Building a big 280AH 24V Battery - Whats the best supplier for cells right now?, also, sanity check for my numbers.

[mndare]

Got another 12 x 280 cells from Xuba last Friday. Short 10 bus bars but otherwise no issues. Put another 560 AH 12 volt pack together and did a capacity test. 98.9887% capacity using the 120 amp BMS with low Temp cutoff I have been discussing. BMS is spectacular. Bench top 15 amp load applied.

 

[ghostwriter66]

Got another 12 x 280 cells from Xuba last Friday. Short 10 bus bars but otherwise no issues. Put another 560 AH 12 volt pack together and did a capacity test. 98.9887% capacity using the 120 amp BMS with low Temp cutoff I have been discussing. BMS is spectacular. Bench top 15 amp load applied.

View attachment 8525

What was the BMS again -- sorry ??

 

[mrdavvv]

@ghostwriter66 Yes!, wich bms?

@Steve_S Got it, hopefully you get some time to upload results when posible, ill keep an eye on your thread for any updates. About the BMS, you are right... i checked your Chargery units and they seem very nice and complete, howemever at the moment im looking for something simple and stupid, so maybe not the best option for me.... i think i will open a new topic so maybe the forum can trow some advice for my specific situation.

@mndare Great!, looking nice!... i really want to get some of those cells, but im having trouble with amy since his logistics company cant send to mi ZIP code (Outside US), what a boomer, im looking at some options but its getting complicated...even my usual forwarder in Shenzen is avoiding shipping this kind of products They dont want to see anything related to batteries .

 

[mndare]

@ghostwriter66 Yes!, wich bms?

@Steve_S Got it, hopefully you get some time to upload results when posible, ill keep an eye on your thread for any updates. About the BMS, you are right... i checked your Chargery units and they seem very nice and complete, howemever at the moment im looking for something simple and stupid, so maybe not the best option for me.... i think i will open a new topic so maybe the forum can trow some advice for my specific situation.

@mndare Great!, looking nice!... i really want to get some of those cells, but im having trouble with amy since his logistics company cant send to mi ZIP code (Outside US), what a boomer, im looking at some options but its getting complicated...even my usual forwarder in Shenzen is avoiding shipping this kind of products They dont want to see anything related to batteries .

Im in Canada

 

[ghostwriter66]

Im in Canada

The BMS you're talking about when you say "using the 120 amp BMS with low Temp cutoff I have been discussing. BMS is spectacular."

Thx

 

[Carly]

The BMS you're talking about when you say "using the 120 amp BMS with low Temp cutoff I have been discussing. BMS is spectacular."

Thx

His post with link and photos to that BMS is here:

Just Place new Order on Alibaba- 280AH x 8 for 1260.00 USD Delivered, Grade A to Canada

The BMS's I have gotten are the following. https://www.aliexpress.com/item/4000425316662.html?spm=a2g0s.9042311.0.0.15004c4d8Vun6O. They are the same units as sold on Bigbattery.com that Will is raving about but better priced, 120 amp instead of 100 amp, in stock and directly from China. Have...

diysolarforum.com

 

[GMB]

My Xuba 280's are due to arrive on Wednesday. I still have to wait for the cell charger & 180W tester to arrive before I can do anything with them

I ordered 16 of these batteries as well and I am new to solar and especially to building any type of battery. I was under the assumption that I could bottom balance the batteries once they arrive and start using them right away to complete my solar system installation. Is there something else I should be doing with them before hooking them up to the Victron SCC?

 

[ghostwriter66]

I ordered 16 of these batteries as well and I am new to solar and especially to building any type of battery. I was under the assumption that I could bottom balance the batteries once they arrive and start using them right away to complete my solar system installation. Is there something else I should be doing with them before hooking them up to the Victron SCC?

There is NO need to bottom balance the battery unless you are using the batteries for Transportation or Emergency Equipment ... If you are using it for Solar Power Storage you want to TOP balance and there are numerous posts on how to do that effectively and efficiently ...

 

[GMB]

There is NO need to bottom balance the battery unless you are using the batteries for Transportation or Emergency Equipment ... If you are using it for Solar Power Storage you want to TOP balance and there are numerous posts on how to do that effectively and efficiently ...

