sorry just saw this message
Help to fault find on a Carrera Battery
- Thread starter Baz the balloon man
- Start date
Is that the charge socket?
If it is the charge socket, check again where the charge wires are fixed at the other end. That will eliminate any problem with the socket, fuse or wiring.
Ok the voltage across the charge port connected to the bike or of the bike is 0.
should I connect the terminal on PCB to the charger and test voltage across charge port again to see if it fused as the voltage will go back to it ?
should I connect the terminal on PCB to the charger and test voltage across charge port again to see if it fused as the voltage will go back to it ?
The wires out of charge socket to PCB terminals look great and they are very secure no movement I think it’s new never used.
You test with a meter to see if they're OK, not go by looks. When the meter says not OK, you look to find the cause.
ok there is 0 voltage at the charge input socket and 0 Voltage across the the PCB terminal s.
There is voltage across the Five Cell clusters ie 10 small colour wires at the side of the inner battery body but still have to get my head around this as to Neaths post
Do you know of any battery building books I could download load so I can understand the building of battery’s from sticking the individual cells together?
I watched a few U tube videos but I think a download PDF would be better.
I just tested a will not charge battery of a Bird Bike across the charging port and this is reading 11.7V and it’s a Two pin charger
There is voltage across the Five Cell clusters ie 10 small colour wires at the side of the inner battery body but still have to get my head around this as to Neaths post
Do you know of any battery building books I could download load so I can understand the building of battery’s from sticking the individual cells together?
I watched a few U tube videos but I think a download PDF would be better.
I just tested a will not charge battery of a Bird Bike across the charging port and this is reading 11.7V and it’s a Two pin charger
Both charge port and discharge port go via the BMS. They are not directly connected to the cells. The BMS needs to be able to turn off charging when full, and to turn off supply to motor when empty.
Your issue is probably not with the cells, although there is one thing to check there. It is more likely with the BMS or possibly that you do not have the matching charger.
If the charge port has more than two wires i.e. it has comms between charger and battery, then a dumb 2 wire charger will not work.
The thing worth checking and writing down is the voltage of each cell group. It is a 36V battery, so there are 10 cell groups. All those little wires both sides connect to the terminal plates that link one cell group to the next. They are the sensing and balancing wires to the BMS.
Each cell group has an end each side of the battery. You need to work out the order of those little wires, which is quite easy.
Make a list of all those wires - colour, which side of the battery - and then do the following.
1. Switch your multimeter to a DC voltage scale. The lowest range that is more than 42V, on cheap meters this is probably 0-200V.
2. Hold the black meter probe on any of the small wires, and keep it there. Don't move this one, it is a fixed reference for the measurements you are about to take.
3. Touch the red meter probe to each of the other small wires in turn. Write down against each wire the voltage shown on the meter. This may be positive, or negative. Make sure you record that as well as the numerical value.
4. When you have got them all, identify the largest negative reading. Now move the black meter probe to that wire, and do it all again. This should give you a positive reading at all of the other small wires, because the black probe is now on the negative end of the cell stack. Record all those numbers, and put them in order of size.
5. The voltage of each of your 10 cell groups is the difference between adjacent values. Either calculate them all, or measure them directly by moving both meter probes to adjacent wires, now you know their order.
You should now have 10 individual cell group voltages, and a total battery voltage. When you have those, post them and further advice may follow.
Your issue is probably not with the cells, although there is one thing to check there. It is more likely with the BMS or possibly that you do not have the matching charger.
If the charge port has more than two wires i.e. it has comms between charger and battery, then a dumb 2 wire charger will not work.
The thing worth checking and writing down is the voltage of each cell group. It is a 36V battery, so there are 10 cell groups. All those little wires both sides connect to the terminal plates that link one cell group to the next. They are the sensing and balancing wires to the BMS.
Each cell group has an end each side of the battery. You need to work out the order of those little wires, which is quite easy.
Make a list of all those wires - colour, which side of the battery - and then do the following.
1. Switch your multimeter to a DC voltage scale. The lowest range that is more than 42V, on cheap meters this is probably 0-200V.
2. Hold the black meter probe on any of the small wires, and keep it there. Don't move this one, it is a fixed reference for the measurements you are about to take.
