48v 20ah Mr. Lau Chan / Lifepo4.hk pack arrived (May '09)

Hi needWheels
Well i didn't pay him yet so i guess i will see tomorrow or later tonight what his answer was. I was about to pay 705$ so he has some pretty good motivation to help me out although i could end up with some bad feedback if i don't pay for something! I can handle one bad feedback if i have to although it's not a resort i have taken before. When we started looking into the upgrade they offered me a good deal, this is what he had offered so i guess you can see the reductions and how fair they were, (when they proposed a 40Ah pack made from prismatics which i explained was going to be too heavy for an e-bike, next solution/propasition coming v-soon, we will see)
Here is the main part of the other email:

"Your motor is 2000W
48V30A battery can work , but not so suit , it probaby dies soon if working on 2000W motor

I think, if you use 48V40A battery, it will be better.

On the base of the original 705 USD for 18650 48V30A pack
I would like to give new price for the prismatic cell:

upgrade to 48V40A, add 150 USD (original 200 USD)
upgrade to 2000W BMS, add 100 USD ( original 150 USD)
upgrade to 6A charger, add 55 USD (original 98 USD)

If you wanna ship it by sea mail (6-9 weeks to arrive), subtract 100 USD from the total amount."

Generally i see that they are very helpful so far. I will know more tomorrow, i am aiming for a 20Ah with either high rate prismatics or cylindrical cells, i have offered to build the pack myself to save time and money. Lets see what happens, i will compare with headway to see. Thanks again, more soon.
Jimbo (James)
 
Oh if you have not paid yet, just stop there, seriously.
I can't get more insistent than that without sounding crazy, lol.

Remember sellers can no longer leave negative feedback for buyers on ebay.
All he could do is claim you as a non-paying buyer with ebay,
and that doesn't get you in trouble unless you do it a few times.

His prismatic packs @ 40ah would be over 31 kg (69 pounds)
Can you really carry that much on your bike? That's a crazy amount of weight.
Charging a depleted 40ah pack @ 6ah would take several hours too.

Get the 20ah headway instead, much lighter and can be charged faster safely.
If you need more than 30 miles range maybe get it built custom with 16 x 3 cells for 30ah
 
Today I tried to find max range. I say "tried" because I gave up! :shock:
It never cut out, not once, not even on some hills I threw at it in the middle and end.

I went 29.5 miles, I have to admit it was impressive.
I ran out of road and my butt was getting sore (no shocks, should have waited until my gel seat cover arrives tomorrow)

I moved the BD36 controller to where the heatsink fins are pointing right in the wind so that must have helped because this time it did not cut out at the same point where it did last time after rolling hills.

Final voltage was 50.2v which means in theory since the BMS cuts off at 46v (supposedly) there were probably another 5 miles left in there - though I've read that after 50v it starts to drop like a rock on the 18650's

The first 20 miles were not fast at all because I didn't have a dedicated bicycle lane, even some sidewalk riding. But I barely pedaled on purpose, only for hills and when starting from lights. I also stopped at a series of stores for an hour at the 13 mile mark.

The last 8 miles were flat out max speed possible with only a 10 minute stop at a store halfway through. Top speed was down at that point, from 28 to "only" 26 and it was more sluggish to accelerate.

Average speed of the first 20 miles or so was only 15mph
Because of the flat out non-stop of the last 8 miles the overall average rose to 16.4

Motor use time was 1 hour 45 minutes. Total trip time was 3.5 hours because of my stops.
Maximum speed was 31.8mph (downhill)

Temperature at the start of the day (7am) was 75 degrees or so,
last few miles were done in almost 90 degree heat, very sunny day.

Highest temperature in the pack after I got back was 103.8 F

Darn I should have measured the breakout voltage of the cell groups before I started charging but I forgot.

Maybe this really is using 1.6ah cells. Or maybe it's only because it's just a month old.
I know the hot temperatures help. I suspect the fact I went 20mph or less for the first 20 helped alot.
 
that's pretty good range and still you may get another 5 miles. You should be happy, for once, with Mr Lau Chan's product!
It seems that all of your cells are ok. No runt cells.
I've only gone 15 miles on my 48/15 pack. I stopped as there was no purpose to continue riding. Also, I have a fast charger (maybe 5 or 6amp).
Warning: sidewalks, in my experience, are more likely to produce flat tires. I got one Friday on my BD-36. luckily it was the rear tire. I shifted my weight to the front hub for about 1 mile. older tires are more prone to flats, also.
 
