NewStats: 3,263,812 , 8,181,481 topics. Date: Sunday, 08 June 2025 at 03:33 AM 681m51

BigDickProblems:


Yes it’s true, I know that as well. The statement does not oppose Li-ion, but do you see Li-ion in that high capacity range (20Ah, 23Ah, 50Ah etc) like LifePo4? I guess the answer is no. It’s not common to see them, not like they don’t exist.

This is also obvious in this thread, because a lot builders here uses 3.2Ah or a little above capacity. If there were 20Ah Li-ion cells around, nobody will have that luxury of time to weld 644 cells when you can easily do so with just 8cells. Haba. This is why I said that LifePo4 contains high capacity in small body.

That's fine, I wanted to be sure the latter part above was the argument you were making 👍🏾

AndroBlaze:


That's fine, I wanted to be sure the latter part above was the argument you were making 👍🏾

I can’t argue with you sef, cos you’ve been here long b4 I even developed interest in Solar.

I'm more of the typical theory guy, who was the best in physics back then in Sec School.

BigDickProblems:


I can’t argue with you sef, cos you’ve been here long b4 I even developed interest in Solar.

I'm more of the typical theory guy, who was the best in physics back then in Sec School.

lol, you can argue with anyone ooo...everyone should be here to learn and the knowledge is vast and does not stay static, so anyone could be wrong at anytime.

Good morning everyone and a happy month to ya'll, it seems the mods no longer need my presence here as I always get banned for posting stuff here.

Intellab:
I had some challenges with my previous 18650 battery setup. I used 644 cells configured as 92P7S, but it couldn't power my 1HP Sumo pump effectively.

So, I upgraded to 314Ah LiFePO4 batteries — 8 pieces in total, giving me around 8kWh of usable energy. I built the pack using a JK Bluetooth BMS with a 1A active balancer, 4*250w solar s, felicity MPPT.
Batteries and the BMS were sourced from Valto.

I also switched to a 0.5HP Sumo pump, and now I have 24-hour power supply. The Sumo, washing machine and a lot runs smoothly — everything is up and running without issues 24/7.

If a 12v could power 0.5hp, then this should.

BigDickProblems:


I can’t argue with you sef, cos you’ve been here long b4 I even developed interest in Solar.

I'm more of the typical theory guy, who was the best in physics back then in Sec School.

It is just that you do sound too practical compared to us with physical experience. Different cells, different chemistry, different applications.

And don't see fire when you make comments. Have you experienced this before? NO!!! You only got the info from the usual YOUTUBE.

At times you make it look that each time one uses lithium ion, next expectation is fire. This is the mindset I desire you remove from your thoughts.

There are several dangers in cars, home, work place etc..

1. Ceiling fan can drop
2. Car accident
3. 220v socket just beside your beside
4. Powebanks are lithium ion based and ppu go about with them.
5. Sitting above car tanks with petrol
6. Gas cylinders in homes
7. Overhead water tanks
8. Phone in your pocket with lithium ion cell
9. Pop can crash
10. Generators with petrol placed in the house/verandah
11. The list plenty bro....

dollarnaira:


It is just that you do sound too practical compared to us with physical experience. Different cells, different chemistry, different applications.

And don't see fire when you make comments. Have you experienced this before? NO!!! You only got the info from the usual YOUTUBE.

At times you make it look that each time one uses lithium ion, next expectation is fire. This is the mindset I desire you remove from your thoughts.

There are several dangers in cars, home, work place etc..

1. Ceiling fan can drop
2. Car accident
3. 220v socket just beside your beside
4. Powebanks are lithium ion based and ppu go about with them.
5. Sitting above car tanks with petrol
6. Gas cylinders in homes
7. Overhead water tanks
8. Phone in your pocket with lithium ion cell
9. Pop can crash
10. Generators with petrol placed in the house/verandah
11. The list plenty bro....

Lols. This is true my Boss. You are a professional and that is why you have eliminated such fear. Unlike Beginner like me, the fear is always their 😂

BigDickProblems:


Sorry, I forgot to leave a reply.

