ElectricMotorcycleForum.com

a battery that can hold several kilowatts of stored energy, even with a modest 2 or 3 volt difference can push hundreds of amps across the connection, and continue for a while until its stored chemical energy has exhausted into the other battery to bring their volts to being equal in which case the current will slowly stop flowing as the voltages equalize out.  this will severely stress the batteries, the bms and other components.  lithium does not like this, at all.

you have to remember with lithium.  at the top and bottom of the curve, yes a few volts, holds little energy, but lets say from 50 to 80 percent charged, a nice middle range, there's a lot of power in those 2 or 3 volts of drop.  when you hook all those batteries up in series, you have the ability to push some hefty amps, for a while, to equalize it out.  even a 20 second inrush can be enough to pop internal protections or cook stuff that isn't designed for that kind of load over time.  high current can generate high heat real fast too.  if you have a weaker battery, that may cause a hot spot, which is enough to start a slow cook off, it overheats there, it can't get rid of the heat fast enough, starts stewing,  then finally cooks off.

ive seen more than once where a tech will touch something, huge current thru pack for a second or two, he jumps, breaks connection.  you ok??  yah, what the hell dumbass... derp. is the pack ok... it looks ok,  well keep an eye on it...... feel it.... it's a little warm but nothing bad. ok...  5 minutes later the thing starts smoking, the packs are swollen and its growing, ok get that fucker outside now!   a minute later its on fire as the cells sympathetically pop off one by one.

now, can you get away with it, yes, depending on your situation it may not be a huge issue with your setup, but this requires you to have the brains to understand YOUR setup and know it's behavior, and that it is safe to do, but overall, is not a good habit to develop.  The idea of using a light bulb or some sort of current limiting device in line is an excellent idea, that many use all the time.  this lets you see the current flow as well as volts, so you can monitor and after say 5 or 10 minutes when the batteries have equalized, then you can directly connect them w/o a limiter and they'll be fine.

lead acid, nicd, nimh, nife chems,  a few volts off, ok you heat things up a little, they'll get over it, but lithium.  you are playing with fire.. literally.

aaron

Please remember that these are stationary voltages. As soon as even a small load comes on the higher voltage battery its voltage drops. And vice versa for the lower charged battery. As soon as it starts to receive charge its voltage increases. Battery receiving charge has relatively high ESR. So small voltage difference has little effect.

It really depends on what type of sealant this is. Once you figure out the type of sealant (like that's easy  you can look into the data sheets what solvent would be most effective.
I've had good results removing some sealants (and glues) by heating them. Try your oven to get the part warm to throughout. Heat only makes the glue soft, it does not dissolve it. I've also used liquid silicone removers on others (Silocone removers tend to be found in the plumbing section (isn't Carl Moller still large in Denmark?)). For one glue where I really had to remove the glue without damaging the part Gasoline was most effective. Acetone is another powerful easily available solvent. Often found in your wifes/girlfriends cosmetic shelf, make sure it's the real thing, not environmental safe replica.
If all else fails you can sacrifice the part, draw/redesign it in CAD and have it custom made. Either in your own (or one of your friends) 3D printer or use something like PCB-Way which is one of many companies offering bespoke one off CNC manufacturing. Aluminium tape might also work.
The LED module itself is most likely available from RS in Denmark.

There has actually been a bit of a renaissance in the past year or two with tabless cells that enable a very low ir and higher discharge than youd get with the more conventional 'power' cells. Take a look at (to name a few) the reliance rs50, tenpower 50xg, and the eve pl50 (though this cell has some issues with some particular batches its fairly solid overall). Theres also the molicel p50b which isnt tabless but it and all the afformentioned cells do at least 10c discharge and 2c charge. The older power cells like the p42a, p45b, samsung 40t etc are pretty outdated when compared to tabless cells (though they can be had for very cheap, thats mainly why Im using p42as for my projects!).

Technoligia is always improving. Today's state of the art is tomorrows outdated technology.
It's important to check all the parameters/specifications, buy cells from a reputable brand, from a respectable seller, and do your basic homework. It's not just volts and amperes. It's also chemistry, "resistance", cooling, energy density (Wh/kg), and so on and so forth (and C). There was a video circulating recently where results of testing of hundreds of cells from various manufacturers was revealed, including x-rays of the cells. Alarmingly high portion did poorly. Some were dangerously bad.
As you point out, the higher current cells tend to be more expensive. An inexperienced person asking for an advise in an internet forum and only looks at Ah might end up with more easily available but less suitable cells. If not counterfeit cells that fail within days.

Personally, if I was discarding all the cells in my Zeros battery, and rebuilding from scrap, I'd use large pouch cells. Each cell about 20-40 Ah and around 3,7 V. That reduces connections (work, materials) and greatly simplifies build. Last time I checked I could get all the materials (reusing the BMS and housing) for 13 kWh battery for less than two grand.

