What kind of BMS can i use on a 52v 14s 8p battery?

G

GodsWarrior

10 mW
Joined
Jul 9, 2020
Messages
32
Ok so i built myself a 14s 8p (52v) battery fully charged is 58.8v...i got a 48v 14s BMS...that when i test the output on BMS reads 51.3 and when i test directly to battery ( bypassing BMS) it reads 58.8v. ?do i have a bad BMS or did i do something wrong? Is there a 48v 14s. And a 52v 14s bMS???? I woul appreciate your help...thanx guys.
 
I'd recommed going on this website Bestech Power.
http://www.bestechpower.com

My personal specific choice would be this model:
http://www.bestechpower.com/518v14spcmbmspcbforli-ionli-polymerbatterypack/PCM-D131.html

Matador
 
As long as its a 14s bms correct? Because some say 14s 48v and some say 14s 52v. Are they the same thing just different way if naming them???
 
14s is 52.2V. Check your wiring diagram, should be 15 connections to the cells including negative black wire
 
Ok so my wiring is ok 14 strings plus 1 negative... And the batteries are sanyo panasonic 3500mah cells they used to be 3 48v 10.5mah battery packs i dissasembled them and made a 52v 8p battery pack ,fully charged is 58.8v. The only thing im missing is BMS. I bought one that said 48v 14s BMS and through bms it reads 51.2v and if i bypass it directly to battery it reads 58.8v. . The wiring is ok i checked it,. So the only thing i can think of is bad BMS...does it matter when they call it 14s 48v or 14s 52v????
 
The reason i ask this question is because, some sellers say 48v 14s BMS and some say 52v 14s BMS ...arent they both the same thing?? Or ???
 
14s 52v
13s 48v
 
GodsWarrior said:
My question is this..when i buy a BMS, is there a difference between 14s 48v. And 14s 52v??
Click to expand...
If all concerned are using similar chemistries (nominal 3.6 - 3.7V per cell) then usually a pack called 52V will be 14S.

But I've seen 14S called "56V" I guess for marketing purposes.

With LFP 48Vnominal is 16S, since each cell is only 3.2V

With LI standard for 48Vnominal is 13S, which requires 52-54.6V for charging purposes.

That is actually a bit lower pack voltage than most other chemistries, 3.6Vpc works out to 46.8Vnominal but that is standard for COTS ebikes.

Hope that helps.
 
To actually answer the question

when selecting a BMS, besides the issues of quality, like accuracy, reliability, longevity, adjustability, communications capabilities

the # of cells (balance wires) in series (14S) is important, to match the pack layout

And the voltage of the setpoints matching what you want for your cell chemistry

LI different from LFP different from LTO.

Best IMO is to look at ones capable of handling all three, so you know you can **adjust** the setpoints for the care protocol **you** think is best for your use case.
 
Before you start asking questions answer all the questions we have thoughtfully asked for you so we could help you how many wires on your BMS 15 or 14 ? How many cells in series ? Let's get the basic answers in and then we can go forward.
If you want to be totally confused I can help on that
Oh I'm at the beach lots of sun I had to reread it when I go home I read it again but it sounds like you might have a channel shut off on your BMS. or not reading loose sense wire ?
.
 
I DID mention that i got a 14s 48v bms and the question( the title reads 14s 8p 52v battery) ...and what you said makes sense..but i already checked all the balancing wires and everything is ok...i belive i got a defective bms because the seller i got it from is all of sudden playing ignore the customer...but its ok,got another one on the way... Hope fully this one is 100% functional...
 
Bms could be perfectly fine...just turned off. Have you tried a quick charge? Test it it's off by putting an appropriate load across the output. If it's off that 51v will drop to nothing. (I'm assuming it doesn't have an on/off switch/wires). On it should show full voltage on output.
Since your using used cells, check that the cell group voltages aren't out of limits and bms is off as protection.
Number of wires can be a little ambiguous as some bms's have a built in negative and others have an external sense wire for negative. In that way 15wires 'could' be either a 14s or 15s bms.
 
GodsWarrior said:
All in all its a marketing term when they say 14s 48v. What it really is ...is a 52v 14s...
Click to expand...
No, it is the norm for makers of cheap-chinese gear to not have decent English language documentation

and for its sellers to have no clue about the technology they are selling.

IMO 99% would be more accurate and helpful if they had the ability to do so

just not how that market works.
 
I tried already adding a load to it and the 51v doesnt drop, it stays at 51v. And thats at the BMS output..also under load i turn on controller and powers on then imediatly turns off again...weird so im not an expert or nothing but i teouble shooted all my basics...wiring, parallel voltage, adding a load etc... Ima wait for my new BMS if that fails maybe i should concider another carrer...jejejeje
 
So two frozen channels not monitored ? Just use the pack without BMS for a couple miles and then check cell voltage. Or new BMS ? You have a C.A.
 
You must log in or register to reply here.

Similar threads

N
Can you just convert a 48v battery to a 52v battery by adding one more cell pack ?
Replies
13
Views
665
eMark
eMark
Doctorbass
UL2271 Battery Certification Confusion - Cell spacing & max battery Voltage
Replies
1
Views
318
DaLanMan
DaLanMan
B
Battery pack shuts off after a while
Replies
2
Views
312
bogddy
B
M
How Do I Know My Battery Is Balanced charged?
2
Replies
26
Views
1,676
eMark
eMark
C
What kind of safety measures do you take when building battery at home?
2 3
Replies
55
Views
2,510
Cyclomania
C
Back
Top