I was getting my info from this video from Will's Youtube. After watching it several more times trying to grasp all of this, it sounds like I wouldn't need to top or bottom balance them since Amy sent a video of all the cells being tested before packaging for delivery. Just make sure I have my temp sensor hooked up and a low voltage and high voltage cut off in place and stay between 20%-80% SOC. Is that correct for these 280ah cells since they are brand new grade A cells?

Also, this is listed on Will's website regarding building your own LiFePO4 pack - "Bottom Balancing the Cells: This is REQUIRED when first building a LiFePO4 battery. "

This is all very confusing...

 

[lonnf]

Look at my thread, ordered 8 x 280 AH grade A cells today for 1280.00 USD delivered, much better price than your link

Szxuba Ev Lifepo4 Prismatic Cells 280ah Lifepo4 Rechargeable 3.2v 280ah Li-ion Lithium Battery For Solar System - Buy Lifepo4 Prismatic Cells 280ah li-ion Lithium Battery 3.2v 280ah Lifepo4 Battery Cell Product on Alibaba.com

Szxuba Ev Lifepo4 Prismatic Cells 280ah Lifepo4 Rechargeable 3.2v 280ah Li-ion Lithium Battery For Solar System - Buy Lifepo4 Prismatic Cells 280ah li-ion Lithium Battery 3.2v 280ah Lifepo4 Battery Cell Product on Alibaba.com

www.alibaba.com

These cells seem like a smoking deal...except the shipping seems so pricey! I'm thinking about ordering 8 x 280ah also. Did they have cheaper options for shipping to Canada? Also, did the price you got $1280 include taxes/brokerage (If you don't mind me asking...) I'm in Victoria, BC...where did you get yours shipped to? Thanks!

 

[ghostwriter66]

I was getting my info from this video from Will's Youtube. After watching it several more times trying to grasp all of this, it sounds like I wouldn't need to top or bottom balance them since Amy sent a video of all the cells being tested before packaging for delivery. Just make sure I have my temp sensor hooked up and a low voltage and high voltage cut off in place and stay between 20%-80% SOC. Is that correct for these 280ah cells since they are brand new grade A cells?

Also, this is listed on Will's website regarding building your own LiFePO4 pack - "Bottom Balancing the Cells: This is REQUIRED when first building a LiFePO4 battery. "

This is all very confusing...

Like all of us - you have to do your own research and try to determine why some ppl are saying this or that .... sometimes ppl bottom balance because the BMS that they are going to use that is going to measure the SOC requires them to have a full and then empty for it to set the gauge right -- but honestly -- most of the better newer ones don't require that ...

Again --most of the time Bottom Balancing is ONLY for Emergency Equipment and vehicular that you need to squeeze every drop of energy out of ..

Also not sure why you are setting the charge parameters between 20-80% .. that means that there is 40% of the battery that you are not using ... once again -- IF YOU can afford to leave 40% of your battery unused and still have enough power to get through the day/night then that fine -- but perhaps do 10-90% initially to see how you like it ... honestly -- if you are using your battery daily and not storing it full for periods of time then 10-100% is just as fine ... personally i am always more concerned about over discharging then over charging ...

BUT YES - one of the ways you can top balance is to hook up your BMS (as long as it has hopefully active balancing) -- and then charge the battery ... I typically TOP Balance by LFPs once and then never worry about them again -- once you do it right the first time then it takes allot to knock them out of whack ..... BUT with that said -- you need to make sure that ALL your cells after you connect them and charge them are the same voltage ... and then personally i would put a good load on them for a while -- let the battery sit -- and then measure each cell again -- to see if the voltage is still all equal ...

 

[GMB]

Like all of us - you have to do your own research and try to determine why some ppl are saying this or that ....

Thank you for taking the time to respond and I respect your opinion greatly and one of your posts is the reason I am jumping into making my own batteries instead of buying the Battleborns, thus saving me a ton of $$.

As far as doing my own research - that is what I did and led me to the video posted previously and the quote directly from Will's website. I'll post it again; Bottom Balancing the Cells: This is REQUIRED when first building a LiFePO4 battery. It is also repeated in the previously posted video. What is your comment about this statement? Is it false? Is it old and outdated information? Is it a difference of opinion? Do you have some other research I could read or look at that would contradict this? The fact that he capitalized the word "REQUIRED" leaps out to me as something I should be doing.

