Corroded a New Chamrider E-bike Battery and Warranty Lie

[nad]

Hi everyone,

I bought a Chamrider 48V18.6AH ebike battery on the last black friday from Aliexpress(their official seller). I'm posting this to warn others about Chamrider seller and look for a way to fix it.

Because of the long winter, I could have mounted it to use in April on my bike. I chose this brand because I saw good comments about the brand before buying it and they offer a 12-month warranty on the product page. Also, it has Samsung 29E cells.

When I wasn't using the battery, I checked the charge level from time to time and made sure it was above 50 percent. After the first full charge, it started to turn itself off after using it for a while. It got worse after each charge. It shuts down itself even just after a full charge now. I fully charged it 5-6 times only, it's no longer usable now.

When I mentioned about this to the seller, he only offered a discount for the new battery. But, when I mentioned that I recommended him to my supervisor for his bikes but stopped him because of the problem, he offered to send a new battery for free.

I also sent him the photos of the problem, the problem is some of the cells are corroded in the battery. This is causing the voltage imbalance, that group is 3.4v while others are 4v. I think the product waited too long time on the shelf. When it arrived, I did not open the battery because I had never opened a battery before and wasn't expecting this problem could happen on a new battery. So, I couldn't request a refund from Aliexpress because 15 days have passed since the delivery time.

By now, he said he sent the battery 2 separate times for free, but when I asked for the tracking number, he just stalled me. He never sent the new battery, he lied. He hasn't done anything so far for a solution. Then he asked me to pay the price difference for a new battery, and I accepted. After that, he increased the price difference and I accepted again. But he did nothing. Now, by stating that the similar battery(48V17.5AH) is out of stock, he tries to direct me to pay the price difference of much more expensive batteries that are too big/heavy for my bike I never need it. Also, in the meantime, he still kept asking me to buy 2 new batteries from him till now.

I have been in contact with the seller for more than a month, but I could not get any results from the warranty. He only stalls me. I couldn't even use the battery I bought, my bike is unrideable due to the battery problem.

Seems like I wasted about 200$ for the battery. Is it possible to fix the battery by replacing corroded cells? If so, should I buy the same spec cells with Samsung 29E(I couldn't find it in stock)
Nominal Capacity: 2850mAh and Continuous Discharge Rating: 2.75A

 

[eMark]

I bought a Chamrider 48V18.6AH ebike battery ... it has Samsung 29E cells. Nominal Capacity: 2850mAh and Continuous Discharge Rating: 2.75A

Did you do your due diligent figuring before purchasing that Chinese battery ...

6p x 2.850mAh = 17.1 Ah
7P x 2.850mAh = 19.95 Ah

18.6Ah ÷ 5p = 3,720mAh cell capacity
18.6Ah ÷ 6p = 3.100mAh cell capacity
18.6Ah ÷ 7p = 2.657mAh cell capacity

(29E) = 2.75A x 7p = Continuous Discharge Rating of 16.5A and 18.8Ah Capacity

There's a reason Chinese Li-ion ebike batteries are less expensive and a 1yr warrantee can be: iffy, risky (a crap shoot)

__________________________

https://em3ev.com/wp-content/uploads/2016/05/logo-300x54.png

Suggestion: ... 48V EM3ev Jumbo Shark Ebike Battery | EM3ev

 

[nad]

Did you do your due diligent figuring before purchasing that Chinese battery ...

6p x 2.850mAh = 17.1 Ah
7P x 2.850mAh = 19.95 Ah

18.6Ah ÷ 5p = 3,720mAh cell capacity
18.6Ah ÷ 6p = 3.100mAh cell capacity
18.6Ah ÷ 7p = 2.657mAh cell capacity

(29E) = 2.75A x 7p = Continuous Discharge Rating of 16.5A and 18.8Ah Capacity

There's a reason Chinese Li-ion ebike batteries are less expensive and a 1yr warrantee can be: iffy, risky (a crap shoot)

__________________________

https://em3ev.com/wp-content/uploads/2016/05/logo-300x54.png

Suggestion: ... 48V EM3ev Jumbo Shark Ebike Battery | EM3ev

Unfortunately, I didn't. I decided to convert my bike on black friday. So, I researched and bought the motor kit and battery in a bit rush to not miss deals.

