due to all the horror story threads about Daly BMS's though. It advertises that it meets my needs though, soooo... hmmm...

As a side note, my plan was to assemble the pack, throw it on my battery charger in AGM mode, let it sit, then throw it on my MPPT controller with programming for the LiFe settings to top it off. Any issue with that? I can't see buying a whole new special charger for a single battery pack.

 

[chrisski]

For my Aims Charger, I opted for Gel instead of Lithium or AGM due to the lower voltages:

I’ve ordered two cheaper DALY BMSs from EBay and had them in a couple of weeks. Both came from China. The seller does not sell the BMS you’re looking for, but here’s the link:

Waterproof BMS 8S 24V 20/30/40/50/60A LiFePO4 Battery Charger Proection Balanced | eBay

Find many great new & used options and get the best deals for Waterproof BMS 8S 24V 20/30/40/50/60A LiFePO4 Battery Charger Proection Balanced at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I’m sure ts drop shipped from China.

 

[Loadtoad]

Check out this shop, has excellent reviews from members here: https://www.docanpower.com/index.php?route=product/category&path=59_60_154

 

[Steve_S]

 

[Rednecktek]

Check out this shop, has excellent reviews from members here: https://www.docanpower.com/index.php?route=product/category&path=59_60_154

So I was looking at their JBD 7s-20s BMS and I'm a little confused as to what I'm seeing there. 1: Do I just connect up the terminals to the 8 cells I'm using and let the other 12 dangle free? Can I recycle this if I decide to make a 48v battery later? 2: What's the honkin huge round thing on the end?

So does the picture look like everything I'll need to build my 24v 280Ah battery? (Not including fuses and box and such of course.)

Side question, difference between CATL and EVE? I can get 8 CATL 302Ah for only about $90 more. Worth it? Yes/No?

 

[Rednecktek]

Anyone?

 

[B-ManFX4]

Anyone?

You can get the EVE 304AH cells for $158 each. I saw Will say he found the EVE cells to be of good quality. I just received mine from Jenny Wu. They are perfectly balanced and arrived in flawless condition. Great packaging for shipping. Of course these have the terminal post instead of the terminal stud you selected.

Yes - you wire the BMS to the cells and the unused leads have to be properly shorted together depending upon your configuration. Yes, you can add cells and use the additional wiring as needed. See attachments for more info.

The "honkin huge round thing on the end" is a heavy duty contactor. That BMS can activate the contactor and disconnect the battery from the load if wanted.

 

[Rednecktek]

Wow, that JBD looks like WAY more than I want to tackle for a first build. I think I might stick with the Daly for simplicity's sake. Remember, there's a good chance I'll somehow destroy this battery and I don't need any help from an overly complicated BMS.