Again --most of the time Bottom Balancing is ONLY for Emergency Equipment and vehicular that you need to squeeze every drop of energy out of ..

I see no mention of emergency equipment or vehicular use "ONLY" in the video posted or the website link from above? Is this just common knowledge and Will is not clued in on the subject? Is he giving out old and outdated information?

Also not sure why you are setting the charge parameters between 20-80% ..

Because I have no idea what I am doing and it was written in giant white letters on the screen from the previously posted video and discussed at around 4:27. Screen shot below from said video (Did you watch this?). To be fair, he did say maybe he wrote 20%-90% on his website. I checked his website and found him saying 10%-90% to be on the safe side, so you are both in agreement there. I will be over panel'd and bought more than enough battery capacity for my needs (thanks to you saving me so much $ on building my own) so I would like to keep the batteries around as long as possible and that seems to me why he was recommending those settings.


Thank you again for all of your help, and I truly mean no disrespect with this post as I am just trying to hash this all out and understand why there is conflicting information. I have a first grader knowledge of solar and battery building and that is why I am spending 5+ hours a day on this forum reading everything and watching every video on the topic that I can.

 

[mndare]

These cells seem like a smoking deal...except the shipping seems so pricey! I'm thinking about ordering 8 x 280ah also. Did they have cheaper options for shipping to Canada? Also, did the price you got $1280 include taxes/brokerage (If you don't mind me asking...) I'm in Victoria, BC...where did you get yours shipped to? Thanks!

Price was full in and delivered to Squamish. I have since gotten 12 more cells and getting another 4 this week. They weigh a lot so shipping is what itr is. That is UPS air, I have not asked for a sea shipping price.

 

[mndare]

You always need to balance any cells when you first construct a pack, then the passive balancing from your BMS will keep them well balanced.

 

[tictag]

The biggest points to take away from Will's video are:

1. You DO NOT need to manually balance your cells if they are new
2. You DO NOT need to manually balance your cells if you have a BMS
3. You DO NOT need to manually balance your cells if you know that are well balanced
4. In other words, the ONLY times you need to balance your cells are if your application critically depends on eeking out every joule (which, frankly, are few and far between - bottom balance) or when you know they are knackered (top balance).

His video and recent comments all seem to be deeply concerned about balancing cells in a new battery ... buy a BMS! Balancing cells is what they are born to do.

Edit: Re-worded for clarity.

 

[mndare]

The biggest points to take away from Will's video are:

1. You DO NOT need to manually balance your cells if they are new
2. You DO NOT need to manually balance your cells if you have a BMS
3. You DO NOT need to manually balance your cells if you know that are well balanced
4. In other words, you ONLY need to balance your cells (bottom balance) if your application critically depends on eeking out every joule (which, frankly, are few and far between) or when you know they are knackered (top balance).

His video and recent comments all seem to be deeply concerned about balancing your battery ... buy a BMS! Balancing cells is what they are born to do.

Balancing is one thing, overcharging or overdischarging is another. The voltage drops so fast at the bottom knee of the discharge curve...many a battery pack have been destroyed when left to the human eye to keep watch on a gauge...just saying.

 

[tictag]

...and that's the other thing a BMS does.

 

[mndare]

Yes the overcharge damage or drain damage is prevented with a BMS

 

[GMB]

...and that's the other thing a BMS does.

Do you have any suggestions on what can be done until I have my BMS situation figured out - in regards to protecting the bank from over charge and over discharge? I was looking at the Victron Battery Protect, but with my inverter (Giandel 24v 3000w model) it doesn't appear feasible with my limited knowledge level. I read about the Sterling ProLatch-R and looked over the user manual, but the programming seems daunting, but does appear that it would work. I already have a low temp sensor that goes with the Victron SCC.

 

[lonnf]

Price was full in and delivered to Squamish. I have since gotten 12 more cells and getting another 4 this week. They weigh a lot so shipping is what itr is. That is UPS air, I have not asked for a sea shipping price.

Thanks! My son lives in Squamish! Great place!

 

[Sgt Raven]

Thank you for taking the time to respond and I respect your opinion greatly and one of your posts is the reason I am jumping into making my own batteries instead of buying the Battleborns, thus saving me a ton of $$.

