I agree with Evan.
3 Likes
The e-bike controller may not have itâs own low voltage cutoff either. Discharge bms sounds like the way.
4 Likes
Iâm looking for an experienced battery builder in the EU for some long term contract work.
Preferred qualifications:
- An experienced battery builder who holds themselves to all of the âbest practicesâ of esk8 batteries
- An experienced esk8 technician
- In business building/selling batteries*, and looking to expand that business
- Able to dedicate a consistent amount of time to their business as demand scales, and meet production deadlines (i.e. not over-constrained by school, day job, etc.)
- A legal permanent resident of an EU member country
- Experienced in shipping batteries and esk8s across the EU (li-ion shipping license not required, but definitely a plus)
If you (or someone you know) meet some or all of these qualifications, please PM me.
Thank you!
*to clarify, the size of the business doesnt matter. If you are a hobbyist doing this as a side gig, thats fine too. We just dont want someone for whom this will be their first contract. Gotta have a history of happy customers to be considered.
16 Likes
Our priority is EU. We may be interested in a contractor in the UK as well, but for the moment our focus is Europe.
8 Likes
I do actually ship the majority of my packs out to the EU, its not really any more expensive for anyone in the EU as compared to elsewhere, with IOSS there isnât too much difference but if you have some kind of legal structure already setup for an EU resident then yea I wouldnât be able to do it.
If the project is non bespoke I also have an EU based 3PL that could store and ship
3 Likes
i would suggest @Simeon bc he is professional, reliable, fair pricing and builds rock solid batteries.
3 Likes
Hey guys.
can we talk a bit about the status of the pack I built for my flux?
I am curious about itâs health.
I am more curious if I need to change any behavior.
Should I consider different ESC settings?
Should I charge differently?
Should I change any BMS settings?
This is the biggest pack I have builtâŚ
It is a 12S10P30Q
It is almost a year and a half old.
It is on my favorite board so it has seen a lot of miles.
At one point I got 31 miles out of this board.
Probably more around 27-28 nowâŚ
I have concerns about P groups 1 and 8 that usually are sitting lower than all others.
Also a couple are seem to usually sit higher.
Iâm going to show a bunch of screen shots of the BMS and hope they make sense.
These are at various different stages in recent days.
Here is today.
Been sitting charged a couple days. The delta jumps back and forth.
I have it set to balance when not charging.
Here is the day before yesterday.
Here is what it got down to on a recent ride and then what it charged to.
Here are my bms settings.
here are my ESC settings.
here is my babyâŚ
3 Likes
0.2v is a massive voltage delta, group 1 is very likely to have a dead cell, its way more than 10% difference in seemingly every screenshot
1 Like
Might be worth trying to manually bring group 1 up with a cc/cv bench top power supply and group 5 down with a resistor, then see if it stays balanced over a few charge cycles. If not probably a dead/dying cell.
2 Likes
so say a cell is dead.
does that create a dangerous situation?
or can I still use the pack and just have slightly reduced capacity?
I guess what I am truly after is if there is a lazy manâs approach to keep using this pack?
the thought of really opening it up physically super bums me out.
It could.
Assuming a cell is actually dead, youâre pumping energy into and demanding energy from a chemically damaged cell. This will stress it more, and since the condition of the cell canât be known, itâs hard to say what will happen.
Or it could be that more than 1 of the 10 cells are underperforming.
Or that welds are broken.
Hard to say unless you physically go looking.
You can of course continue to use the board normally, and just roll your dice.
The real likelihood of it ending catastrophically is unknown, but I generally tend to doubt itâs a high risk. I say that because of the continuous stream of scary trash batteries I see that keep on running somehow.
As for a lazy approachâŚIâm not personally the type to approach a battery of 120 cells in a lazy way. There are of course ranges of tolerance between convenience and risk, and youâre the only one who can make those choices.
âI donât want toâ is usually a decent enough reason for most folks to just leave things as is until they fail. However that may be.
The 12s4p 30Q pack in my Sportster still runsâŚand to be perfectly frank, I have no idea what the cell groups look like. Itâs 2 years old, I get 9 miles, and itâs probably a functional pile of trash. Whoâs to say?
1 Like
yeah dude.
very tricky.
I am closing to finishing the new pack for the Flux. a 12s9p BAK.
but I totally wanted to do something with this pack.
what are some other viable less lazy scenarios:
I take out Pgroups 1 and 8. make a 10s pack(so sad)
I take out Pgroups 1 and 8 make new ones with new cells and have different ages on there? ( not sure I can buy 20new 30qs)
I take out Pgroups 1 and 8 and make new Pgroups with some of the used 30qs I have laying around( I have 90 + )
I am not sure I have mentioned this enough⌠but it is worth re statingâŚ
Esk8 batteries are dumb and I hate them. .
2 Likes
Well thereâs your problem 
I would vote for this option, even though I understand itâs not ideal. However, itâs worth pointing out that groups 1 and 8 are not the only groups getting out of balance, they are just the worst ones. If I were you, I would open up the pack and check the welds on every single cell, as tedious as that sounds. If all the welds are solid then itâs your cells which are bad.
2 Likes
yeah dude.
the regret of building this pack with 30q runs pretty deepâŚ
at the time I really didnât know any better.
I super hate welding on 18650sâŚ
fuck fuck fuck.
taking apart and inspecting the whole thing sounds so incredibly painful.
tossing it in a lake also sounds painful.
I probably have not mentioned it lately.
but I hate esk8 batteries.
2 Likes
slides business card across table
4 Likes
Whoâd you use? These look nice. I dig the unbleached paper.
4 Likes