You have to connect each of them in 8 Series to get 25.6V
Because 8 × 3.2V = 25.6V

that series means constant Ampere but increase in voltage. So if you add up all the voltage of the 8 cells in series, it will give you 25.6V.
Total capacity (let’s assume each cell is 20Ah):
25.6V 20Ah
=512Wh

Since each cells (I.e one cell) are all connected in 8 series, you can call it 8S1P or 1p8S. This means you’ll need an 8S (eight series) BMS.

Just understand that BMS helps manage your connection on each series. So if you create a 10series connection, you’ll need a 10s BMS.

This is a diagram below

Good explanation,but I couldn't locate d 1p in d diagram.
What if d 8 cell is to be arranged to get 12.8v?

billyG:

Good explanation,but I couldn't locate d 1p in d diagram.
What if d 8 cell is to be arranged to get 12.8v?

So from all my explanations, you can’t still figure this out? Lols, Abeg o 😂
I’m still a young man.

BigDickProblems:


So from all my explanations, you can’t still figure this out? Lols, Abeg o 😂
I’m still a young man.

I hope it is not too much for you...point in your drawing where d parallel connection is.

billyG:

I hope it is not too much for you...point in your drawing where d parallel connection is.

Each of the cells are 1p. You Series 8 of them, it becomes 1P8S or 8S1P.

Intellab:
I had some challenges with my previous 18650 battery setup. I used 644 cells configured as 92P7S, but it couldn't power my 1HP Sumo pump effectively.

So, I upgraded to 314Ah LiFePO4 batteries — 8 pieces in total, giving me around 8kWh of usable energy. I built the pack using a JK Bluetooth BMS with a 1A active balancer, 4*250w solar s, felicity MPPT.
Batteries and the BMS were sourced from Valto.

I also switched to a 0.5HP Sumo pump, and now I have 24-hour power supply. The Sumo, washing machine and a lot runs smoothly — everything is up and running without issues 24/7.

Probably you did something wrong or the cells where already losing there capacity, 644 cells that huge bro, maybe you used soldering iron to degrade their capacity while assembling it.

iraybuju:


Probably you did something wrong or the cells where already losing there capacity, 644 cells that huge bro, maybe you used soldering iron to degrade their capacity while assembling it.

If the cells are not laptop extracted, I see no reason why it should work at a huge 7s. It goes beyond how he soldered. He could even spot weld but used a poor of fake strip.

I have 288 cells at 3s all soldered for a reason but powered 0.5h sumo without blinking.

WHERE IS TETRALOGY?

dollarnaira:


If the cells are not laptop extracted, I see no reason why it should work at a huge 7s. It goes beyond how he soldered. He could even spot weld but used a poor of fake strip.

I have 288 cells at 3s all soldered for a reason but powered 0.5h sumo without blinking.

Yes we can’t overrule that fact, poor soldering or welding can lead to multiple open/disconnected ings that’s possible what happened

i need this spot welder

iraybuju:


Probably you did something wrong or the cells where already losing there capacity, 644 cells that huge bro, maybe you used soldering iron to degrade their capacity while assembling it.

No. I spot weld.

dollarnaira:
If a 12v could power 0.5hp, then this should

Actually, I was trying to power a 1HP Astra Sumo pump using an 18650 battery pack.
After that, I built an 8kW LiFePO4 system and installed a 0.5HP Sumo pump instead.
The reason for the downgrade was that the LiFePO4 setup couldn’t handle the surge required to start the 1HP pump. So, I had to switch to the 0.5HP unit.

Intellab:


Actually, I was trying to power a 1HP Astra Sumo pump using an 18650 battery pack.
After that, I built an 8kW LiFePO4 system and installed a 0.5HP Sumo pump instead.
The reason for the downgrade was that the LiFePO4 setup couldn’t handle the surge required to start the 1HP pump. So, I had to switch to the 0.5HP unit.

8kwh is huge oo.
Inverter size, cable size, terminals firmness. I really wish you could go back to check the above? My 2nd bank of just 1.5kwh was still able to run the 0.5h with 3kwh Satchet inverter.

Intellab:

No. I spot weld.

What of nickel strip size?
Inverter size and brand?
Cable size?

Intellab:


Actually, I was trying to power a 1HP Astra Sumo pump using an 18650 battery pack.
After that, I built an 8kW LiFePO4 system and installed a 0.5HP Sumo pump instead.
The reason for the downgrade was that the LiFePO4 setup couldn’t handle the surge required to start the 1HP pump. So, I had to switch to the 0.5HP unit.