The first gen Zeros had some creative battery rebuilds. I'm not aware of any for the newer bikes. The issue is that they are usually potted so rebuild (as in each cell being tested and replaced if low on specs) is difficult. Full rebuild, that I have personally looked into, is less difficult. But you need to know what you are doing. There is a lot of power potential in those cell. If that power is released in uncontrolled manner it can cause damage or fire.

That user interface and options look awesome.
Nothing wrong in getting help from AI, it is constantly improving.
Norwegian? I have some friends in Haugesund.
I'd love to have a look at your documentation. Documentation is a large part of my current job.
Does your controller 'speak' I2C or UART. If so you can use one twisted pair for short distance communications instead of eight wires. Could be hardwired if you don't intend to disconnect them often.

maybe you should ask AI

Surely you're pulling my leg, sir. I did ask AI.

If you really care a lot I will suggest coasting down a hill and seeing how fast you get going.  If you have a timing system and a few eyes/sensors one could get more exact doing no chain vs the other ways.   See if worn sprockets and chain is different from new ones.  What do  you guys run on Energica bikes x ring chains?  It is 1/4 inch wide sprockets 525 not 530 without looking it up.

Coasting has many outside influences that can affect the results. For example tire pressure, wind, etc. When the margins are narrow those outside influences can skew the results.
I strive to always read the actual tests reports. It can tell you a lot about the accuracy of their results that other (maybe biased viewpoints) overlook.

I chatted with AI regarding the efficiency number that are on the internet and are widely quoted.
"No peer-reviewed or independent laboratory studies specifically testing motorcycle belt and chain drive efficiency under controlled conditions were found.
The most frequently cited data comes from a 2012 Friction Facts laboratory test, but it was conducted on bicycles, not motorcycles"
Test here; https://www.cyclingabout.com/wp-content/uploads/2015/09/Gates-Carbon-Belt-Drive-efficiency-vs-traditional-single-Friction-Facts.pdf

In short.
Gates Carbon Drive vs. Chain Efficiency Test
Chain loss: 2.92 watts (average)
Belt loss: 3.93 watts (average)
Tested at 250W load, 95 RPM, with belt preloaded to 85 lb (per Gates guidelines)
While this test is rigorous and repeatable, it does not simulate motorcycle power levels (typically 50–150+ hp vs. ~0.3 hp in the test). The mechanical principles (friction, hysteresis, preload) are relevant, but scaling to higher torque and speed may alter efficiency outcomes.

Some motorcycle-specific claims (e.g., 97–99% efficiency for both systems) appear in manufacturer-backed or trade publications, such as a 2025 test by Gates and Universal Transmissions, but full methodology and raw data are not publicly available.

I know, lubing chains is a somewhat emotional issue for some people, similar to tires and oil 

Nevertheless, it sometimes helps to understand what chain lubing should do and what it is definitely not doing.
Refer to the attached picture.

No chain lube in the world will go underneath the O-rings (or X-rings or whatever shape they are) and replace the lube put in there in the factory.
Because these O-rings hinder the original lube to come out, they also hinder fresh lube to go in.
This lube will deteriorate over time due to stress (hydrocarbons cracking) and hydration (water molecules diffusing through the O-rings). By these mechanisms the lube is increasingly not functioning properly anymore. On some point steel rubs on steel and from then on it is a steep downhill path. The chain is lengthening, wearing out the sprocket and chainwheel which is also stressing the chain even more.

By lubing the chain you can only try to get fresh lube under the rolls (marked red in the picture). For that you need lube with penetrating characteristics.
Thick chain grease is not doing this, it might help to protect the lube under the rolls and saves the outer appearance of the chain against corrosion, but that's it.
So, excess lube on the chain only makes your bike dirty and your wallet empty.

Currently I am at 102,000 km with the bike and on my fourth chain (36,000 km), using dry lube chain spray which is simply spoken PTFE suspended in a penetrating liquid which evaporates, leaving the PTFE as a lubing film.

In my view spinning the wheel at high rpm while spraying the chain is not a good idea. I prefer turning the wheel by hand.

For me regular oiling of a chain is mostly to keep the rust away. It keeps the outside of the O or X rings "wet". Thereby reducing friction between rubber and metal. It reduces oxidation of the rubber. It also reduces amount of fine dust articles that reaches the rubber where it meets the metal. This slows down wear by some degree.

An old trick to extend life of your chain is to clean it thoroughly with Benzine (Gas, Petrol) or Diesel. Put it in a pot with motor oil. Heat it to 80-90 degrees Celsius for half an hour or so. Let it cool down. This forces air and dirty grease past the seals when warming and draws fresh oil in when cooling. I doubt it will be very effective today, but some used to do this every year. Clean the pot and put back into the cupboard before the wife gets home.