Help to fault find on a Carrera Battery

[Baz the balloon man]

The

Panasonic (aka Panny) PF cell, 2900mah rated for 10a but typically for a longer life use at a max of 6 -7a per cell. It is a very good cell.

Like the Sam 29E one of the most prolific cells used for batteries.

The Bird Bike battery is knackard not holding a charge and just crashes once any load is put on it probably the reason it went back to Halfords under warranty.

I have a chap interested in buying the bike without a working battery , I have advised him to just buy a new one from Ali Express but the adds I found have disappeared.

So now trying to find a reputable company to re cell it for him .
Any recommendations ?
or which industry accreditation should they have ?

I have advised him and many others now asking me for advise on e bay to join this Forum .

Cheers
Baz

 

[saneagle]

The


The Bird Bike battery is knackard not holding a charge and just crashes once any load is put on it probably the reason it went back to Halfords under warranty.

I have a chap interested in buying the bike without a working battery , I have advised him to just buy a new one from Ali Express but the adds I found have disappeared.

So now trying to find a reputable company to re cell it for him .
Any recommendations ?
or which industry accreditation should they have ?

I have advised him and many others now asking me for advise on e bay to join this Forum .

Cheers
Baz

Re-celling a battery is very expensive. Are you sure you can't find a replacement battery on Aliexpress?

 

[Baz the balloon man]

Re-celling a battery is very expensive. Are you sure you can't find a replacement battery on Aliexpress?

they where being advertised around £180.00 including delivery but the ads have gone.
iI just e mailed the main manufacturer in China to see if I can purchase directly.

However a couple of the companies on e bay have both said they suspect it may just be one cell group that has failed could be as little as £60.00 quid after a full test. To get it going again

or from £200.00 to re cell with a branded cell’s then upwards of that depending on which cells they use Which is fair enough considering cost of a replacement from china if they then offer a warranty .

I have left it with the potential buyer to do as they wish , the current battery has enough to test the bike out. But in true e bay style they have gone quite gumtree is a waste of time too I used to sell lots of vans on there.

we are off to Vietnam at the end of the week so I will sort it all when we get home if it does not sell before we go.

passing through China I may stop on the way home and buy some bits .
Guangzhou seems to have a lot of electronic companies.

Giant now have a factory in Vietnam too !!

A Bird bike battery LOL and a

 

[matthewslack]

I suspect there is no such thing as accreditation for recelling an ebike battery.

 

[Baz the balloon man]

You've learnt a lot and not burnt the house down! And remember the cells may well be severely substandard from years of sitting flat, so not necessarily much lost.

Hi Mathew
I am home from VN now and back to bike building.

I was looking at some u tube videos on how to reset battery cells that have vented.

So I tried it out on the 3 cells from the Carrera battery you where helping me wake up that I over charged and are now separated from the battery Pack.

I used the blunt end of a punch to tap in the button end carried out the work in the garden with gloves , overalls and a face shield for PPE.

It has worked I think ! as the cells are now showing voltage of 4.2 however they should only be 3.5 V
I am thinking of bringing the voltage down bridging a small led bulb across each cell unless there is a simpler way to do this ?
.
The other cell groups in the Battery are holding a charge well Two months now sitting on my bench although I have not tested them under pressure ie powering a motor.

I am going to put it all back together and I now have the correct original charger .

Or I may buy 3 new cells if you think the ones I blew are not to be re used ?

Cheers
Baz

 

[Baz the balloon man]

You need a welder and some nickel strip. You can get the welders fairly cheap from Ebay, Aliexpress and Amazon. Search for 18650 welder:
Cheap Battery Spot Welder 18650, Yes its awesome!

Hi Mate

18650 welder on e bay just around £20.00 are these what you mean as they are very cheap ?

I am going to try put a new cell group in my Bird Bike battery as well as continuing to try fix the Carrera one I blew so do not mind going for a better quality to start with .

Cheers
Baz

 

[saneagle]

T

Hi Mate

18650 welder on e bay just around £20.00 are these what you mean as they are very cheap ?

I am going to try put a new cell group in my Bird Bike battery as well as continuing to try fix the Carrera one I blew so do not mind going for a better quality to start with .

Cheers
Baz

The £20 welders are a bit hit and miss, and there's a bit of a knack to using them. The more you pay, the better they are. Watch some YouTube video reviews to choose one; and if your strip isn't pre-slotted, cut slots with a pair of scissors to force the current through the strip, not across it.

