Bad chinese battery experience ( daoji666 ) beware!

[MalcolmW]

36V 10AH LIFEPO4 Lithium Battery electric bicycle bike

Bought though ebay. Failing cell after one charge. Will repair if I send it back at a cost of £74. I only paid £160 with a charger. I don't want to send good money after bad

"Theres no fool like an old fool."

If anyone has a similarly failed life battery I would be interested in buying their remains to repair mine and try to get some use out of it.

Malcolm

 

[Deleted member 4366]

It's most likely just a wire off or a bad connection somewhere, which should be repairable. Which cells does it have? or give us a link to the battery.

 

[MalcolmW]

d8veh,

36V 10AH LIFEPO4 Lithium Battery electric bicycle bike | eBay

I will post some detailed measurements tomorrow

Malcolm

 

[Deleted member 4366]

It isn't heavy enough for 18650 cells, so that's good news. Hopefully pouches. You need to peel off the duct tape to get at the cells,then you can check which, if any, are not connected. What's the symptoms that tells you something's wrong?

 

[xonath]

Does not ebay protect the buyer?

I would lodge a complaint with ebay for a refund. explain the issue, and say the item is available by collection for the seller to arrange pickup at their expense.

Ebay in most cases when an item is posted protects the buyer and while the case is in dispute I believe from an issue I had that the sellers paypal account suddenly has the amount of the battery locked out from them to draw on until the dispute is settled. You may win, nothing to lose really.

But, if the battery can be fixed first go that route as i think you want the battery not the cash.

Kev

 

[Deleted member 4366]

You're correct that Paypal gives you a level of protection. However, its little help for faulty Chinese items. Their terms and conditions are that they will refund what you originally paid after you've returned the item to the supplier at your expense. just to make it clear, they don't refund the return postage. I know this because I received some goods that were damaged in transit, so I had to go through the process. Luckily, I got DHL to agree to return the goods free of charge because it was them that damaged them, so I got all my money back.

 

[electric_avenue]

Also be aware that once you've tampered, the seller will not be obilged to accept it back.

 

[lemmy]

You're correct that Paypal gives you a level of protection. However, its little help for faulty Chinese items. Their terms and conditions are that they will refund what you originally paid after you've returned the item to the supplier at your expense. just to make it clear, they don't refund the return postage.

Talk about a hostage to fortune! That would make buying from China an absolute 'not do' for me.

I'm glad DHL agreed to return the item - can you be sure the Chinese won't charge you for despatch of the new one, though?

 

[Deleted member 4366]

Talk about a hostage to fortune! That would make buying from China an absolute 'not do' for me.

I'm glad DHL agreed to return the item - can you be sure the Chinese won't charge you for despatch of the new one, though?

I've bought more than a hundred items from China - some low cost and many expensive. You're right that there's a risk: However, you have to be philosophical about it. You save a lot of money on each item. eventually something might go wrong and you lose a bit, but compared with what you already saved, you're still ahead. Fortunately, I only had one transaction go wrong, and it was quite a lot of hassle to sort it, but in the end I got all my money back for that one.
I've found the Chinese traders generally to be honorable. There are some crooks there like everywhere, but, if they accept Paypal, there's a fair chance that they're honest.
General advice: Never buy branded items at what appears to be low prices because they'll most likely be counterfeit.
Back to topic. Malcom, I think you'll have to accept what you've got. It would be worth telling the supplier about it just in case he wants to share the responsibility for it, but most likely he'll just say that it was tested OK before he despatched it. You have to bear in mind that he probably has a lot of customers that haven't a clue, and they damage their batteries somehow. I suspect that yours got bumped about a bit in transit and a wire's come off somewhere. Cells don't normally "die" on their own when new. The only way I've seen one die was when it was discharged to 0v, which can't normally happen in a short time.
There's lots of possibilities for what's wrong with you battery. Most of them are easy to sort as long as you can solder and use a voltmeter, but you haven't given us much to go on to help you.

