Ypedal said:
https://www.youtube.com/watch?v=kBMnHYaymHU
Random find.
[youtube]kBMnHYaymHU[/youtube]
Thank's for posting my video here for discussion.
I had come across this post in search for some more information. So I thought, I might as well register and give you some of my opinions.
First of all the pack still works great. When I use the tandem-bike all alone, it will take me about 90-100 km. When I paddle hard and use an
old pack for the second engine, for things like accelerating from 0-25km/h or up hills, I will go about 110 km.
With two people on the bike, and my wife is lazy putting her feet up, it's about 75 to 85 km depending??
After about 50 to 60 full charge cycles, I opened the pack and found it slightly off balance. The pack seems to turn off once any of the cells exceeds 4.22 V.
So, when it only charges to 28.9 V instead to 29.2 V I need to open it and re-balance it manually which takes a Sunday afternoon.
riba2233 said:
Not really. This method is ridiculous.. And just to think that he believed that those "4600mah" cells were real :lol:
First of all 18650 cells are a new standard. Not really new, though. The thing that I find ridiculous is the fact that I have to build this myself.
The pack companies should have done this a long time ago already.
Did I believe that those cells had 4600mah? Not really, otherwise I had not used 84 cells, instead only half of that.
I thought they might be cheating a bit and if it's only 60% of that, I got some cheap solution. Of course, there was that hope. This is Taiwan! Maybe some BYD connection spilling onto the island.
However, as it turned out, it wasn't even 30% of what the claims were.
chilledoutuk said:
What is this obsession with making battery packs using 18650 cells without soldering or welding? it makes no sense to me.
I mean in the time it takes you to make one of those packs i could have soldered up about 5 packs or more and my construction is more compact and permanent.
If any of your cells start loosing capacity or cant hold the charge, the whole pack goes down.
There is no way to isolate the problem easily.
Soldering has it's very unique dangers also, especially when soldering on the positive pole. The negative and the positive are only mm apart.
This can easily be bridged while or after soldering if anything was done incorrectly.
Most packs last for about 3 years and need to be replaced. If you can check all the cells in less than 10 minutes, you can continuously take out the bad ones and
replace them, thus keeping everything at optimum performance and possibly extending the life of the other cells. You'll actually never buy a pack again.
riba2233 said:
Great pressure is not needed, so it wont impact cells.
It is faster, but you have to have a good way of doing it. Unfortunately there isn't a superior way to do it yet, but I'm working on and will soon have ready the great design for joining cells solder less and weld less.
Of course there is a better way of doing it. One is even in my video's description.
I should have made the top cell holder that holds the 84 cells in place a few millimeters thinner and instead of the redundant two double layer top connectors, I should have/will make 7 separate tops similar to the ones shown in the video.
Those seven tops should hold the copper plates including the nipples and connect to the board. They each should then have 6 screws pulling the top down onto the big Plexiglas holder.
This would let me get rid of that extra strong and rigid lid.
The next pack I build will not let the power run through the spring on which each cell rests. Instead, the spring will be shielded and have a connection plate/nipple on top. From there I'll run a copper cable down onto the copper plate. That cable would thin out to the top end where it serves as a simple fuse.
Any more suggestions?
Thanks!
