New beginning

[Frogslayer]

48V Simple LiFePo4 Lithium BMS | Electric Car Parts Co

www.electriccarpartscompany.com

 

[Street Ryderz]

How low is to low though?

Mine was factory set to shut off at 41v I lowered that to 30. I thought that was ok though?
I had spoke and asked the seller about this and he told me don't go under 16v, but i have no clue why that seemed pretty low to me so i went with
30v control box cut off.

So far when i ride the 17 mile round trip journey, i've only lost 4.7v from 58v

I'm not sure if that is good or bad, all new to me

On a 48 v system 41v for the cut off is normal and right at the edge of being to low,this is based on lead acid batteries and 10.25 v each at the cut off which isn't really the best for them as 11v each would ensure a longer life span but they want you to get the longest run time possible being so limited. With lithium cells and the cells being arranged in poles it's a bit different each pole has the voltage of one cell and if the cells are rated say from 3.7 to 4.2 v then pulling them down below 3.7v will kill them off quickly so if you have 14 poles at 4.2v fully charged which is 58.8v then fully discharged is 3.7 x 14 =51.8 and much higher than the 41v cut off and really not good for the life of those cells. This higher cutoff voltage will yeild alot more cycles from the battery pack and reduce the chance of a bad cell effecting the packs performance.

 

[HumanPerson]

Ok, i i'll get a few cells and a new BMS....that is alot cheaper than getting another battery for now.

This is going to be a learning experience if i get it all right.

Wish me Luck!!

HP

 

[HumanPerson]

Ok, opened the battery and tested the cells....upon closer examination i seen a split in the side of one...yet it still held a charge.

I'm thinking this is the culprit as everything else checks out as far as voltage as well...but seen no splits on any of the other pouch cells.

I cannot find a Pylontech, LiFePO4 Pylontech Pouch Rechargeable Battery 3.2v R1M 020M111CENBG1120103A11265
The dimensions are: 3/8" thick 3 1/2" wide and 9 1/4" tall.

Can somone link me to any place that sells these please.

I've looked under a few different ways, all i find are the cylinder batteries.

What am i doin wrong?

 

[HumanPerson]

Ok here is a pic of what I see on the battery cell pouch

 

[HumanPerson]

battery pouch cell?

 

[HumanPerson]

Here are the 2 splits in the battery cell pouch
Cell pouch dimensions are:

H= 234.95mm (Height)

W=88.9mm (Width)

T=9.25 (Thickness)

 

[Frogslayer]

That's what makes the 18650 packs so nice Is how easy replacements are found.

 

[HumanPerson]

I think i found somethuing similar on alibaba lol


Just the dimensions are not quite right...why are these pouch cell batteries hard to find then?

LiPolymer LiFePO4...am getting cornfused!

 

[HumanPerson]

a bit of holiday music

https://files.catbox.moe/nh5dyh.mp4