Ok, I bought a (slightly) used duct tape (Vpower) battery...

[OCD]

I was looking at the $530 (shipping included) V-power (style) 20a 48v http://www.ebay.com/itm/48v-20ah-Li...ltDomain_0&hash=item1c1f55a385#ht_3665wt_1270 which is aprox $270 cheaper (shipped) than the ones produced by Ping http://www.ebay.com/itm/48V-20AH-Li...ltDomain_0&hash=item3366f567fc#ht_2146wt_1037. What I hear most everyone saying is I'd be better to buy a Ping 15a 48v http://www.ebay.com/itm/48V-15AH-Li...s=63&clkid=3150168728389482682#ht_1567wt_1037 which is only about $100 more than the V-power as it would have roughly the same capacity as an over-rated V-power pack anyway? Could I expect the packs from Ping to have a greater life expectancy/lower cell failure rate too? There must be a reason for such a spread in price. :?

 

[sangesf]

Actually, you're better off going with a YXM duct tape battery...
The 36v "20ah" one is actually 21AH!!!
For $389 SHIPPED, you get an awesome battery!!
That's why when I saw the 36v "20ah" battery on eBay for $250, I snatched it up.

For what I paid, I really can't complain since they gave me back $50...

This pack consistantly is giving me 15ah, so I'll just deal with it..
In this case, I got what I paid for.

I still think it's really only a 15ah battery, (Dimensions and weight indicate 15ah) that's actually working properly, because the seller REFUSES to show me a receipt or invoice...

If I ever need to, once I open the pack. I'll be able to see how many parallel connections there are..

 

[OCD]

I've compared the various 48v 20a packs which include BMS/charger on eBay and have noticed from Sun_Thing it weights 8.6kg, from YXM 9.5kg, from Vpower 12.5-14.4kg (in the same advert) and Ping is 9.5-9.9kg. Should I assume if it's heavier it's more likely to be closer to the rated output?

Thanks

 

[sangesf]

I've compared the various 48v 20a packs which include BMS/charger on eBay and have noticed from Sun_Thing it weights 8.6kg, from YXM 9.5kg, from Vpower 12.5-14.4kg (in the same advert) and Ping is 9.5-9.9kg. Should I assume if it's heavier it's more likely to be closer to the rated output?

Thanks

SunKing, I have no knowledge of.. YXM uses (From what I could tell and what they told me) use 26650 3.0ah cells so they actually give you a 16s8p setup which is really 21ah! (I had their 36v "20ah" battery which CONSISTANTLY gave me 21 ah..), Vpower uses 1-1.1ah cylindrical cells which apparently way more then other counterparts, and ping (I believe) uses prismatic (pouch) cells of 2.5ah each (which weighs less then cylindrical)...

I personally had great use out of my YXM pack (before it got stolen), and everyone agrees Ping has the best packaging and customer service out there. (Albeit, for a price).

It depends on if you want to take a chance on YXM or spend $270 more on ping..

That's my .02

 

[amberwolf]

I've compared the various 48v 20a packs
<snip>
Vpower 12.5-14.4kg (in the same advert)

Not counting the charger, both the Vpower pack I have and the Volgood pack here for repair, each 48V "20Ah" spec'd, weigh just about 25lbs, including the BMS (which itself is probably a pound).


Keep in mind that with the pouch batteries like Ping, there arent' really any construction issues that will come back to bite you later. Well, other than it getting dented or banged around, crushing corners or edges of cells, or getting holes poked in them from sharp stuff, but the same can happen to any other duct-tape pack.

With cylindrical-cell batteries like Vpower, Volgood, CammyCC, etc., it's a fair bet that at some point some of the tab/strip welds to the cells are going to break, and cells will become poorly connected, or disconnected entirely, causing assorted types of pack problems, from reduced capacity to outright pack failure, requiring quite a bit of disassembly of the pack to fix.