3. Touch the red meter probe to each of the other small wires in turn. Write down against each wire the voltage shown on the meter. This may be positive, or negative. Make sure you record that as well as the numerical value.
4. When you have got them all, identify the largest negative reading. Now move the black meter probe to that wire, and do it all again. This should give you a positive reading at all of the other small wires, because the black probe is now on the negative end of the cell stack. Record all those numbers, and put them in order of size.
5. The voltage of each of your 10 cell groups is the difference between adjacent values. Either calculate them all, or measure them directly by moving both meter probes to adjacent wires, now you know their order.
You should now have 10 individual cell group voltages, and a total battery voltage. When you have those, post them and further advice may follow.
Hi Mathew.
The charger port only has Two wires red and black .
the discharge port has red and black the small wires connected to the PCB / BMS..
they do not go to the charging port .
The rest of your post I will get on this and work my way through it and let you know how I get on .
Cheers thanks for your help much appreciated.
The charger port only has Two wires red and black .
the discharge port has red and black the small wires connected to the PCB / BMS..
they do not go to the charging port .
The rest of your post I will get on this and work my way through it and let you know how I get on .
Cheers thanks for your help much appreciated.
Morning Mathew.
please see attached photos.
I am calling the charger port end the front of the battery .
looking on from this end so left side which had the red wire connected too.
from back to front
we have a black terminal with two wires red. And a sealed black wire next to it.
1. white
2. Blue
3.green
4.red
5.yellow
Right side back to front.
ignoring sealed black 2 wires going in
1.Green
2. yellow
3.grey
4.white
5. Orange
Setting 200V DC Black probe on 2 black wires left side of battery.
I assume this is a positive terminal ?
Black to Green. 4.68
Black to Yellow. 7.86
Black to Grey 1.58
Black to white. 11.81
Black to Orange 15.79
Black Probe to left side white wire. Red probe to right side
white to Green. - 1.57
White to yellow. 1.61
White to Grey. -4.66
White to White 5.54
White to Orange. 9.53
Black probe to Grey terminal left side of the battery.
Grey to White. 4.6
Grey to Blue. 1.5
Grey to Green. 8.1
Grey to Red. 16.1
Grey to Yellow. 12.1
Grey to the terminal that has the Two black wires. -1.5
Right hand side of the Battery.
Grey to Green. 3.0
Grey to Yellow. 6.2
Grey to White. 10.1
Grey to Orange 14.1
So Grey is the negative terminal on the right hand side of the battery ?
Not sure what you mean point 5 of your post ?
Cheers
Baz
Attachments
There is only one negative terminal, and one positive terminal for the whole cell pack, not one each side. Because there are an even number of cell groups, both are on the same side of the battery.
From your complete set of measurements with the black probe on the grey wire, we can see that the most negative is -1.5V on the terminal with the two black wires, and the most positive is red at 16.1V. So your supposedly 36V battery, which should be 42V when fully charged is at 17.6V.
That is why it won't charge: it is at too low a voltage for the BMS to recognise.
If we now put those voltages in order, shift them by 1.5V which is what you would measure if the black probe was on the two black wires, and calculate the differences:
-1.5 0 1.5 3.0 4.6 6.2 8.1 10.1 12.1 14.1 16.1 (0 is grey to grey)
0 1.5 3.0 4.5 6.1 7.7 9.6 11.6 13.6 15.6 17.6
1.5 1.5 1.5 1.6 1.6 1.9 2.0 2.0 2.0 2.0
So, a very flat battery, somewhat unbalanced, but all cell groups in the same ball park i.e. no completely flat ones.
Probably just neglected for years, and gradually flattened by BMS consumption, so possibly no other fault. Cells sitting so low may have lost capacity, so even if you can recover it, it may not perform well. But maybe worth a try.
The cells need to be charged to a voltage the BMS is happy with, using a method not involving the BMS, and this needs to be st very low current because of the low state of charge.
One way is to charge each cell group individually, using an old 0.5A 5V phone charger. Bring each cell group up to say 3.3V, so 33V total, and then see if normal charger will then work.
