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

needwheel, I just bought a 48/20 pack f/ icecube on endless sale sight . got it at a pretty good price. it's ligtly used and has a few runt cells. but this pack will allow me to put 48v lifepo4 on my bd36 without have to spend alot. pack is only good for 16.5 ah, though.
My other pack will only work on my Aotema brushless.
I can soon compare my BD36 speed to yours' as we will have both have 48/20 18650 packs.
 
I wouldn't have knowingly bought a 18650 pack but hopefully you paid a good price.
It looks like a cammycc pack with the better bms and 16s18p layout.
As long as that BMS gets some airflow it will easily allow 2C continuous (I have the same BMS).

The problem is if you get one runt in there, you have to cut open the whole thing and repair it, so hopefully you know how to do that and how to solder onto lifepo4 cells carefully.

Look at the cammycc repair thread by ypedal for more insight.
I believe 18650 packs start hot off the charger at 54-55 volts.

I currently get 28mph peak on the bd36 on what has turned out to be the equal of a Ping V2 pack clone.
But the 28mph doesn't come easily or instantly, takes a half mile of buildup, and I've never, ever, seen 29mph on level ground (except with heavy tailwind or the "side" wind incident next to heavy traffic)

26mph is far more common, I see that all the time, and actually that's fine as it feels a little safer than 30.
 
icecube says that this pack is 60 v hot off the charger. It settles down to 55v after a mile riding or several hours sitting.
I have a soldering iron but have little soldering experience. Also, this pack has 288 cells 1.1 or 1.2 ah cells.
I'll just try not to drop it. Finding a runt or dead cell seems like a nightmare. I have view the Cammy CC "surgery"
pics.
This pack presently doesn't quite need opening as it is good for 16.5 ah. If I tried to find the problem cells, I could mess up the whole pack. Why get greedy for another 3.5 ah?
If the pack wasn't broken-in correctly, the runt cells can possibly be revived by riding 1 mile and then recharging. Repeat this 5 or 10 times.
First and foremost I'll heavily protect this pack and try not to drop it.
This volgood pack makes my BD-36 a better "for sale" item, too. Though that's not my plan yet.
 
Correction: the volgood 48/20 pack settles down to 54 or 53 v when resting. 55 v is inaccurate.
 
that's normal. i don't think there is much wrong with it except it is smaller than advertized by cammycc or vpower or whoever it is now. if you can measure the voltages on each of the sense wires then you may find one row a little lower than the others. if you had a dead cell in one of the rows, it would just pull all the others down with it which are in parallel on that row and you would see it. so i think it is ok as it is, check them if you can reach them. and keep it charged.
 
dnmun, I just bought this pack f/ icecube57. He was unhappy with it because it only delivers 16.5 ah. Ebayer volgood says BMS cuts it out at that point to preserve pack.
I bought it at a good price fully aware of a possible few runt cell. Fed Ex shipping still has it. My guess is that it will give me 20 miles range or more
 
I have test ridden the 48v 20 ah volgood pack. Without wind or pedaling, I go a top speed of 29 mph w/ my WE BD36.
This 3 amp charger goes up to 61 or 62 v. It is tweeked higher. It gives 60 v on this pack and about 62 on my olympics pack.
The volgood pack seems to charge slower than the olympics pack, which leads me to further suspect that olympics packs are made of A123's. I can't be sure though as a 3 amp hr charger should do 3 amps charging regardless of lithium type.
 
I can say for sure that icecube57 gave me a good deal on a "used" Volgood pack. He put about 50 to 75 cycles on it. The only problems so far are 1) a smoking/broken charger (I dropped it ) and 2) BMS cut-outs.
The BMS cut-out has been fixed or reduced.
The only obvious negative is that this 48 v 20 ah pack goes around 28lbs. It weighs nearly as much as 36/12 SLA.
 
I won the first auction of Mr. Chan's where he had switched to prismatic cells (before I found this forum) and was nervous when his account was suspended on Ebay. The reviews here made me even more nervous but just crossed my fingers and hoped for the best. I received the battery (48V20AH 16s pack), and have to admit I got it for a song. Had only taken it for one test ride and knew that I was going to have to split the pack to make it feasible. Originally decided it would have been nice if I had asked him to do it for me, but am now very glad I am doing it. Took awhile to get through the duct tape etc and was packed nicely (hope the batteries are as good of quality as the duct tape). While looking at the top I noticed that one of the connection nuts didn't appear to actually be tightened down....four of them were loose. Ouch! Moral of the story, open your package and check your nuts. :roll:

 
My top speed is down to 26mph now, I don't know what is going on. I rarely see 27 and never 28.

It might be that I switched to new tubes recently and I also put in stop-flats liners, might be increasing rolling resistance.

I think I am going to switch tires soon though, I decided to leave last morning on a rare pre-dawn ride to the store and a car coming out of a side-street decided they didn't need their lights on in the barely rising sun for some reason. The good news is my brakes worked incredibly well as I stopped from 20+ mph in less than 20 feet. I recently changed the pads, but the tires only being 1.5" had barely any road contact to stop on so it was a scary skid the whole way. Disc brakes would not have helped, wheels were in a completely lock at the time.

Hot off the charger is only 55.6v still, I never see the 57+ that others get unless I leave it balancing for many, many hours.

I think paypal killed Lau's account, not just ebay.
I didn't push the issue with paypal and let it close but I wasn't going to defend him either.
He needs to stick to small-ticket items and not risk being unable to replace items in a timely/cost-effective manner.

I just hope this pack lasts a few years or all this headache wasn't worth it.
 
Maybe you should check your motor brushes to make sure you are getting proper contact. I just replaced my BD36 brushes with new ones after 2300 miles because of a contact problem. Greater friction at 48 v could have caused this?
They had about 1/2 inch left, but one of the brush springs was jamming and it eventually left me without power. Another thing you can check is the thumb throttle. Make sure the gear shifter or brake holder are not hindering full use of throttle.
Beyond that, it's hard to say what your top speed problem is. I doubt higher air pressure and new slick tires will give you
more than half a MPH.
My BD36 will do around 28 or 29 mph (no wind) whether it's at 58 volts + or 52 volts. I'm referring to my 48/20 volgood pack. This pack rests at around maybe 56.8 v That's a pack sitting for more than a day. An average of 3.55 v(3.55 x 16).
I have noticed that this 18650 pack will charge to green light, then the red light will occasionally come back on for 5 seconds. This is unlike my other lifepo4 pack.
I recently switched to self sealing tubes and this seems to have no bearing on speed. I weigh 170#. If you weigh 200# +, this could mean 1 or 2 mph slower. Also, consider that a hot BD36 hub will likely run slower than a cold hub.
There are a few riders who say that the BD36 comes in different versions/models such that some will do close to 26mph
and others will only do 22 or 23(with the same weight and conditions).
 
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