 

[jmack]

I purchased one of those 36V 20AH YXM Batteries and they are absolute crap just like those V Power ones same problem..
I have 7 cell groups at 3.33V and refuse to charge any higher and 5 cell groups that are ok at 3.65..
Once you catch them out they won't reply to emails either.."Once caught twice shy"..
I will never purchase a cheap Ebay battery again..Its a quick way of wasting money..I have learned my lesson

I have gone Lipo now.. Just built 2 10S 3P packs and now have the E Bike grin..
Regards John

buy the way Sellers name is DAOJI888 on eBay and YXM are one in the same!!

John.

 

[jmack]

I've compared the various 48v 20a packs which include BMS/charger on eBay and have noticed from Sun_Thing it weights 8.6kg, from YXM 9.5kg, from Vpower 12.5-14.4kg (in the same advert) and Ping is 9.5-9.9kg. Should I assume if it's heavier it's more likely to be closer to the rated output?

Thanks

SunKing, I have no knowledge of.. YXM uses (From what I could tell and what they told me) use 26650 3.0ah cells so they actually give you a 16s8p setup which is really 21ah! (I had their 36v "20ah" battery which CONSISTANTLY gave me 21 ah..), Vpower uses 1-1.1ah cylindrical cells which apparently way more then other counterparts, and ping (I believe) uses prismatic (pouch) cells of 2.5ah each (which weighs less then cylindrical)...

I personally had great use out of my YXM pack (before it got stolen), and everyone agrees Ping has the best packaging and customer service out there. (Albeit, for a price).

It depends on if you want to take a chance on YXM or spend $270 more on ping..

That's my .02

The DAOJI888 aka YXM on eBay. 36V 20AH is 12s 7P not 16s8p..3x7=21 and 3x12=36 And CONSISTANTLY gave me less than 15AH

John..

 

[sangesf]

Up until THIS particular battery, I must have been one LUCKY SON OF A BlTCH!?!?

All of my batts except this one (and my first ever bought 24v 30ah from that one guy who kept changing his ID every month or so) have worked to spec...

Maybe, only the people who have complaints have spoken up?
And for the one poster who said his cell groups never went above 3.3x volts, maybe try a single cell lifepo4 charger to bring them up to 3.65...
THEN the pack should stay balanced and you'll probably get 15ah...
And yeah, I meant 12s7p.. Oops.

 

[sangesf]

I purchased one of those 36V 20AH YXM Batteries and they are absolute crap just like those V Power ones same problem..
I have 7 cell groups at 3.33V and refuse to charge any higher and 5 cell groups that are ok at 3.65..
Once you catch them out they won't reply to emails either.."Once caught twice shy"..
I will never purchase a cheap Ebay battery again..Its a quick way of wasting money..I have learned my lesson

I have gone Lipo now.. Just built 2 10S 3P packs and now have the E Bike grin..
Regards John

buy the way Sellers name is DAOJI888 on eBay and YXM are one in the same!!

John.

I'll buy it off you, since you think it's crap...

 

[jmack]

Up until THIS particular battery, I must have been one LUCKY SON OF A BlTCH!?!?

All of my batts except this one (and my first ever bought 24v 30ah from that one guy who kept changing his ID every month or so) have worked to spec...

Maybe, only the people who have complaints have spoken up?
And for the one poster who said his cell groups never went above 3.3x volts, maybe try a single cell lifepo4 charger to bring them up to 3.65...
THEN the pack should stay balanced and you'll probably get 15ah...
And yeah, I meant 12s7p.. Oops.

I have spent the last 3 days trying to charge the lower cell groups with a single cell charge and they keep dropping back to 3.3 to 3.4..
They won't hold the charge!!!7 cell groups STUFFED 5 cell groups ok pretty dam slack less than 50% any good..
I also ordered and payed for a new BMS and 5amp charger 12 weeks ago still waiting..
Not a good ebay seller DAOJI888 aka YXM on eBay. to deal with as far as I am concerned..They won't reply to emails either..
Very SHONKY and bad business ethics.. I will use it on my wifes trike till it dies completely ...

