I doubt it’s worth the hundred dollars to try and save these cells, unless you are just trying to make a battery building lesson of it.
you’ll spend all day on it and in the end, you’ll have crusty old cells to work with. THEN you’ll spend the same time building the battery as you would with new cells…
it depends on the cells, but generally with a pack that crusty, usually better to start over 
Note taken, and agreed. At the end of the day I would not even save much by keeping the cells. Because it is only 10s2p, and Samsung 30Q are not that expensive. I will still be saving a lot by salvaging the case, BMS and connectors. I can scrap all the old cells and get everything I need for under $150.
@iamasalmon & @Andy87
I have made up my mind and will be responsibly recycling the old batteries. As for re-building the pack with new cells, I am confident that I can rewire and desolder the connections without trouble.
In terms of keeping the new battery pack from breaking… I see a lot of people here raving about fish paper and also tons and tons of kapton tape. My old pack only has thin strips of broken (probably cheap chinese) kapton tape.
I would like to do it the right way and ideally improve upon what I got from the factory, any tips there to make it last?
I would disconnect the plug for balance wires on the bms and than desolder the main leads.
The other way round shouldn’t be a big drama either as long as you directly isolate the wires from the cells. Lose wires can touch each other accidentally 
Note taken! will definitely make sure to isolate the wires when working on it, just wrapping some electric tape should do the trick, right?
And ah “Plug for balance”, guessing that is the plug I thought gave power to the BMS, anyway yes I will unplug that aswell.
Fishpaper on the positive terminal and between the p groups is always good. Also between bms and cells I would add a layer of fishpaper.
You could conformal coat the bms for some extra water protection or seat everything covered with neutral silicone in the battery case. Might want as min check the sealing of the battery box. Maybe you can improve that somehow or replace old sealing if the rubber is damaged etc.
Thanky you!
I understood (don’t know way) strip layer on each side.
Are you thinking that one layer will be enough for max 60A?
Yes, even masking tape will do the job. It’s anyway just for the time till all is in parts.
That’s the one.
For me it did work out well so far.
That’s 2x 7mm 0.15 nickel on the positive terminal and 3x of them on the negativ.
You will not draw 60A constantly out of the pack. If you would, you shouldn’t go 3p only
If you worry it’s not enough you can use that diagonal strip which you showed in 2b. It’s a bit more wide nickel. Definitely enough there than.
Thanks for making it clear with the image, I was correct 
seems like a fairly straight forward process, I have read other guides in this thread, so not just going off of our messages.
I will make sure I can get a hold of a spot welder first and foremost, and then start buying fish paper/nickel/30Q batteries/battery holders. and I am sure this will be a fun little project to put together.
I have repaired many other electronics, so I think batteries can’t be too difficult. I am optimistic. Another big perk I see if I make it myself is that I will be comfortable diagnosing it in the future if problems creep up again.
I will go with two 6355 with 30A each one.
I want stay with fit cruoser deck so the space is resuced.
70% is flat, so 3p 30Q should be enough.
Many thanks for resolve my doubts!
You’ll see a fair bit of battery sag running a 3p 30q at 60 battery amps.
The pack you showed used kapton tape incorrectly. It is broken because it was worn through, probably by pressure in those spots and constant vibrations.
Kapton tape is good for high temp, high voltage electrical isolation. It doesnt have a very robust adhesive (compared to a lot of other heavy duty tape) because its not really meant to hold stuff together. Most importantly, its not abrasion resistant at all, because its not meant to be subjected to abrasion.
I actually saw someone make the case in this thread a while back about how there really isnt an application in esk8 for which kapton tape is perfectly suited. Nothing that we are isolating should be getting hot enough to need the heat resistance of kapton, and we are not using high enough voltages that the high-volt isolation is needed either.
Pretty much all of our electrical isolation needs are better suited by fishpaper. It is highly abrasion resistant, and if you got the good stuff, it is more that heat resistant enough for esk8 use. (If anything in your esk8 is getting hot enough to hurt your fishpaper, you have much bigger problems).
Thats not to say that Kapton is useless in esk8. It works well as a thin, lightweight barrier over electrical terminals that you also separately isolate from abrasion.
In the dirt surfer’s picture here, you can see that he used Kapton over all the exposed terminals of his battery, but covered those with a sheet of acrylic that is both abrasion resistant and electrically insulating. Really the kapton is only there for peace of mind and in the very rare unlucky instance where something conductive slips between the acrylic and the battery. The rest of his battery (all the parts with a chance to be in contact with anything else in his enclosure) are isolated with abrasion resistant tape (he could instead have used fishpaper here).
If anyone else has anything to add or correct, please do so. All that info i spouted off is just what I have learned from this thread lol. Everyone has different preferences when building batteries, and there are many ways to make a perfectly safe pack.
Now i using 2P T30 and give me max 70A. I using Ackmaniac and i never see to be close to the max, so i think Q30 will be enough for my ride ~25KM/H.
Noob question here, but if you set a battery Regen in your vesc, is an in-line discharge bms needed to properly redistribute the ‘regurgitated’ mAh, or is the power returned to the battery so small that it doesn’t really matter.
With my 6s pack I have Regen set to 0a, and it brakes just fine, but I have heard that to have strong brakes at higher rpms, you need a set Regen to strengthen the power of the brakes, or get any at all.
Is that true?
What do I have wrong? Can the battery bois elaborate pls
It doesn’t matter. As long as you set your vesc up correctly it won’t overcharge the battery.
How does the vesc control overcharge of your battery?
When the battery voltage reaches the overvoltage cutoff set in the vesc tool, the vesc will not put any more current into the battery. It won’t stop a charger from overcharging the battery if the charger isn’t putting out the corect voltage, though. That’s what a BMS os for.
That means that if you go down a steep hill with a full battery, you will lose your brakes. Be careful.
That doesn’t protect the battery from overcharging individual p groups if they are out of balance that’s what a discharge bms would do. Either way I personally would rather want my battery to be a bit overcharged for a minute than that I do not have brakes while riding down a hill
If you have a BMS, then every time you charge the battery it balances the cells. That’s one of the primary jobs of a BMS.
Unless you have P groups with wildly mismatched capacities, they won’t drift enough during one charge cycle to overcharge a single group due to regen braking.
