BMS fitting to Carrera Battery

[Baz the balloon man]

Hi all especially the experts .

Looking for some advise on a battery for my own personal use.

I have had another battery sent to me that some one opened and messed up that I have now bought as scrap .

It’s the Carrera Battery that was made in Taiwan the one the Joycube battery should be able to replace on Carrera bikes with EBCT19 controllers.

I think the only comms wires are battery level indicators as I have been told this function does not work when the replacement after market Joycube Carrera Battery is used. Not sure if this is fact

I have balanced the battery back to 40V using the method Mathew taught me when I first joined all cell groups are equalled at 4V.

I have had the battery working and turning a Suntours motor on a KT controller and LCD.

However the BMS which lights up still refuses to allow the battery to charge using the correct original charger.
But it will charge in a balanced way from the direct charging terminal’s .

I am going to put an after market BMS on it and have found this on photos attached on e bay .

I am hoping to be able to wire the on and off switch wires onto the original on and off switch PCB and isolate the wires that will no longer be needed unless there is a better way ?

If this will not work I will fit an on and off switch.

Please see photo of new BMS specifications can any one tell me why this is or would not be a suitable replacement for a battery for my bench test set up ?

If it’s not a suitable BMS for this battery pack any advice on a more suitable one would be appreciated.

 

[Baz the balloon man]

Oh forgot to mention I have tried to contact the manufacturer in Taiwan to see if original replacement BMS boards are available this is my second attempt but they are ignoring my attempts to contact them .

These batteries are not glued closed like the current Carrera ones are .

 

[saneagle]

Oh forgot to mention I have tried to contact the manufacturer in Taiwan to see if original replacement BMS boards are available this is my second attempt but they are ignoring my attempts to contact them .

These batteries are not glued closed like the current Carrera ones are .

Cheap BMSs are a bit hit and miss. I've had some that were OK, then bought another the same, which dained a cell-group down, so if it's for your own bike, always check afterwards that it does what it's supposed to do, and I'd probably get a bluetooth one so that I could check it easily.

I can't advise which is the best, but what I can say is to be careful with the ribbon cable connectors. They're all wired differently, and sometimes back to front, so make sure you check voltages before plugging in a connector that fits.

 

[Baz the balloon man]

Cheap BMSs are a bit hit and miss. I've had some that were OK, then bought another the same, which dained a cell-group down, so if it's for your own bike, always check afterwards that it does what it's supposed to do, and I'd probably get a bluetooth one so that I could check it easily.

I can't advise which is the best, but what I can say is to be careful with the ribbon cable connectors. They're all wired differently, and sometimes back to front, so make sure you check voltages before plugging in a connector that fits.

Thanks What I not sure about is the BMS Amps needed for this battery pack ?

Or are more Amps just safer as higher Amps BMS like for like cost more ?

So plan is I will map it out and match the different colours to the new BMS wires first .
if the plug is not compatible then work out from the live or ground wire matching the colours.

On this pack the polarity of individual wires changes ie left side green can be + or - depending on which terminal it’s connected to on the right side so how do I check the voltage of the balance wires and match to the ones on this pack ?

What sort of money or brand would you consider to be a good BMS I have looked on Topbikekit but again unsure of quality and suitability I am not worried about spending a bit more

 

[saneagle]

Thanks What I not sure about is the BMS Amps needed for this battery pack ?

Or are more Amps just safer as higher Amps BMS like for like cost more ?

So plan is I will map it out and match the different colours to the new BMS wires first .
if the plug is not compatible then work out from the live or ground wire matching the colours.

On this pack the polarity of individual wires changes ie left side green can be + or - depending on which terminal it’s connected to on the right side so how do I check the voltage of the balance wires and match to the ones on this pack ?

What sort of money or brand would you consider to be a good BMS I have looked on Topbikekit but again unsure of quality and suitability I am not worried about spending a bit more

I use a BMS that allows 5A more than the controller, so 20A controller 25A BMS. The BMS needs enough headroom not to trip at the controller's maximum current, and it needs to give protection against anything that would cause over-current, like a jammed motor, damaged cable or short circuit. Also, it needs to ensure that the cells are not allowed to be driven too hard considering their specification.