What's the size of the bms used in the build as well as your inverter size and voltage. Please also provide the max amp draw of your pumps if possible.

Most lifepo4 cells can handle output of 1c even though we're advised to run continuously at 0.2 - 0.5c, so if your battery is a 300ah battery pack you can pull 300a without issues, your only limitation will be your BMS and cable size.

So do provide us the above let's critic ur build

saint2ace:


What's the size of the bms used in the build as well as your inverter size and voltage. Please also provide the max amp draw of your pumps if possible.

Most lifepo4 cells can handle output of 1c even though we're advised to run continuously at 0.2 - 0.5c, so if your battery is a 300ah battery pack you can pull 300a without issues, your only limitation will be your BMS and cable size.

So do provide us the above let's critic ur build

200a JK Bluetooth BMS with 1a active balancer from Valto. 3000w pure sine wave inverter.
I used 6mm cable. My battery is 314ah.

Dear Diy lifepo4 builders,

I intend going into this soon as resources to build Lithium-ion is very costly now, and majorly most parts I used in building are always ordered from China.

From my own perspective or view, it seems lifepo4 cells bloat like the regular powerbank cells, what are the majors in place to tackle this issue?

Intellab:

200a JK Bluetooth BMS with 1a active balancer from Valto. 3000w pure sine wave inverter.
I used 6mm cable. My battery is 314ah.

What the voltage of your system? 12v 24v or 48v cos 6mm cable is actually too small for a 12v or 24v, even a 48v system will struggle.

Also lok at your bms setting to ascertain the settings for your charge and discharge cos most BMS come presetvto just 40a.

Revert when u can.

officialfestus:
Dear Diy lifepo4 builders,

I intend going into this soon as resources to build Lithium-ion is very costly now, and majorly most parts I used in building are always ordered from China.

From my own perspective or view, it seems lifepo4 cells bloat like the regular powerbank cells, what are the majors in place to tackle this issue?

Most battery chemistries will bloat when over charged, same is attainable with our banks but if care is taken to charge it as it should, you won't have a problem with bloating.

Have you asked why the chargers made for lithium batteries generally are Constant Current and Constant Voltage systems? Once it gets to the desired voltage it stops, no need for absorption. However due to the fact that we still use inverters or chargers (due to cost or financial restraint) meant primarily for lead acid batteries, we tend to slightly overcharge our batteries which in turn results to bloating. If we however stay within the range then bloating would not be a problem, but very slight bloating is expected and totally natural.

BigDickProblems:


Each of the cells are 1p. You Series 8 of them, it becomes 1P8S or 8S1P.

Ok prof...u too much!

officialfestus:
Dear Diy lifepo4 builders,

I intend going into this soon as resources to build Lithium-ion is very costly now, and majorly most parts I used in building are always ordered from China.

From my own perspective or view, it seems lifepo4 cells bloat like the regular powerbank cells, what are the majors in place to tackle this issue?

From onset I like to source materials locally to build cells from cables to terminals. No vex, it was a major reason I weld cells using soldering iron. Nickel strip is difficult to source locally but lead, soldering iron is just along your street. To source BMS and active balancer.. .....hmmm

saint2ace:


Most battery chemistries will bloat when over charged, same is attainable with our banks but if care is taken to charge it as it should, you won't have a problem with bloating.

Have you asked why the chargers made for lithium batteries generally are Constant Current and Constant Voltage systems? Once it gets to the desired voltage it stops, no need for absorption. However due to the fact that we still use inverters or chargers (due to cost or financial restraint) meant primarily for lead acid batteries, we tend to slightly overcharge our batteries which in turn results to bloating. If we however stay within the range then bloating would not be a problem, but very slight bloating is expected and totally natural.

I thought that the function of the bms if we use chargers or inverters meant for lead acids batteries.

dollarnaira:


From onset I like to source materials locally to build cells from cables to terminals. No vex, it was a major reason I weld cells using soldering iron. Nickel strip is difficult to source locally but lead, soldering iron is just along your street. To source BMS and active balancer.. .....hmmm

soldering is a tedious task and often times very rough, unlike welding.

Eid Mubarak! Ya'll.

Is it feasible to use 550w s instead of 300w for a 24v system?