I should've read this forum before I bought my battery from sun-

elmobob · Nov 8, 2014

I should've read this forum before I bought my battery from sun-thing28 on ebay, I purchased mines for $369 a 20ah one. I plugged it in and the charger was showing green meaning it was ready, I found that to be strange since batteries usually come half way charged, I unplugged it and 2 weeks later my 500w motor and controller came in, when I plugged it in it was measuring 37v but was already showing low on the lcd display on thet bike kit, I rode it for a few yards and it turned off, I measured the voltage and it read 11.1v :roll:

I have left the battery overnight and its still measuring 11.1v when I disconnect the charger, the charger is putting out 44.6v. I emailed sum-thing28 today havent gotten a reply yet. I hope I can get it exchanged for another one. Any Ideas as to what my options are now?

arkmundi · Nov 8, 2014

elmobob said:
I should've read this forum before I bought my battery from sun-thing28 on ebay, I purchased mines for $369 a 20ah one. I plugged it in and the charger was showing green....

Correction: I should've read this forum before I bought ANYTHING. For all you noobs out there, its OK to be noobish. Even I'm noobish often enough, but less & less so as I build up knowledge & experience. Have to say thank you again to John in CR for talking me out of a stupid mistake after I made a purchase. Which I sent back for a full refund. Which I then used the money for a much better purchase. BEST ADVISE - read up, do some real research and make an informed decision before buying ANYTHING eBike or LEV related.

elmobob · Nov 8, 2014

I had a great Bionx 350 watt 9ah kit since 2008 (paid a hefty $1,700) but was reliable and gave me no problems. Since, the battery degraded to a few miles and ended up selling it recently then I thought it would be a good idea to buy a bigger 20ah battery with a 500w generic ebay kit for less $. I guess this is why I see many gas bicycle conversions and not so many electric conversions where I live, I do see the electric bikes the food delivery people use mostly in NYC, but those come already built with bike n all. I did a quick google search "Chinese LiFePO4 ebay battery review" to see if I there where any reviews of people buying these batteries but didn't see any negative or positive results just links to purchase them. My point is people should blog their experience more often with these batteries. I will certainly post my experience in as many places as possible if I can't get a refund or an exchange :evil:

, for $369 I definitely got what looks like a LiFePO4 battery manufactured many years ago that was sitting for so long the cells aged or some cell voltages are very low and cant take a charge, that or they put a shitty BMS on the pack.

amberwolf · Nov 8, 2014

elmobob said:
My point is people should blog their experience more often with these batteries.

There's plenty of experiences posted here on ES, and probably on other forums of this type like VisforVoltage, etc.

Some of them are just experience/complaint threads/posts, and some are complete reviews, and some are full troubleshooting/repair threads as well.

As for what's wrong, well, it could be a lot of things. If you can't get a refund or replacement, then if you're willing to open it up and check things we can probably help you fix it.

elmobob · Nov 8, 2014

amberwolf said:
As for what's wrong, well, it could be a lot of things. If you can't get a refund or replacement, then if you're willing to open it up and check things we can probably help you fix it.

Thanks amberwolf, I'm keeping my hopes that the ebay seller will do the right thing. Will keep you guys posted.

friendly1uk · Nov 9, 2014

Don't kick yourself for not asking first. Lots of people recommend this seller, despite the fact we have had half dozen such threads this month already. A much worse failure rate than bsmb who sell a whole lot more yet are thought of in a worse light. Too many folks seem blinkered to this fact, so you wouldn't of got consistent advice had you of asked. This is reflected in every thread about them. Every couple of days at the moment.

My money is on him replying after a few days, then sending you a different bms and going quiet on you. Don't dismay though, Lots of folks here will guide you.

dogman dan · Nov 9, 2014

It does appear that your battery won't charge, and likely the bms has been preventing the charging from happening.

The 11v is showing because the bms has now shut off the battery, since you rode some with very little charge on it.