Unfortunately we don't really know if there are any runt cells as it takes a little longer for them to show up based on the old "JimmyWu" thread (and check out the exploded/vented cell in the cammycc thread)

Also I really wish I measured the balance when it was down to 50.2v, because that would have given some insight.

But this is only a month of use. At the end of the summer I'll try to do a similar range test to see if it gets worse.
In fact I might try to reach a town 25 miles away and maybe sneak a charge there while I rest.

I'm more impressed with the full speed 8 miles at the end than anything else, even if it was "just" 26mph because I bet it was reaching for more than 1C at that point, brushed motor and controller must have very been hot by then and the capacity of each cell was reduced from the previous 21 miles. I kept waiting for it to cut out and it just never did.

Oh and I discovered today how the BD36 deals with ultra steep climbs as reported by others. It's a very strange sensation. But amazingly it never cut out on that either (that was less than 10 miles into the ride).

It's been charging now at full blast for 3 hours, I suspect I have several more hours left @ only 2.5 amps.
I'd love a 5-6amp charger but Lau says I can't have that one, even though it's what they gave me the first time around.

ps. I absolutely swear by self sealing tubes. Just don't get the real slime brand because they spray green everywhere if there is a hole which is stupid. That flat tire I discovered over the weekend? Well it sealed itself and I rode it the whole 30 miles @ 60 psi with no problems. Bell Self Sealing Tube for $6.50 @ Walmart, only way to fly!
 
I agree that self sealing tubes are needed. I've been running on the plain ones that came w/ bike. The reason I didn't switch yet is that these Kendra Tires were supposedly puncture resistant.
The culprit was a sharp little thorn. With your kind of inner tube, the tire can be run down till it's bald without worrying much about flats. A friend told me that those types of inner tubes make for a firmer/sturdier tire.
Anyways,needwheels, your recent post is the most hopeful I've heard from you since early May. Maybe your only problem is the charger. With a good charger to top off pack, maybe you'll get even more range. a mile or so.
 
From what I have read and seen in photos the 18650 3A charger that all the vendors are using is the same as the SLA charger I have now, almost exactly. Even the same case, and it takes it up to 55v. I'll know soon though as the replacement charger left Hong Kong finally yesterday. So about 10 more days.

I didn't know Kendra made a puncture proof tire (I was actually looking at their 1.95 XC slick the other day but decided to stick with my 1.5 for now as I am beyond broke)

Instead of replacement tires I ordered the "flat stop 2" for $8 off amazon (covers 2 tires)
I am hoping I can get away with the smaller size since I only have 1.5 and not need the more expensive $12 one which covers up to 2.0 wide

But I definitely swear by self-sealing tubes, especially for the difficult rear tire.
It's 6 ounces of extra weight but will get you home every time as long as you have a mini-pump around.
 
Kenda does make puncture resistant tires. They are not puncture proof, "however". With time the tire becomes softer on the outside and thus more prone to puncture. This rear tire/tube went 2300 miles with no problems.
 
I've been worrying and reading about why the batteries get so hot (104 F) and apparently it's a sign of it going over 1C

The BD36 has been mentioned to use right around 20amps @ 48v at full throttle on level ground, so it should not be going over 1C ?

I'm still not convinced this pack is true 20ah, I think my distance achievement is from the 20mph or less for the first 13 miles or so.
 
Unfortuantely I have no idea and no way of testing that.
I only have one of those cheap $2 harbor freight multimeters.
 