If I knew these before buying, I would prefer Samsung 35E. They were selling 35E too, but I didn't know the difference.

Since my motor kit's(500w geared hub) peak was around 800w on a full charge, I thought the battery should be fine. 800w/48v=16.6a

 

[eMark]

If the figures don't add up and it sounds too good to be true it's most likely false advertising (48V 614.4Ah) ...

https://static.wixstatic.com/media/f031ed_00a6b5b2f41f446d8195c3ee05975519~mv2.png/v1/fill/w_500,h_500,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/f031ed_00a6b5b2f41f446d8195c3ee05975519~mv2.png

High Capacity E-bike Battery (614.4 AH, 48V) | GIN e-bikes

Introducing the Extra Battery for your GIN X e-bike - the perfect addition to extend your ride time and explore more with ease. With a powerful 614.4 WH and 48V capacity, this battery is designed with high-quality materials (Teslagrade cells) and technology, ensuring reliable and long-lasting...

www.ginebikes.com

Another error ... should read powerful 48V and 14.4Ah capacity (more likely). Maybe 614.4Wh ?

 

[nad]

If the figures don't add up and it sounds too good to be true it's most likely false advertising (48V 614.4Ah) ...

https://static.wixstatic.com/media/f031ed_00a6b5b2f41f446d8195c3ee05975519~mv2.png/v1/fill/w_500,h_500,al_c,q_85,usm_0.66_1.00_0.01,enc_auto/f031ed_00a6b5b2f41f446d8195c3ee05975519~mv2.png

High Capacity E-bike Battery (614.4 AH, 48V) | GIN e-bikes

Introducing the Extra Battery for your GIN X e-bike - the perfect addition to extend your ride time and explore more with ease. With a powerful 614.4 WH and 48V capacity, this battery is designed with high-quality materials (Teslagrade cells) and technology, ensuring reliable and long-lasting...

www.ginebikes.com

Another error ... should read powerful 48V and 14.4Ah capacity (more likely). Maybe 614.4Wh ?

I couldn't understand completely. But, yes, probably there is false advertising.

There are 78 cells. 78x2.75=214.5 probably I'm missing something in the calculation.

Without throwing out this battery, is it possible to fix it by replacing corroded cells?

 

[amberwolf]

Ah (and A) only add for paralleled cells. Series cells only add voltage.

There's been a trend by the professional liars in marketing for "phone/tablet powerpacks" and "car starters" to just add up all the cells regardless, and then just add some more on top to make it sound better, and use that gigantically inflated number as the pack capacity, even though it is a complete lie. Wouldn't surprise me to see this happen with every other kind of battery pack, making it impossible to know what the pack can *actually* do.

So anytime you see a seller advertising improbably large numbers for things like Ah or Wh, it's probably safer to assume they're lying and you shouldn't buy anything they sell.


For repairing the existing pack:

If you can test the other cells to be sure they're ok...but is it corrosion from an external source, or leakage from ruptured cells?

If it's just corrosion, then as long as you can verify there's no other corroded cells, replacing the failed ones (possibly including those in parallel with them to be sure they aren't damaged from being drained by internal failures of the corroded cells) may let the pack function something like it was intended to.

If it's actually leakage from ruptured cells, there's a couple of likely causes. One isn't so bad, as long as you find all the damaged cells and replace them--bad spot welding punching thru the cans. But the other is if the pack is built from recycled cells salvaged from other failed packs (not uncommon in the cheap stuff, and happens even in the pricey ones), they may have ripped the old tabs off and torn holes in the cell casings--some of the holes might be very small and some very large, with teh larger ones leaking now and the others doing so later. If this is the case you can't see the holes unless you remove the interconnects (tabs / strips) between all the cells on both ends, which you can't just peel off or you leave holes of your own behind...and this will mean having to completely rebuild the battery from scratch, which makes it probably not worth doing.