Hopefully the guy will respond with a new bms for you. In another recent thread it took him weeks to respond. You have 14 days to send it back if you want to do that I think.

dnmun · Nov 9, 2014

you should determine why it is not working before you decide to make him take it back or to send you parts to repair it.

if you accept replacement parts and decide to install it yourself with absolutely no knowledge of what you are doing you will be in worse shape.

there is no evidence yet that it is defective. the only thing known is that you say it will not charge.

what is the voltage output on the charger? can you measure the battery voltage in the charging plug on the battery?

elmobob · Nov 9, 2014

dnmun said:
you should determine why it is not working before you decide to make him take it back or to send you parts to repair it.

if you accept replacement parts and decide to install it yourself with absolutely no knowledge of what you are doing you will be in worse shape.

there is no evidence yet that it is defective. the only thing known is that you say it will not charge.

what is the voltage output on the charger? can you measure the battery voltage in the charging plug on the battery?

This is not my first ebike conversion, I've done a few before for myself and other people, as I said before, voltage reading when the charger is disconnected directly from the battery is 11.1v the charger reads 44.6, same 44.6v when connected to the battery. I charged a friends 36v LiFePO battery and it had no problems doing so, the green light turned yellow and after a few hours green. Also I took my friends good 36v battery and hooked it up to my bike kit and was running around with no issues - he also got it from china a year ago from another ebay vendor. I might be a noob when it comes to diagnosing the issue with the BMS, but I have pretty good electrical knowledge, I've worked installing car stereos and amplifiers for a few years so I've done my share of splicing and soldering.

Here's an update, I get up this morning and measure the battery voltage, it reads 36.6v I said thats an improvement, I get exited, I plug it into my bike again and was able to run for a few minutes before It quit and again read 11v.

dnmun · Nov 9, 2014

expose the BMS and take a picture of it so we can show you where to measure the cell voltages.

elmobob · Nov 9, 2014

dnmun said:
expose the BMS and take a picture of it so we can show you where to measure the cell voltages.

That will be my last option if i'm SOL, i'm waiting for a reply from sun-thing28 hoping he agrees to exchange the battery or refund the money via paypal. Thanks

friendly1uk · Nov 9, 2014

He has no choice. If you start a Paypal dispute, Paypal will refund you and ask you to return it. Though your return costs are lost.

Mine also gives a low reading when the charge fet is not allowing power between the battery and charger. It's just a little leak. So small 3 meters here all gave a different reading. The meters themselves draining the leak away towards nothing. They were not analogue meters either

Buying batteries scares me. It's a huge part of the outlay, and one with such varied prices. It can be worth paying that bit more for known cells from a known supplier though. 50+ cells is not uncommon. Some finger maths tells us that if just 2% of cheap cells perform poorly, then your likely to get one. A pack is as good as it's weakest cell, so quality control is a real concern.

USAEBIKECO · Nov 10, 2014

I am still amazed people fall for the "low price" sun thing sells its batteries for. You wonder why the price is low?? Lessons learned.

The cost of shipping a battery back to china is a few hundred dollars.

Sun thing and other Chinese battery vendors have been scamming Americans with defective batteries for YEARS.

dnmun · Nov 10, 2014

but there is no evidence the battery is defective. it just appears to be unbalanced but the guy decided not to do the work to make it balance. he did not even open the BMS and expose it so we could tell him where to measure the voltages.

friendly1uk · Nov 10, 2014

dnmun said:
but there is no evidence the battery is defective.

While his testing has not exhausted every angle, it is more than enough to prove the pack is defective. Stripping it down to see what can be salvaged is unacceptable if he views this pack as a reject. It must go back as supplied. If he opens it without the sellers instruction, he owns it. You can't send something back once you have initiated repairs. It must go back as supplied

dnmun · Nov 10, 2014

no, he did not prove it is defective. he has presented no evidence the battery is defective. it will charge briefly until the BMS hits the HVC. he has done nothing to balance the pack so it will take a full charge. he has not even measured cell voltages at the BMS. he did not even post up a picture of the BMS so we can show him where to measure. there is no way he can claim he has a defective product until he proves it.

elmobob · Nov 10, 2014

dnmun said:
no, he did not prove it is defective. he has presented no evidence the battery is defective. it will charge briefly until the BMS hits the HVC. he has done nothing to balance the pack so it will take a full charge. he has not even measured cell voltages at the BMS. he did not even post up a picture of the BMS so we can show him where to measure. there is no way he can claim he has a defective product until he proves it.