John.

 

[sangesf]

Make sure the charger is putting out at least 45.x volts.
If it is, leave it plugged into the battery for an entire week...
Bet you a billion dollars (if the BMS is working properly), that the cells will all end up at 3.6x+V.
It's funny, every time I ask to buy a "crap" battery from someone they ALWAYS say, "I just use it for (make up any reason you want) until it dies..."

Let me ask you, what's the capacity it's at now? Is it a BMS that's the 17a one?
Have you tries leaving the charger connected for any length of time? If you watch the charger after it's gone green, I bet you it goes red again after about 10 min (for about a min) and repeats that process.
(That's the BMS balancing the cells.. When it's done with balancing the charger will no longer go green-red-green)
If it's "crap" let me buy it and use the money to buy your wife a "non-crappy" battery.

 

[jmack]

Make sure the charger is putting out at least 45.x volts.
If it is, leave it plugged into the battery for an entire week...
Bet you a billion dollars (if the BMS is working properly), that the cells will all end up at 3.6x+V.
It's funny, every time I ask to buy a "crap" battery from someone they ALWAYS say, "I just use it for (make up any reason you want) until it dies..."

Let me ask you, what's the capacity it's at now? Is it a BMS that's the 17a one?
Have you tries leaving the charger connected for any length of time? If you watch the charger after it's gone green, I bet you it goes red again after about 10 min (for about a min) and repeats that process.
(That's the BMS balancing the cells.. When it's done with balancing the charger will no longer go green-red-green)
If it's "crap" let me buy it and use the money to buy your wife a "non-crappy" battery.

Been there done that.. I have left it on for 5 days straight and left it on charge overnight several times those crook cells still drop back to 3.3v...
I would be careful about silly betts if I were you... And the charger is putting out 45v..
cell 1...3.34
" " 2...3.33
" " 3...3.33
" " 4...3.34
" " 5...3.56
" " 6...3.62
" " 7...3.42
" " 8...3.33
" " 9...3.63
" " 10...3.33
" " 11...3.34
" " 12...3.53
And that is off the charger after 24hrs...41.1v that will drop when I let it sit for awhile to about 40.2 or less at times..
I have tried single cell charging with a Nokia cell Ph charger the lower cells go up to 3.45 on the charger for several hrs
still won't go ant higher..I have also discharged the higher cells down to 3.33 and recharged the whole pak same result..
Man I have tried everything and no success
So my conclusion it is a piece of "CRAP"
I doubt that you would buy this piece of Crap and pay for shipping from Australia to the US you could almost buy a good one for that cost..
Now when can I collect my Billion $ ha ha ha..lol...

Letts face its a lucky dip with these DAOJI888 aka YXM Ebay batteries..

John..

 

[Spacey]

A crappy cell like the one that is not behaving in this 48v 16Ah Headway pack I am fixing will take ages to balance. I have a Signalab BMS (not impressed to be honest the charging FET broke) which has LED's to show when the cells hit 3.65V.

The crappy cell takes about 12 hrs to hit 3.65v but goes out instantly when you take the charger off, I suspect this is the cell causing the 16Ah pack to cut out after 2Ah's.

 

[sangesf]

Make sure the charger is putting out at least 45.x volts.
If it is, leave it plugged into the battery for an entire week...
Bet you a billion dollars (if the BMS is working properly), that the cells will all end up at 3.6x+V.
It's funny, every time I ask to buy a "crap" battery from someone they ALWAYS say, "I just use it for (make up any reason you want) until it dies..."

Let me ask you, what's the capacity it's at now? Is it a BMS that's the 17a one?
Have you tries leaving the charger connected for any length of time? If you watch the charger after it's gone green, I bet you it goes red again after about 10 min (for about a min) and repeats that process.
(That's the BMS balancing the cells.. When it's done with balancing the charger will no longer go green-red-green)
If it's "crap" let me buy it and use the money to buy your wife a "non-crappy" battery.