THE WIRING FOR THE BMS CC AND LAU ARE USING, SHARED POSITIVE AND 2 NEGATIVE CONNECTIONS ONE IS ACCROS FRO THE POSITIVE AND THE OTHER IS IN THE MIDDLE OF THE BOARD ON THE POSITIVE SIDE. ONLY 2 WIRES FROM THE BATTERY. AS I SAID BEFORE I HAVE TWO OF HIS PACKS AND BOTH TEST ABOVE RATING 36V 20 AH IS 21 ? AH AT 6 AMP DRAW AND THE 48V 16AH IS 16.3AH AT ALSO 6 AMPS CONSTANT. THIS WAS TEST WITH MY CA AND A RESISTOR LOAD BANK. I ALSO SAID I GOT 60 MILES OUT OF THE 48V PACK AND THAT WAS BEFORE I TESTED IT IT;S ON MY S-60 SCHWINN 26", AND YEAH IT'S HEAVY. I RIDE MOSTLY BIKE TRAILS AND ROADS NOP OFF ROADING OR MOUNTAIN CLIMBING. YOU GUYS CAN LAUGH ALL YOU WANT ABOUT THE MILES BUT I DO PEDAL AS WE ALL ARE SUPPOSE TO DO, LIKE UNDER THE RADAR YOU KNOW. I WOULD SAY 15 OF THE 60 WERE UNASSISTED BUT THEN THERE WAS THE 30 PLUS RUNS DOWN THE ROADS. I FORGOT IT'S A 9C REAR HUIB FROM JASON, YOU KNOW THE CHEAP $180 JUNK, BOY I WISH I BOUGHT ANOTHER PIECE OF JUNK LIKE THAT ONE AT THAT PRICE. I ALSO REMEMBER THE LEGAL SPEED LIMIT IS 20 MPH SO YEAH MOST OF THE LONG RANGE WAS UNDER THAT LIMIT.
I JUST DON'T UNDERSTAND WHY WE ALL QUESTION / BITCH WHAT WE BOUGHT AFTER WE GET IT BEFORE WE GIVE IT A GOOD TEST, THEN WE CAN BAD MOUTH IT ALL WE WANT. AS FOR THE PACKAGING AND HOW THEY COME TO US, JUST THINK HOW BEAT UP YOU WOULD BE TRAVELING THOUSNDS OF MILES AND THROWN AROUND.
BACK TO MR. LAU BATTERY JUST RUN IT AND GIVE IT A CHANCE, I DID AND I AM HAPPY, BOTH PACKS ARE THE FOIL POUCHES NOT THE ROUND CELLS. I ALSO HAVE A PING PACK 48V 12AH AND IT DIDN'T KAST 6 MONTHS BEFORE IT LOST RUN TIME, WAITING FOR A FEW CELLS FROM PING AND IT WILL BE BACK UP AND RUNNING.
I WISH I KNEW HOW TO POST PICS IT WOULD HELP.
THANKS FOR LISTENING TO MY RAMBLIN.
DAND214
 
Thanks for the feedback on your experiences DAND214 (did you mean to use all caps?)

The pouch cells you are talking about are from a different factory and completely different creatures than the 18650 in my pack. You can't compare one to the other. In fact I am positive my 18650 pack is inferior to your pouch pack.

So your experiences of them being above capacity is meaningless to mine, in fact Lau has stopped selling 18650 packs entirely, claiming they suffer failures and short life which is what makes it even more alarming to me.

Given my experience with just getting the charger replaced, just imagine if there was a BMS or pack failure, I'd likely be completely on my own.

Your 48v 16ah must have been like this one of his here:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110385228116
and someone got a fantastic price on that too. I can only wish I had gotten that one.
 

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Oh is everyone ready for twilight-zone material here?
This is really getting weird - latest email from him:

I have checked with our technician this morning

The battery we send you was built with ping cells, not round 18650 cells
Click to expand...

Here is a photo of what he now says is inside this pack:
lau-foil-pouch-resize.jpg

They are labeled 7669130L which is something he used to sell under the ebay username mp3hk
http://google.com/search?q=7669130L

In fact I think that's what got that mp3hk account closed because he actually called them "Ping" which upset pingping227 and got ebay to shut him down.

Since the records are long gone on those ebay listings, here is what I dug up:
Dimensions (H x W x L) 6.9mm x 76.5mm x 133.0 mm
Weight: 128 grams
Max. Charging current, 4 A
Max. Discharging current, 8 A Max. ( continuous); 16 A Max ( 18 second pulse)

a 20ah pack would have 80 of them 16s5p

weight would be 128 * 80 grams = 22.58 pounds
width would be 76.5 * 2 millimeters = 6.02 inches
length would be 40 * 6.9 millimeters = 10.87 inches
height would be 133.0 millimeters = 5.24 inches


How can I prove this once and for all without completely cutting open the battery?
If only I had a charger that went to 60v I could tell by the voltage hot off the charger.

update: if his claim is true, apparently these are the cells he used to try to sell individually:
http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=7617
 
Replacement charger just arrived.
It was just put into a manila envelope with a 2mm thin layer of foam.
Fortunately it seems to work, I guess. Output voltage without any load is 59.5 volts.
It seems to be brand new. The insides look very cheap and the heatsinks are tiny.
(the heatsinks are very scratched and the bottom of the board is actually dirty?)

The board shows SBT-81119G and there are two part numbers in the corner SN-71119A SN-81119A
The main transformer is labeled KH-00830002 BT-483-81119

I put it on my pack which was previously charged up by my 55v SLA charger and after 30 seconds it went to green and stopped. Now it cycles in a burst every other minute.