Lets suppose you where to buy a new car from a dealer one day and as you drive out of the lot the engine blows a gasket, because you could would you go ahead and disassemble the engine to attempt to replace that gasket and risk the warranty or would you attempt to get a refund for it ? Same for a battery, no matter the chemistry it should come balanced and ready for use after a charge without the need for the consumer to be a battery expert.

As I said before, tearing up the battery to expose the BMS and measure the voltage at the cell level will be my last resort if sun-thing28 doesn't respond with an exchange offer and or paypal could not get me my money back.

Ykick · Nov 10, 2014

Well, rookie mistake #1 - these aren't cars and obviously you have little-to-no experience buying batteries directly from Chinese vendors. We do. But go ahead and do it how you "think/feel "it should be and see how that works out for you....

dnmun · Nov 10, 2014

nobody asked you to disassemble the battery. that is entirely made up by you. i asked you to take a picture of the BMS so we can show you where to measure the voltages. you do not have to take the battery apart to take a picture of the BMS.

in fact you do not have to do anything, but your battery is not defective. i was just trying to help you get it balanced so it would take a full charge but you refuse to do anything except blame someone else.

elmobob · Nov 10, 2014

Ykick said:
Well, rookie mistake #1 - these aren't cars and obviously you have little-to-no experience buying batteries directly from Chinese vendors. We do. But go ahead and do it how you "think/feel "it should be and see how that works out for you....

You're absolutely right, rookie mistake of mines to buy batteries from chinese vendors. This is how I feel, and now I'm in this forum to get advice.

StudEbiker · Nov 10, 2014

I'm still waiting for my battery from Sun-thing28. :|

The one thing I'm optimistic about is that so far none of the people complaining about the batteries they've received are able/willing to do even the most basic diagnostics on it before declaring they got a defective battery.

friendly1uk · Nov 10, 2014

dnmun said:
no, he did not prove it is defective. he has presented no evidence the battery is defective. it will charge briefly until the BMS hits the HVC.

The thread I'm reading has him riding to lvc then not being able to charge. What page are you on? How can you categorically tell him "your battery is not defective" and that he has hit HVC when nothing points to this. He has just been discharging the pack. That means all the cells were discharged a bit. How can one be sat at hvc levels.

People seem to think the bms is exposed for testing? He can't do any more than he has done. Is there really a suggestion here that this is not actually a battery, but rather a battery kit requiring minimal finishing?

NeezyDeezy · Nov 10, 2014

StudEbiker said:
I'm still waiting for my battery from Sun-thing28. :|

The one thing I'm optimistic about is that so far none of the people complaining about the batteries they've received are able/willing to do even the most basic diagnostics on it before declaring they got a defective battery.

Actually, I did extensive diagnostics, I just didn't type it out on the forum.

dnmun · Nov 10, 2014

what did you do to diagnose the problem you said you had with your battery? you never mentioned this before so it would help if you posted up the data.

USAEBIKECO · Nov 10, 2014

elmobob,

My advice is to open a PayPal case against sun thing immediately. Then make sun thing pays for the repairs, or shipping the battery back to China.

FYI - shipping a battery back to China is extremely difficult and expensive. You may not be able to ship it back at all.. Sun thing knows this, and that's why he and other Chinese vendors sell defective batteries to inexperienced Americans. They have been doing this scam since at least 2008 when I first got into ebiking. I know this first hand dealing with V-power.

Also, if you end up losing money make sure to leave negative feedback on ebay. Warn others of their defective batteries. Don't let them take your money and screw you over.

Best of Luck !

I should've read this forum before I bought my battery from sun-

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