 

[Baz the balloon man]

Ok will do ,
I was thinking around £50.00 ish for something a little better I see they also have the 18650 numbers on more expensive models.
I do not usually buy the cheapest tools u get what you pay for but on the other hand I do not need a professional workshop quality one yet any way that will cost hundreds if not more .

Any recommendations -as to a brand ?

 

[saneagle]

Ok will do ,
I was thinking around £50.00 ish for something a little better I see they also have the 18650 numbers on more expensive models.
I do not usually buy the cheapest tools u get what you pay for but on the other hand I do not need a professional workshop quality one yet any way that will cost hundreds if not more .

Any recommendations -as to a brand ?

I have one of these. It can do acceptable welds, but not very consistent. There's a bit of a knack to using it. You need to hold the probes at just the right pressure.

https://www.amazon.co.uk/Battery-Portable-Machine-Adjustable-Soldering/dp/B0C6T8KZZF?th=1

It's cheaper from Aliexpress and Banggood:

Excellway 5000W Mini Spot Welder High Power Handheld Spot Welding Machine for 18650 Battery Welding Tools for 0.1/0.15/0.2/0.25mm Nickel Strip 0-800A Current Adjustable

Only US$46.99, buy best Excellway 5000W Mini Spot Welder High Power Handheld Spot Welding Machine for 18650 Battery Welding Tools for 0.1/0.15/0.2/0.25mm Nickel Strip 0-800A Current Adjustable sale online store at wholesale price.

uk.banggood.com

 

[matthewslack]

Hi Mathew
I am home from VN now and back to bike building.

I was looking at some u tube videos on how to reset battery cells that have vented.

So I tried it out on the 3 cells from the Carrera battery you where helping me wake up that I over charged and are now separated from the battery Pack.

I used the blunt end of a punch to tap in the button end carried out the work in the garden with gloves , overalls and a face shield for PPE.

It has worked I think ! as the cells are now showing voltage of 4.2 however they should only be 3.5 V
I am thinking of bringing the voltage down bridging a small led bulb across each cell unless there is a simpler way to do this ?
.
The other cell groups in the Battery are holding a charge well Two months now sitting on my bench although I have not tested them under pressure ie powering a motor.

I am going to put it all back together and I now have the correct original charger .

Or I may buy 3 new cells if you think the ones I blew are not to be re used ?

Cheers
Baz

I take a cautious approach to safety, and where potential consequences are high, a very cautious approach.

Cells that have vented, or some other protection mechanism has triggered are telling you something! If their type leads you to a datasheet or test documentation, it will almost certainly say that such cells are not to be reused. The protection mechanism is only designed to fail safely. It is not designed for reset and reuse. Follow the cell manufacturer's guidance.

Replacing a few cells in a cell pack? I don't think I would ever do this either. The history of your battery would make me doubt its state i.e. potential for serious reduction in capacity because of long term stored flat. For my use cases, a low capacity battery is of no use, so I would not waste the effort.

I would also be concerned for possible issues arising from mismatch between new and existing cells, and the possibility of it ending up with a different user who did not know its history.

I would scrap the vented cells, buy new battery, possibly harvest cells for torches.

 

[Nealh]

Cell venting is for a reason and as said a fail safe mechanism.
4.2v is a max SOC for a lion cell.

Any messing about with cells and using force on them to manually vent them is a cause to bin them, don't follow idiot advice from numpty u tube posters.

 

[Baz the balloon man]

Ok will do I did not want to use them just thought to check , I will put them in the recycling.

I have found exact matching cells same make and capacity I will order 3 new ones .

I would not pass this Carrera battery on just using it to train really , I have a 700c Crossfire that I will change the kit from my old Giant /Yose kit , to use as I need better suspension my Arthritis is getting worse then if I can get the battery working I will fit it to work with the small frog I have once I get the correct piece of kit from Top bike to do this .
Provided I can get a suitable BMS and actually get it to function correctly if it the BMS does not function now I have the correct charger

no rush though

Think I will need to get a legal throttle to if the Arthritis keeps getting worse in my Knees which it is .

I just woke up another Carrera battery the 5 pin canbus one that looks new too the Vengence had been in storage for Two years I can see it’s never been used and the chap I bought it from blew the fuse on the BMS trying to put 12 V charge into it but it’s not holding the charge .

selling the other e parts on e bay.