Been there done that.. I have left it on for 5 days straight and left it on charge overnight several times those crook cells still drop back to 3.3v...
I would be careful about silly betts if I were you... And the charger is putting out 45v..
cell 1...3.34
" " 2...3.33
" " 3...3.33
" " 4...3.34
" " 5...3.56
" " 6...3.62
" " 7...3.42
" " 8...3.33
" " 9...3.63
" " 10...3.33
" " 11...3.34
" " 12...3.53
And that is off the charger after 24hrs...41.1v that will drop when I let it sit for awhile to about 40.2 or less at times..
I have tried single cell charging with a Nokia cell Ph charger the lower cells go up to 3.45 on the charger for several hrs
still won't go ant higher..I have also discharged the higher cells down to 3.33 and recharged the whole pak same result..
Man I have tried everything and no success
So my conclusion it is a piece of "CRAP"
I doubt that you would buy this piece of Crap and pay for shipping from Australia to the US you could almost buy a good one for that cost..
Now when can I collect my Billion $ ha ha ha..lol...

Letts face its a lucky dip with these DAOJI888 aka YXM Ebay batteries..

John..

Did you try to charge to 3.85 +\- .05v?
Then let them sit for an hour and charge again..

On a pack someone gave me (11s14p), I had to charge each cell group to 3.8 at 200mv and then wait an hour, recharge again to 3.8x, and over and over (a couple of weeks) until they settle back to 3.5x, then charge to 3.9x at 100mv until they settled down to 3.6x (another couple of days)....
The "15ah rated" pack started at ~ 10ah and after my little fight with it (over a month), I was able to now get almost 14ah out...

It still runs today at between 13-13.5 ah after 6 months on my son's ebike..

You still didn't tell me what it's nominal capacity is...
Another caveat is that you said they never get about 3.45.. No matter what, they should.. I would try a 6v 1a SLA charger on pairs of cells, they usually don't quit until the total is 7.4-7.6v (Just watch each group.. They HAVE to go above 3.45.. I've NEVER SEEN a cell (or group) not hit any voltage (given enough V/A) unless it's a dead cell...
Since you say they charge past 3.3x they are obviously not dead.

 

[jmack]

Hi sangesf..
The nominal voltage of the pak is purposed to be 38.40V the cells are 3.2V x 12=38.40V..
I will keep doing what you suggest and see what happens thanks for your help..

As you know we should not have to go through all this mucking around to try and fix
something that is supposed to be plug and play not plug and fix..
so what DAOJI888 aka YXM on Ebay sold me is Crap and he or she are shonky sellers..
anyway thanks again sangesf..
John..

 

[Jason27]

What is the lesson here? You get what you pay for. Reputation is everything. I would only buy from these battery sellers and no one else.

Cell man
hobby king lipo
allcell
ping

 

[sangesf]

Hi sangesf..
The nominal voltage of the pak is purposed to be 38.40V the cells are 3.2V x 12=38.40V..
I will keep doing what you suggest and see what happens thanks for your help..

As you know we should not have to go through all this mucking around to try and fix
something that is supposed to be plug and play not plug and fix..
so what DAOJI888 aka YXM on Ebay sold me is Crap and he or she are shonky sellers..
anyway thanks again sangesf..
John..

Most battery sellers will tell you 3.2v, 99% of my batts usually are 3.3v (or 39.6 for a 36v pack) for the majority of the cycle (95% to 30% DOD).
Even the 11s pack on my sons bike is 3.3 (36.3v) for the majority of the ride.
What's the capacity currently at.. In other words how many AHs are you currently getting out of the pack?

 

[sangesf]

What is the lesson here? You get what you pay for. Reputation is everything. I would only buy from these battery sellers and no one else.

Cell man
hobby king lipo
allcell
ping

Well, every Vpower and YXM Battery I ever bought from them directly, has worked to (and beyond) MY expectations / their specs..

All the ones you like have done well for you and others..
Cheap (Re: inexpensive) duct tape batteries have worked well for my needs..

