Which colour wire

billyboya

Esteemed Pedelecer
Aug 10, 2016
1,137
90
73
uk
Can someone here tell me on a 48v battery charger with 2 wires brown and blue which colour go to positive is it brown or blue
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Brown.
 

Plas man

Pedelecer
May 12, 2022
100
41
of topic but when wire a new 3 pin plug , use the first two letters ,

brown - BR bottom right (the fused one)

blue - BL bottom ieft

green/yellow - top single (Earth wire)
 

StuartsProjects

Esteemed Pedelecer
May 9, 2021
1,798
1,014
Can someone here tell me on a 48v battery charger with 2 wires brown and blue which colour go to positive is it brown or blue
Checking the polarity of the charger output with a multimeter would be a good idea.

One might assume the charger puts +Ve on the brown, but then we dont know which charger you have or where it came from.
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
78
Checking the polarity of the charger output with a multimeter would be a good idea.

One might assume the charger puts +Ve on the brown, but then we dont know which charger you have or where it came from.
Very well put.
And many here have experinced that Chinese companies do not always follow conventional colour coing either! A multimeter is as you mentioned, the only safe way to check 100%.
I myself was completely unclear (implying not clear enough for a fully SAFE answer!), as to whether he was talking about the AC mains input, or the DC output, his query was so badly phrased in my view.
And it appears that I was not alone looking at other posts here......
He is of course a danger to himself and anything electrical that he touches!
Sad but true to say!!
I am sure, if he took the wrong advice (several possibilities here that are meant for different situations), and either blew himself, and/or his e-bike up, he would then come back and complain!!!
regards
Andy
 

billyboya

Esteemed Pedelecer
Aug 10, 2016
1,137
90
73
uk
Very well put.
And many here have experinced that Chinese companies do not always follow conventional colour coing either! A multimeter is as you mentioned, the only safe way to check 100%.
I myself was completely unclear (implying not clear enough for a fully SAFE answer!), as to whether he was talking about the AC mains input, or the DC output, his query was so badly phrased in my view.
And it appears that I was not alone looking at other posts here......
He is of course a danger to himself and anything electrical that he touches!
Sad but true to say!!
I am sure, if he took the wrong advice (several possibilities here that are meant for different situations), and either blew himself, and/or his e-bike up, he would then come back and complain!!!
regards
Andy
Why would i come back to complain. Nealh said Brown, as I believe he has seen charger before. Im sure he wont have said brown if he didnt know. I have now also placed meter on 200V DC placed red probe on blue wire - and black probe on + and it said --- 49.5 v which indicates to me brown is + and blue is --- which I've just found out on YouTube.

this is the charger which yes is Chinese. But green light stays on all the time, so it must be faulty as battery should charge up to 54v unless its the battery like Nealh seems to think



IMG_2342.JPG
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Your battery may have a low cell group and be out of balance, if any one cell group is fully charged then the bms stops the current flowing for charging so automatically the charger light will turn Green. The charger is adumb charger is simply lets the current flow if it is told to do so by the bms.

With China wiring it isn't a given that wire colours are 100% correct but generally we can asusme which is more then often correct, Brown & Red are used for v+ but also we have seen with multi wires used blue is used for lcds. But when only two colours are used we can be pretty certain of the Btown and Red. Like wise for Gnd often it is Black but in the absence of Black, Yellow will be used.
 

billyboya

Esteemed Pedelecer
Aug 10, 2016
1,137
90
73
uk
Your battery may have a low cell group and be out of balance, if any one cell group is fully charged then the bms stops the current flowing for charging so automatically the charger light will turn Green. The charger is adumb charger is simply lets the current flow if it is told to do so by the bms.

With China wiring it isn't a given that wire colours are 100% correct but generally we can asusme which is more then often correct, Brown & Red are used for v+ but also we have seen with multi wires used blue is used for lcds. But when only two colours are used we can be pretty certain of the Btown and Red. Like wise for Gnd often it is Black but in the absence of Black, Yellow will be used.

I have to be 100% Nealh its the battery, as I will contact the seller in china, doubt he will do anything, but will see. as something isn't right agree, and i would have thought 49.5V would be enough charge to turn over motor
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Does the charger show 54.6v on the output lead ?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
The battery reading 49.5v means nothing without knowing the 13 cell group voltages, to do that the shrinkwrap will have to be cut to access the bms to take those group readings.
 
Last edited:

billyboya

Esteemed Pedelecer
Aug 10, 2016
1,137
90
73
uk
Does the charger show 54.6v on the output lead ?

on the discharge lead its same 49.5V

same on the charging lead too when green light is on I measured on those 2 screws on jack plug + and - same 49.5v
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Test the charger on it own without it being connected to the battery, If the charger doesn't show 54.6v on the charge connector then it is duff.
 

billyboya

Esteemed Pedelecer
Aug 10, 2016
1,137
90
73
uk
Test the charger on it own without it being connected to the battery, If the charger doesn't show 54.6v on the charge connector then it is duff.
you mean plug it into mains but not into battery, as just tested it, and nothing at all put meter on 200V DC
so maybe this is my problem the charger and not battery. although why did battery go down at 49.5v after being fully charged.

can you recommend then nealh a good 48v charger with a jack plug on charging end. I don't like the idea of those 2 screws as feel the wires can come loose which they did other day and it sparked so prob messed up charger. I don't need to know what V are going into batt from charger as green light should say when its full

IMG_2332.JPG
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
It is highly important to know the charger is outputting the correct voltageto prebent ove rcharge and fires occurring, although I have set ans adjusted mine I always check them periodically.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH
Check your chargers fuse/s it will have one in the 13a plug and maybe one inside the charger, it's not improable one or the othe rhas blown if you get no V reading.
 

billyboya

Esteemed Pedelecer
Aug 10, 2016
1,137
90
73
uk
Check your chargers fuse/s it will have one in the 13a plug and maybe one inside the charger, it's not improable one or the othe rhas blown if you get no V reading.
there is no fuse inside charger. But would green light come on if it’s the fuse in the plug as I’m sure you won’t get any light on charger

I forgot to mention but don’t think this will have a fuse as it’s a adapter what those 2 pins plug into so it does seem it’s the charger gone

6D078D13-1CC9-496C-BB9F-993525A8D3E7.jpeg
 
Last edited:

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,981
8,565
61
West Sx RH

billyboya

Esteemed Pedelecer
Aug 10, 2016
1,137
90
73
uk

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
78
Why would i come back to complain. Nealh said Brown, as I believe he has seen charger before. Im sure he wont have said brown if he didnt know. I have now also placed meter on 200V DC placed red probe on blue wire - and black probe on + and it said --- 49.5 v which indicates to me brown is + and blue is --- which I've just found out on YouTube.

this is the charger which yes is Chinese. But green light stays on all the time, so it must be faulty as battery should charge up to 54v unless its the battery like Nealh seems to think



View attachment 47210
Green LED staying on all the time, is ALSO an indicator that the battery is not charging, as it has "slipped" below the voltage level (for any one of many reasons) at which the charger is allowed to charge!
The reason I commented as I did previously, was because your original question did not indicate whether you were asking about the mains input AC side or the output DC side....At least one other was also mislead by your question.....So I was not alone in that, and I treat safety with a huge respect! Many don't!!