So...if it's the second cause once you get into it, on the already failed cells (where you see holes or remains of welds in the cell ends that *are not* from the present pack build (don't line up with the welds on the strips you remove from the failed cells), it's likely the whole pack is built that way out of recycled cells, which could have been literal garbage scrapped as failed already, and just reused to build packs and sold as if they were new (happens all the time).

 

[nad]

Ah (and A) only add for paralleled cells. Series cells only add voltage.

There's been a trend by the professional liars in marketing for "phone/tablet powerpacks" and "car starters" to just add up all the cells regardless, and then just add some more on top to make it sound better, and use that gigantically inflated number as the pack capacity, even though it is a complete lie. Wouldn't surprise me to see this happen with every other kind of battery pack, making it impossible to know what the pack can *actually* do.

So anytime you see a seller advertising improbably large numbers for things like Ah or Wh, it's probably safer to assume they're lying and you shouldn't buy anything they sell.


For repairing the existing pack:

If you can test the other cells to be sure they're ok...but is it corrosion from an external source, or leakage from ruptured cells?

If it's just corrosion, then as long as you can verify there's no other corroded cells, replacing the failed ones (possibly including those in parallel with them to be sure they aren't damaged from being drained by internal failures of the corroded cells) may let the pack function something like it was intended to.

If it's actually leakage from ruptured cells, there's a couple of likely causes. One isn't so bad, as long as you find all the damaged cells and replace them--bad spot welding punching thru the cans. But the other is if the pack is built from recycled cells salvaged from other failed packs (not uncommon in the cheap stuff, and happens even in the pricey ones), they may have ripped the old tabs off and torn holes in the cell casings--some of the holes might be very small and some very large, with teh larger ones leaking now and the others doing so later. If this is the case you can't see the holes unless you remove the interconnects (tabs / strips) between all the cells on both ends, which you can't just peel off or you leave holes of your own behind...and this will mean having to completely rebuild the battery from scratch, which makes it probably not worth doing.

So...if it's the second cause once you get into it, on the already failed cells (where you see holes or remains of welds in the cell ends that *are not* from the present pack build (don't line up with the welds on the strips you remove from the failed cells), it's likely the whole pack is built that way out of recycled cells, which could have been literal garbage scrapped as failed already, and just reused to build packs and sold as if they were new (happens all the time).

Thank you for the clear explanation!

Since I will only use this battery for one year, I wanted to go cheap.

I think I should remove that group and measure the cells separately first. If I do it, I will need to reconnect/weld nickel strips with another strip line. And, I think I can't peel it off properly, so checking the old holes may not be possible.

As for replacement cells, what should I pay attention to if I can't find the same 29E cells? Would it be okay if it has a higher or equal constant discharging current and the same capacity?

By the way, when removing the cells, I should break black plastics on one side and desolder the red wire, right? Then, I will need to push the group from the other side. Sorry for asking these, I have never worked on batteries before, and they scare me because of the risk of explosion. Therefore, I could not even open the battery case indoors, I will probably do all the future processes outdoors.

And for welding, will this work?

https://www.aliexpress.us/item/3256805065500632.html?

 

[eMark]

I couldn't understand completely. But, yes, probably there is false advertising.

There are 78 cells. 78x2.75=214.5 probably I'm missing something in the calculation.

78 cells is 13s6p ... 18.6Ah ÷ 6p = 3.100Ah cell capacity; however new 29e cells at most 2.850Ah ... 6p x 2.850Ah = 17.25Ah x 48V = 828Wh (avg). Continuous discharge is 6p x 2.75A = 16.5A rating ... 20A BMS with only a 15amp Controller.

Who's ever heard of an ebike with a 48V Battery, but not even a 20amp Controller. You should have purchased a 13s6p battery with 35e cells (20.1amp Continuous Discharge)

Without throwing out this battery, is it possible to fix it by replacing corroded cells?

Yes, it's always possible ... BUT is it worth the effort/risk for someone with no previous DIY battery building experience ???

I feel for your dilemma (between a rock and a hard place). You could spend more dollars, time consuming labor, frustration (maybe giveup) and still not endup with a trustworthy battery.

 

[tomjasz]

29e cells

the longest pack life of any of my previous cells. new 21700 and a 35e pack being used. we’ll see.