(is it safe to run my voltage meter in parallel to watch what it is doing?)

Photos in a few minutes.
 

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I put my voltage meter in parallel to snoop on what the charger is doing to the pack
and it appears to be fluctuating between 59.7 and 59.8 volts.

Is it safe to charge 18650 cells at that high of a voltage? (near 60v)
 
Should be. What you are seeing is the bms balancing the pack, which only happens when it gets to the higher voltage from the new charger.

Now you should be able to go out and get riding, and see how it turns out. I have heard of people that are very happy with thier lau chan 18650 cell packs so you may get lucky and have a good one. The problem isn't so much the cells themselves, as the lack of testing them before they build a pack in my opinion. Just ride what you have, keep the amps reasonable, and avoid 100% discharges and you may get plenty of use out of the thing, even if it never proves out to have the advertised capacity. Enjoy the bird in the hand while you can.
 
If it really is balancing now, something is strange because the voltage is not going above 54.1 volts anymore.

Even on my old SLA charger for a few hours (which has 55v output) the pack voltage has not gone beyond 54.1 volts

What's interesting is the 59.5 volt charger does NOT take out my HDTV signal like the 55v one does, which is nice, that is IF it's doing anything.

Weird. I am going to give a 8 mile run at full speed tomorrow and see what the 59.5 volt charger does.

I am also going to make plans to carefully open one corner this weekend and see what's really inside.

If it really is foil, I better be darn careful not to puncture a pack.
 
After several hours on the new 59.5 volt charger I took it off and it's still 54.2 v

I then immediately tested the BMS breakout points and I see a real problem growing here, and probably why it's stopped. note the 3.8 volts.

3.36
3.35
3.36
3.36
3.35
3.32
3.8
3.5
3.3
3.4
3.3
3.4
3.3
3.4
3.4
3.3


here are the actual voltages as tested, note the 20.1 to 23.9 gap which is the 3.8 volts:
3.36
6.71
10.07
13.43
16.78
20.1
23.9
27.4
30.7
34.1
37.4
40.8
44.1
47.5
50.9
54.2
 
Took the bike for a purposely rough 8 miles this morning to try to make the BMS discharge the battery evenly.

Apparently it worked, when I got back it was almost exactly 3.30 across all the points.

The good news is that the 59v charger works and it charged the pack for 2.5 hours after that but the bad news is it stopped at 54.5 volts / 16 = 3.40 volts per group

Since the foil pouches supposedly stop at 3.66 volts per group, I am virtually positive this is not foil pouches like Lau is now claiming.

However I am planning to carefully cut open a corner on Sunday to see once and for all what's in there.
 
Yup, I understand that. But other people, I think even in this thread, that have Lau foil pouches get 3.66 volts hot off the charger.

The last email from Lau was a few minutes ago and he insists this is a foil pouch pack (he calls them "Ping cells" lol)

He wants me to open it and take photos, which is what I was planning to do anyway this Sunday.

It's been on the 59.5 volt charger for 5 hours now and it's still 54.5 volts, so unless that 3.66 is wrong, this isn't prismatic.

I also want to find an accurate scale to check before I open it.
Trying to figure out where to get one, I didn't see one at walmart today.
Needs 25 pound support which would be a postal scale but I can't afford a $100 scale, even if I buy/return it.

I told Lau if this really is a foil pouch pack, I'll cancel my dispute with him and apologize.
I wouldn't mind being wrong, I really wouldn't.

update: here's someone with the exact same cells Lau is claiming I have and they get 3.66v final
http://endless-sphere.com/forums/viewtopic.php?f=14&t=9388#p155014

here's another person with Ping v1 who gets 3.66v final:
http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=2931&start=645#p52352

(searching for more...)
 
Balance after nearly 9 hours on the new charger:

3.36
3.36
3.36
3.36
3.5
3.36
3.7
3.5
3.4
3.3
3.4
3.3
3.4
3.3
3.4
3.3

That one group keeps going over voltage while the others stay down. Third time I have observed that.

Actually, now the 5th group is showing 3.5 too.

Sigh, I dunno what to do, I'm pretty much stuck with this beast.

I guess I will let it trickle all night and hope this piece of junk charger doesn't burn the apartment down.

If I open it on sunday and it's foil pouch, does that mean the BMS is not working right as far as getting it to 3.66 like the other foil pouch packs made of the same cells?
 
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