Understood. Thank you!
Let’s wait for a couple days, I might have an option closer to me, just waiting for a confirmation. If this doesn’t work out, we can talk on Monday and I’ll take yours.
1 Like
Still having a bit of trouble taking out the old cells from the plastic case. They’re stuck in there with what looks like somewhat flexible white silicone glue.
Any tips here? Apart from just slowly pulling and wedging things in the sides to help?
U can use any lifepo4 cells with the bms as they are the same chemistry and all have the same voltages for full and empty.
2 Likes
I finally managed to remove the old cells glued to the bottom plastic case. They did not skimp on that while silicone glue, lol. A bit of IPA and brute force helped. Some of the cells lost their plastic shell but either way, I don’t think any of them are salvageable. Maybe really only 2-3 I saw were a little over 2v. Will probably use them for the spot welder calibration before building up the pack with the new cells.
Speaking of replacement cells, I ended up ordering from battery clearing house, one of the packs linked above. I heard good things about them from other sources too so I’m not too concerned. Only thing is that it’ll probably take some time for the package to get to me. The website kept switching their estimation between 5 and 9 business days.
In the mean time, I’ve done a bit more work on the rest of the board. Had to rebuild one of the rear wheels as a few bolts had broken off when I tried to take the drive gear off a few years ago. I ended up cutting down all the aluminum standoffs, drilled the holes a bit deeper and extended tapped threads. Then I drew up and 3d printed an ABS spacer. Seems to fit well and feels solid. We’ll see how it works.
They key words for this build is “use what we already have” 
If it’ll be as much fun to ride as I remember it used to be, we’ll swap all the gear and electronics eventually.
2 Likes
They’re here! They’re here!
On a quick look the pack seems fine, all cells I measured randomly read around 3.3v
Now for the fun part to take this apart without damaging them.
To be continued.
3 Likes
just mount the whole thing on and call it a day 
3 Likes
Slow progress. Getting there but taking the cells apart and cleaning the spot welds is pretty tedious.
2 Likes
nickel all ripping off cleanly?
Those packs might be ok but the long skinny ones the welds tore through the cell wall…
2 Likes
I’ve pulled at least 80 of those packs apart. At that point it was easiest to stick a wedge between them (plastic screwdriver) and leverage them apart. The goal being leverage against each other so left with the complete nickel strip connected to a single positive terminal which is then easy enough to then pull off with pliers. I remember this is the possibly big shorting stage.
3 Likes
Yes, I’m wedging the sections of 4 cells apart, like Hummieee said, I’m cutting off the “4 packs” and then with small flush cutters I’m working my way through each weld point.
Some do seem to leave tiny holes. I don’t know if I need to worry about those. They don’t seem to go through the cell body, just through the plates from the positive ends on some.
1 Like
Not much we can say…we have no idea what’s going on underneath those plates. Even the tiniest (actual) hole is unacceptable though.
No way in hell I’d use those cells as is, not knowing anything, but if the plates are not original (I don’t remember if they are or not) then I don’t understand why they haven’t been removed already to see what’s going on.
If the plates are original then those cells are ruined and should not be used.
2 Likes
We’re good. Did some digging, literally, and some experimenting.
- The plates are original. They’re not coming off and they are the same on the original boosted battery cells too.
- The holes are only through the plates, they don’t go deep at all. To prove this, I took one of the old dead cells and did a rather scary test. I started digging. I stopped at a little over 1mm depth and it was still solid metal. That end of the cells is much more beefy than I expected. There’s no way any of those tiny holes go that deep.
So yeah, I’m 100% there’s no impact whatsoever when using cells with those pinhole marks (no disrespect to the person above who said they wouldn’t use these, they didn’t have all the info so better to err on the safe side).
The faint of heart, scroll away now and skip to the bottom two pics where I cleaned up the battery tray from all the leftover glue and prepared the 12 chosen ones
Going to start welding them next. More tomorrow.
9 Likes
nice pics and updates!
2 Likes
Trying to plan out how I will connect the cells. Bear with me for a sec, just to have these here so we don’t make mistakes.
So the max charge for these cells is 3.6v.
12s1p will bring the total charged voltage to 43.2v.
This is a Boosted V1 dual (not plus) rated at 1500W, this would mean about 35A max draw from the pack. Will probably never use it right at the top rating, I’m thinking more like slower 10-15mph cruising at most.
Having said that, 0.1mm x 7mm wide nickel strips should be enough in single layer for the series connections between the cells.
On the other hand, not sure how to handle the main ends where the pack connects to the BMS. Do I just stack a few layers of these strips (unfortunately I don’t have any thicker ones at the moment). I also don’t recall what thickness strips Boosted used for the main leads. I need to go dig through the trash bin, might find them since I cleaned up the BMS.
1 Like
I actually thought the og boosted was a 16S1P A123. huh never really checked.
I sat on what’s the best way to connect the cells in series.
I think something similar to how Boosted engineers did it is the way to go with one change. I’m not going to shape nickel strips exactly like they had to match each cell connection on the BMS. It’s slightly easier and probably less chance of a short if I use wires. Should make more sense from the pics:
1 Like
Ok, I think the hard part is done. All the cells are connected correctly and we’re reading 40v at the ends of the snake. Tired, will finish wiring up the BMS tomorrow.
2 Likes
Just a bit of progress today, I put the BMS in place and prepared the pads.
Before connecting everything I’m still thinking about the main connections from the pack to the BMS. One option is as I set up currently: soldered a short 12GA wire to a small piece of nickel strip which I could weld to the pack. The strip is only 0.10 x 9mm (might be 0.12, my calipers are not that great). Could this possibly work for around 25A?
Fattest balance wires I’ve ever seen
If ur worried one nickel strip isn’t enough stack another. I would for sure
1 Like