is this cheap bms can do the work

[gamer]

in my country i have only this bms is it good or i need to look for samthing alse
i want to build 2X100 ah 4S 16.8V lithium battery

BMS 4S 100A Balancer 18650 Lithium Battery Protection Board Charging With Balance 14.8V

Module de charge de batterie 18650 100% neuf et de haute qualitéPOUR Panneau de protection Lithium POLYMERE (3.7V)Tension de protection contre la surcharge de la batterie à cellule unique : 4,21-4,29 VLa surcharge de la batterie à cellule unique protège la tension de récupération : 4,14-4,24...

www.jumia.ma

 

[MisterSandals]

i want to build 2X100 ah 4S 16.8V lithium battery

Is there a reason you are using 18650 cells to make 2 big batteries?
Why 16.8V? Is there a particular use for that voltage?

Sorry, i do not know about that BMS as there does not appear to be a brand or model or maker listed.

 

[gamer]

Is there a reason you are using 18650 cells to make 2 big batteries?
Why 16.8V? Is there a particular use for that voltage?

Sorry, i do not know about that BMS as there does not appear to be a brand or model or maker listed.

no no reason i was told its better 3S for 18650 cells. can you give me cheap bms because the daly ones are expensive for me right now

 

[MisterSandals]

3S for 18650 cells

18650 is 3.6V nominal
3.6V x 3 (3S) = 10.8V

want to build 2X100 ah 4S 16.8V

16.8V / 4S = 4.2V

What voltage are you trying to make?

 

[gamer]

18650 is 3.6V nominal
3.6V x 3 (3S) = 10.8V

16.8V / 4S = 4.2V

What voltage are you trying to make?

3S 4.2V = 12.6

 

[MisterSandals]

3S 4.2V = 12.6

You have 4.2V 18650's? My google-fu only shows 3.6V nominal.

Happen to have a link to the 18650's you have?

 

[meetyg]

3S 4.2V = 12.6

4.2v is the fully charged voltage.
You should plan according to the nominal voltage which is usually 3.6v for 18650 Lithium ion.

 

[gamer]

You have 4.2V 18650's? My google-fu only shows 3.6V nominal.

Happen to have a link to the 18650's you have?

i took them from used laptop i calculated when its fully charged

 

[MisterSandals]

i took them from used laptop i calculated when its fully charged

Ok, 3.6V nominal.
What voltage battery are you trying to make?
3S = 10.8V
4S = 14.4V

So you would need a 3S or 4S BMS.
What are looking to power with your battery?

 

[gamer]

Ok, 3.6V nominal.
What voltage battery are you trying to make?
3S = 10.8V
4S = 14.4V

So you would need a 3S or 4S BMS.
What are looking to power with your battery?

i have victron inverter 12V 2000watt 9v to 17v I WANT TO MAKE 2x150ah i dont know if i should make 4S or 3S i. use max 240 WATT PER HOUR IN THE NIGHT ALSO I DONT KNOW THE TICKNESS OF THE NICKEL I CHOULD USE ALL MY CELLS ARE 2a

 

[curiouscarbon]

dear @gamer, you mentioned nickel (strips) thickness.
have you found spot welder? kind regards

 

[gamer]

dear @gamer, you mentioned nickel (strips) thickness.
have you found spot welder? kind regards

yes i have

 

[MisterSandals]

i have victron inverter 12V 2000watt 9v to 17v

I would do 4S (14.4V nominal, 16.8V max) since that falls nicely in your inverter range.
To make 150Ah from 2Ah cells

150/4 = 37.x cells in parallel. You are more ambitious than me!

150Ah x 14.4V = 2160Wh

2160Wh / 240W = 9h runtime

Does the 240 W include the inverter loss (~15%)?

 

[gamer]

I would do 4S (14.4V nominal, 16.8V max) since that falls nicely in your inverter range.
To make 150Ah from 2Ah cells

150/4 = 37.x cells in parallel. You are more ambitious than me!

150Ah x 14.4V = 2160Wh

2160Wh / 240W = 9h runtime

Does the 240 W include the inverter loss (~15%)?

i didnt understand the last part i have another hybrid inverter working right now but its 48V it shows me the consumption thats where i get the 240 WATT

 

[MisterSandals]

the consumption thats where i get the 240 WATT

Is that showing battery consumption or appliance consumption?
If appliance consumes at 240W rate, battery is likely being drained at (240W / .85) = 282W

2160Wh battery / 282W = 7.6h runtime

 

[gamer]

Is that showing battery consumption or appliance consumption?
If appliance consumes at 240W rate, battery is likely being drained at (240W / .85) = 282W

2160Wh battery / 282W = 7.6h runtime

i will build just one right now this bms are expensive but it hase balancer in it i also have to ship them from aliexpress

 

[gamer]

I would do 4S (14.4V nominal, 16.8V max) since that falls nicely in your inverter range.
To make 150Ah from 2Ah cells

150/4 = 37.x cells in parallel. You are more ambitious than me!

150Ah x 14.4V = 2160Wh

2160Wh / 240W = 9h runtime

Does the 240 W include the inverter loss (~15%

i think 3S is better for me so the inverter can cut off at 3v per cell

 

[MisterSandals]

i looked on amazon and AliExpress for 18650 4S BMSs and do not recognize any so cannot really recommend one.

What you will need is one that handles your max battery amp draw. The 2000W inverter could draw quite a bit (2000W / .85 / 14.4v = 163A).
But if you only need to handle ~300W
300W / 14.4V = about 20A BMS (minimum)

The BMS in your first post looks sufficient for 4S up to 100A

 

[gamer]

i looked on amazon and AliExpress for 18650 4S BMSs and do not recognize any so cannot really recommend one.

What you will need is one that handles your max battery amp draw. The 2000W inverter could draw quite a bit (2000W / .85 / 14.4v = 163A).
But if you only need to handle ~300W
300W / 14.4V = about 20A BMS (minimum)

The BMS in your first post looks sufficient for 4S up to 100A

what wait is it if you have 150AH battery you need 150ah bms? im confused

 

[curiouscarbon]

what wait is it if you have 150AH battery you need 150ah bms? im confused

sorry if this is annoying. battery energy capacity usually Ah (amps x hours) and bms current capacity usually measured in A (amps)

150Ah battery not necessarily need 150A BMS. why? some battery can't do same number of amps as their amp hour number rating (2Ah cell compared to 2 Amps). some 2Ah cells can only do 1Amp if that makes sense.

"low power cell" like 2Ah can only do maybe 1Amp continuously until empty

"high power cell" like 2Ah can do maybe 4Amp continuously until empty

hope this helps, sorry if annoying to focus on that.