As a general rule, I look up the max continuous current of the cells, multiply it by however many there are in parallel and divide it by 2 for safety and long life, then I make sure that the controller doesn't allow more current than that abd the BMS has 5A headroom over the controller.

EXample: Cells have max continuous current 10A; 4 cells in parallel, so 40 cell 36v pack.

max current to run the pack = 4 x 10 ÷ 2 = 20A, so 20A controller, 25A BMS.

This is just my rule. It's not an exact science.

 

[Baz the balloon man]

Or Plan B as a hobby is to add these first pack to the ones in photos attached which includes the first pack I blew .

And make myself a nice big 48V rear rack battery for my Arrary getting a suitable BMS that suits a build from scratch instead of trying to work out how to match an old carrera to a BMS it just a lot of work stripping them down .

I see both Panasonic 18650s and The Samsung 18650s are used in Carrera Battery’s are they compatible as a few on here have said not to mix different brand cells even if they are the same

 

[Baz the balloon man]

Has any one used theses for a DIY battery build saw them on e bay look ok to me for a rear rack build no spot welder available?

 

[Baz the balloon man]

Cheap BMSs are a bit hit and miss. I've had some that were OK, then bought another the same, which dained a cell-group down, so if it's for your own bike, always check afterwards that it does what it's supposed to do, and I'd probably get a bluetooth one so that I could check it easily.

I can't advise which is the best, but what I can say is to be careful with the ribbon cable connectors. They're all wired differently, and sometimes back to front, so make sure you check voltages before plugging in a connector that fits.

Looking on Topbikekit at these attached the Blue tooth for the 48v rear rack build and the other for the old Carrera battery what do you think or would you pick something else from them ?

The other blue tooth models are a bit expensive for an old battery pack that’s had problems unless a USB port one has similar functionality?

 

[saneagle]

Or Plan B as a hobby is to add these first pack to the ones in photos attached which includes the first pack I blew .

And make myself a nice big 48V rear rack battery for my Arrary getting a suitable BMS that suits a build from scratch instead of trying to work out how to match an old carrera to a BMS it just a lot of work stripping them down .

I see both Panasonic 18650s and The Samsung 18650s are used in Carrera Battery’s are they compatible as a few on here have said not to mix different brand cells even if they are the same

It's generally not a good idea to mix different types of cells, nor should mix cells of a different age or condition.

 

[saneagle]

Has any one used theses for a DIY battery build saw them on e bay look ok to me for a rear rack build no spot welder available?

How are you going to mount a battery like that, and what are you gong to put it in?

 

[saneagle]

Looking on Topbikekit at these attached the Blue tooth for the 48v rear rack build and the other for the old Carrera battery what do you think or would you pick something else from them ?

The other blue tooth models are a bit expensive for an old battery pack that’s had problems unless a USB port one has similar functionality?

There are a load of cheap bluetooth BMSs on Aliexpress, but be careful because for some you have to buy the bluetooth box seperately. Always reas the reviews because some don't do what they're supposed to and some have secret passwords, etc.

 

[Baz the balloon man]

How are you going to mount a battery like that, and what are you gong to put it in?

Not sure have not got that far yet , just thought to get some opinions on the system for DIY builds .
Be interesting to then see what would work for a case or is there an exsisting rear rack case that would work.

What I like about it is the ease to change defective cells especially if using salvaged in the first place.

But if I had to make a case my first thought would be fiberglass . Or even liquid rubber for an outer skin.

 

[Baz the balloon man]

There are a load of cheap bluetooth BMSs on Aliexpress, but be careful because for some you have to buy the bluetooth box seperately.

On the old Carrera battery I think to only spend around £20.00 because of its age , it must be at least five years old it’s had problems ie out of balance and some one has tried unsuccessfully to recharged it.

On the other hand a decent quality one could always be salvaged and used again .

What u pay is what you get somtimes.

I sent an e mail to Topbikekit to see what or if they will recommend any of there BMS boards .