Another way is to use a bench power supply with controllable current and voltage to charge the whole battery. Set current to say 0.2A, and voltage to say 33V.
Either way, this is a manually controlled process, with risks of overcharging cells if they are left on for too long. Not to be attempted unless you are sure of what you are doing.
Does this help?
Fuses are optional - sometimes one, sometimes two, sometimes none.
Thank you Mathew.
This is very helpful and informative.
It off a Carrera Vulcan ex display
so I would guess it’s been left on the bike and never charged.
I would like to have a try at method One
(One way is to charge each cell group individually, using an old 0.5A 5V phone charger. Bring each cell group up to say 3.3V, so 33V total, and then see if normal charger will then work.)
I have a draw full of different types of old chargers I will dig them out and find one that is 0.5A 5V.
How long would you think to safely leave each cell group to charge for ?
(I will not leave it. Unattended )
How would I connect to each cell group and how do I work out which wires to connect to for each cell group ?
This is very helpful and informative.
It off a Carrera Vulcan ex display
so I would guess it’s been left on the bike and never charged.
I would like to have a try at method One
(One way is to charge each cell group individually, using an old 0.5A 5V phone charger. Bring each cell group up to say 3.3V, so 33V total, and then see if normal charger will then work.)
I have a draw full of different types of old chargers I will dig them out and find one that is 0.5A 5V.
How long would you think to safely leave each cell group to charge for ?
(I will not leave it. Unattended )
How would I connect to each cell group and how do I work out which wires to connect to for each cell group ?
Yes thanks assuming all the green wires are the multi coloured ones .
which are + positive on this diagram ?
but on my battery the central grey wire on the right side is a negative ?
My battery has no fuses I would think it’s a good plan to add some while it’s apart ?
If it’s saveable
And has no C-
The Charge and Discharge wires just connected all together to the BMS
If there is enough wire exposed, small crocodile clips. If not, maybe carefully remove a mm or two of insulation to make room.
Always remember these are connected to the cells, there must not be any possibility when you have finished of any accidental short circuits.
Each cell group sits between two of the small wires, one each side of the battery. Start by mapping them out, using the multimeter, so that you know which wires represent each cell group.
From the numbers I listed above, you are looking for 10 places where the voltage from one wire to the other is in the range 1.5 to 2.0 volts.
Start with black probe on the two black wires, and red probe on the grey. That should be 1.5V, and that is your first cell group.
Move the black probe to grey, and red probe to blue. That should also be 1.5V and is the second cell group.
And so on. By measuring and recording you can determine the order of the wires. You charge each cell group by connecting to the wires on its - and + ends, being very careful to get polarity correct.
At half an amp, it will take a few hours for each cell group, but you should check voltage frequently to make sure it is behaving as expected, especially for the first cell group.
Remember that half the cell groups have + on one side of the battery, and half have + on the other side. Check, check and check again, do not make mistakes.
Always remember these are connected to the cells, there must not be any possibility when you have finished of any accidental short circuits.
Each cell group sits between two of the small wires, one each side of the battery. Start by mapping them out, using the multimeter, so that you know which wires represent each cell group.
From the numbers I listed above, you are looking for 10 places where the voltage from one wire to the other is in the range 1.5 to 2.0 volts.
Start with black probe on the two black wires, and red probe on the grey. That should be 1.5V, and that is your first cell group.
Move the black probe to grey, and red probe to blue. That should also be 1.5V and is the second cell group.
And so on. By measuring and recording you can determine the order of the wires. You charge each cell group by connecting to the wires on its - and + ends, being very careful to get polarity correct.
At half an amp, it will take a few hours for each cell group, but you should check voltage frequently to make sure it is behaving as expected, especially for the first cell group.
Remember that half the cell groups have + on one side of the battery, and half have + on the other side. Check, check and check again, do not make mistakes.
Ok and just to try across One cell pack
which wire from the charger positive should I put to where
same with the negative ..
stick them onto the battery terminals with insulation tape I think will hold them temporarily.?
which wire from the charger positive should I put to where
same with the negative ..
stick them onto the battery terminals with insulation tape I think will hold them temporarily.?
Ok I understand be very careful will do .
I will just try the first one and see how it goes .
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