 

[lemmy]

You save a lot of money on each item. eventually something might go wrong and you lose a bit, but compared with what you already saved, you're still ahead.

Good point. I was only thinking of an expensive 'one off'.

 

[MalcolmW]

It isn't heavy enough for 18650 cells, so that's good news. Hopefully pouches. You need to peel off the duct tape to get at the cells,then you can check which, if any, are not connected. What's the symptoms that tells you something's wrong?

It seems likely that the problem has been there from day one, as I have only managed 14 miles, with assistance , for 3 cycles.

Details

5 year old Ezee Sprint originally with an 8 amphr NMHI battery.

I have measured the cell voltages at the BM this charge last cycle but not before

The BM cuts out at about 36 volts . At this time one is at 2.3V and the others are all about 3.3V. It would seem that this cell is causing cut off which is what should happen.

Recharging is quite quick as you would expect all cells are brought roughly the same except the bad one which is about 0.2 volts down.

It may be that the cells are badly out of balance and that I need to top up the odd one and try it. What I would like to know is do cell tend to balance out as per other chemistries or do they not?

 

[bode]

See this thread, all about these very batteries (some positive comments, a lot of negative):
http://www.pedelecs.co.uk/forum/electric-bicycles/7069-cheap-lipo4-china.html

 

[MalcolmW]

I've bought more than a hundred items from China - some low cost and many expensive. You're right that there's a risk: However, you have to be philosophical about it. You save a lot of money on each item. eventually something might go wrong and you lose a bit, but compared with what you already saved, you're still ahead. Fortunately, I only had one transaction go wrong, and it was quite a lot of hassle to sort it, but in the end I got all my money back for that one.
I've found the Chinese traders generally to be honorable. There are some crooks there like everywhere, but, if they accept Paypal, there's a fair chance that they're honest.
General advice: Never buy branded items at what appears to be low prices because they'll most likely be counterfeit.
Back to topic. Malcom, I think you'll have to accept what you've got. It would be worth telling the supplier about it just in case he wants to share the responsibility for it, but most likely he'll just say that it was tested OK before he despatched it. You have to bear in mind that he probably has a lot of customers that haven't a clue, and they damage their batteries somehow. I suspect that yours got bumped about a bit in transit and a wire's come off somewhere. Cells don't normally "die" on their own when new. The only way I've seen one die was when it was discharged to 0v, which can't normally happen in a short time.
There's lots of possibilities for what's wrong with you battery. Most of them are easy to sort as long as you can solder and use a voltmeter, but you haven't given us much to go on to help you.

I have given a bit more detail see below. Where would I go to by some cells to do a repair?, if it comes to that. Preferably not China.

Malcolm

 

[Deleted member 4366]

I have given a bit more detail see below. Where would I go to by some cells to do a repair?, if it comes to that. Preferably not China.

Malcolm

It depends what cells they are. The cylindrical ones are easy enough to get hold of and not too expensive, but I've never seen the pouches for sale. You might be able to get one from the seller. The battery in the last posts that Bode was referring to had 18650 cells in it, which I wouldn't buy because of the risk of damage in transit. I don't believe that yours has them, but you need to look inside. If the one cell goes up to only .2v less than the others (is that 3.4v and 3.6v?), the BMS is definitely charging it, so I'd try a couple more cycles to see what happens. Maybe it is a faulty cell, in which case the only sensible option would be to replace it.

 

[MalcolmW]

Feeling through the tape i guess their cylindrical. i am going to try the cycling without deep discharge approach and see how it goes before I take off the wraps. I have asked the supplier to send me some cells to repair it but its gone kind of quiet.

 

[aseb]

the pouches are available at BMSbattery.com as are large large cells but you need to identify what is in there first. If it's not spray coded onto the battery outer then it's size and shape should help identify it.
If it is a balance thing then leaving your charger on for 12 hours should get the BMS to do its thing. But that Voltage is a long way out......
Your BMS cut off at 36V? Is this a 36V battery? If so it is too high.