Now this may be, because I use them at (or below) their rated specs...

In every one of the batts I've used, I've NEVER used more than 1C continuous or even 1.5C Max.
Some people will take a 36v 10-15AH duct tape battery and pull 20-25a (1.5-2.5C) continuous and wonder why the batteries don't last or hold up to their rated capacity... Well DUH!

 

[jmack]

This 36v 20ah Battery from DAOJI888 aka YXM on Ebay has never been any good from the day I took delivery..
I charged the battery from 2pm till 9am the next day..
The charger had stopped clicking to red and the green light was on
I installed it on my bike and when I connected the leads I noticed on my power Analliser
that the voltage was only 42.1V and that was the best it has ever been..
over the last 12 to 14 weeks I have tried single cell charging..and extended charging
and all the things you have recommended most I have done previously

This afternoon I removed the duct tape to check things out..
The cells are 3.2V 6WH That is what is printed on the cells..
there is 12cells in series and 7 in parallel
All connections that I can see look ok..

When I ride my bike I average about 16amp sometimes it dose hit 20Amps
for short times but not very often..
I think Jason is dead right in saying you only get what you pay for I have learnt my lesson..

I have put together 10s 3p lipo packs from HK for both my bikes..
1hr charged and balanced I couldn't be happier..

And will NEVER EVER BUY Cheap CRAP from DAOJI888 aka YXM on Ebay again..

Good luck sangesf..
John..

 

[sangesf]

What was the best AH capacity you have gotten?

 

[jmack]

I have only done 1 LVC test and that was just under 16AH..
Due to the state of this Battery its pointless in doing another
until I can improve its charging ability..
John..

 

[theRealFury]

This afternoon I removed the duct tape to check things out..
The cells are 3.2V 6WH That is what is printed on the cells..
there is 12cells in series and 7 in parallel
All connections that I can see look ok..

Well at 6WH per cell that would make them 1.9AH each but that cant be right as that would mean the entire 7 parallel string is only 13.3AH. at 16AH that would make each cell a 2.3AH cell or 7.3wh which is what you got on your LVC test. My guess is that they are supposed to be 3AH cells but obvously are not performing as such.

I have heard of DAOJI888 before, he has a reputation spanning a couple of years with dodgy batteries sorry to hear you got taken in by him

 

[jmack]

This afternoon I removed the duct tape to check things out..
The cells are 3.2V 6WH That is what is printed on the cells..
there is 12cells in series and 7 in parallel
All connections that I can see look ok..

Well at 6WH per cell that would make them 1.9AH each but that cant be right as that would mean the entire 7 parallel string is only 13.3AH. at 16AH that would make each cell a 2.3AH cell or 7.3wh which is what you got on your LVC test. My guess is that they are supposed to be 3AH cells but obvously are not performing as such.

I have heard of DAOJI888 before, he has a reputation spanning a couple of years with dodgy batteries sorry to hear you got taken in by him

Hi theRealFury
Correction I didn't have my reading glasses on this is exactly what is printed on the cells..
[BTJ-8.6wh-3.2v] I thought the 8 was a B sorry about the confusion..
Not to worry I will put it down to experience I might be able to salvage enough cells to build a 24V 15AH battery
for my wifes Trike..Anyway this shonky seller on ebay DAOJI888 aka YXM has probably done me a favor in a way..
I have now switched to Lipo.. I have 8yrs experience using Lipo with my RC hobbies so they are not new to me
probably should have gone that way in the first place..I just hope others don't get caught by them..

Cheers John.

 

[theRealFury]

Well im sure lipo will treat you better than those LiFePo4 in that case Even with the missread on the cell info those cells in that pack would never put out 20AH. at specification you would be looking at 18.5-19AH max. Its a shame there are people out there that will screw anyone over for a few $$.

 

[999zip999]

In some places it is a honorable thing to sell the bad fruit as you will not eat it. Or the crap you are selling. Cheap is cheap... Good luck in the future