As far as doing my own research - that is what I did and led me to the video posted previously and the quote directly from Will's website. I'll post it again; Bottom Balancing the Cells: This is REQUIRED when first building a LiFePO4 battery. It is also repeated in the previously posted video. What is your comment about this statement? Is it false? Is it old and outdated information? Is it a difference of opinion? Do you have some other research I could read or look at that would contradict this? The fact that he capitalized the word "REQUIRED" leaps out to me as something I should be doing.
View attachment 8585


I see no mention of emergency equipment or vehicular use "ONLY" in the video posted or the website link from above? Is this just common knowledge and Will is not clued in on the subject? Is he giving out old and outdated information?


Because I have no idea what I am doing and it was written in giant white letters on the screen from the previously posted video and discussed at around 4:27. Screen shot below from said video (Did you watch this?). To be fair, he did say maybe he wrote 20%-90% on his website. I checked his website and found him saying 10%-90% to be on the safe side, so you are both in agreement there. I will be over panel'd and bought more than enough battery capacity for my needs (thanks to you saving me so much $ on building my own) so I would like to keep the batteries around as long as possible and that seems to me why he was recommending those settings.
View attachment 8549

Thank you again for all of your help, and I truly mean no disrespect with this post as I am just trying to hash this all out and understand why there is conflicting information. I have a first grader knowledge of solar and battery building and that is why I am spending 5+ hours a day on this forum reading everything and watching every video on the topic that I can.

Will still has things and videos up, that may not be where lots of us are at today. Things in the LFP world have been changing pretty fast.
The BMS Will thought was the best for the money a couple of months ago, is not the ones he thinks is best today. He thought separate port BMSs were better than common port BMSs. he has changed his mind in the last few months.

Improvise, Adapt, and Overcome......

 

[tictag]

Do you have any suggestions on what can be done until I have my BMS situation figured out - in regards to protecting the bank from over charge and over discharge?

I would just either monitor the terminal voltage, don't let it go below 2.5V per cell or 20V for a 24V (nominal) battery* or you get one of those cheap battery alarms for an audible trigger, and make sure your SCC is configured not to charge above 3.65V per cell or 29.2V for a 24V (nominal) battery.
*Important note: A LFP battery has an almost entirely flat discharge curve, then at about 3.0V per cell, the voltage will tank very quickly (i.e. in minutes). Some people set their low voltage cut-off at 3.0V per cell (24V) for this reason.

I already have a low temp sensor that goes with the Victron SCC.

That sensor will be only be used to modulate the charging current if, for example, the battery temperature gets too hot. AFAIK, it won't prevent sub-zero charging. Could be wrong but I would certainly check before relying on it for this purpose.

 

[GMB]

I would just either monitor the terminal voltage, don't let it go below 2.5V per cell or 20V for a 24V (nominal) battery* or you get one of those cheap battery alarms for an audible trigger, and make sure your SCC is configured not to charge above 3.65V per cell or 29.2V for a 24V (nominal) battery.
*Important note: A LFP battery has an almost entirely flat discharge curve, then at about 3.0V per cell, the voltage will tank very quickly (i.e. in minutes). Some people set their low voltage cut-off at 3.0V per cell (24V) for this reason.

That sensor will be only be used to modulate the charging current if, for example, the battery temperature gets too hot. AFAIK, it won't prevent sub-zero charging. Could be wrong but I would certainly check before relying on it for this purpose.

Thank you tictag as always for taking the time.
It does say this in the Amazon description for the temp sensor. "For lithium batteries temperature data is used to disable charging when they are too cold: charging lithium batteries near or below freezing causes permanent damage to the cells."
But I will take a look at the actual manual on Victron's site to make 100% sure.

 

[tictag]

Ahhh, I'm thinking of something completely different. My Victron MultiPlus has a temp sensor that I had to fit to the battery - all it does is reduce the charge current if the battery gets to hot. Conflated these two different products. Sorry for the misunderstanding.

 

[Sgt Raven]

Thank you tictag as always for taking the time.
It does say this in the Amazon description for the temp sensor. "For lithium batteries temperature data is used to disable charging when they are too cold: charging lithium batteries near or below freezing causes permanent damage to the cells."
But I will take a look at the actual manual on Victron's site to make 100% sure.

I thought I read somewhere that some SCCs were adding a low temp cutoff to theirs. It shouldn't be too hard to add that feature to the firmware of a SCC that has a temp probe.