Endless Sphere

Welcome, Nick!

Thanks, I was familiar with annealing steel, but when I read about copper annealing, they did not specify that it could be cooled rapidly.

Series-hybrid is my favorite drivetrain for a plug-in electric EV. That being said, a pure series hybrid would be easy to figure out, and as far as retrofitting, all it takes is money...lots and lots of money. My son has a Chevy Volt, and the battery is small, maybe 80 miles? But the thing is, he dr...

I'd like to make a note about this, great stuff. The positive end of 18650 and 21700 cells are very robust and can take quite a bit of abuse when considering various methods of bus connections, such as spot-welding, soldering, and others. However the negative end is sensitive to heat. Using magnets ...

For anyone who is curious about what these modules could be used for besides an ebike, there are a lot of children's toy electric cars that run off of a pair of lead-acid wheelchair batteries for 24V. A seven-cell in series pack of 18650s of the same volume of the original 2S SLA PACK would run twic...

Doctor Bass, one of his first hot rods...

I'm not a fan of the X form of your series/parallel connections. That being said, the series connections are handled by the nickel strips and their welded connection to the cell ends. The parallel connections are where the two strips cross to form the center if the "X". Perhaps consider so...

Your BMS is not balancing your pack. It's only bulk charging Get a small 12V filament bulb from an auto parts store, solder wires onto it's two contact points, and attach the two wire ends (alligator clips?) To the positive and negative of the cell groups that are 4.22V. A large bulb (*headlight) wi...

High current passes through the series connections, and that's where the copper needs to be. The parallel can be copper, but there is no benefit to using copper for parallel connections.

Have you tried the nickel/copper sandwich method for series? Have you tried the infinite slot method?

There is a wide selection of hubmotors that would be up for any task given it. In an aero application where there is significant air-flow, i suspect a large Quan Shun /QS direct drive hubmotor (for small motorcycles) with 15ml of ferro fluid would provide the best weight-to-performance rating. The V...

The LVC wont work, but 60V battery capacitors (16S x 4.2V = 68V fully charged?) Are likely 100V caps.

If it blows, get another.

Frankly I'd buy another controller and keep the 60V controller with the 60V packs. Buy a new 72V pack.

How old is the battery? maybe it cant pull the amps it used to when it was newer...

An 800 ft rise on the commute suggests to me your best choice is a BBSHD. I have ridden many dozens of ebikes, and I have owned several. The one I have kept riding for five years is the BBSHD. You could save a few dollars and a few ounces by getting the BBS02, or possibly the even smaller TSDZ2. BUT...

If the negative tabs on the inside have not come loose, you'll be fine. You can individually cycle test them, and put them under load while looking at them with a cheap heat camera, to see if there's a hot spot.

Luke, the Zero motorcycle battery that your team designed remains to this day a respected standard that other companies would do well to embrace...if I were single, I would jump at the chance.

Here is a build where the ebiker wanted to cut his frame and weld-in a proprietary build. This will give you an idea of what that would entail...(The steel in this alignment jig is easily removable after welding) https://www.electricbike.com/adding-bafang-ultra-frame/ https://www.electricbike.com/wp...

Thrust block,

even if the RPM's are acceptable for direct drive, maybe plan on a belt drive to a shaft on the side, with a thrust block on the end of the separate shaft?....

I'd look into a wrecked Zero motorcycle. I'm sure the motor controller, battery, and throttle would work very well for a boat. If it turned out to be too small, youd likely have no trouble selling it, and if it's too big, it's a good experience. Plus again...once you build the ideal system, you can ...

On the negative end, avoid welding to the very center.

On the positive end, the entire surface is very isolated from the interior and you can weld to any part.

Yeah, it's the plasma. I can't see any way to make a focused plasma jet for a few precisely timed milliseconds for under a few thousand dollars...yet.

If its an LLC, the person cannot be personally sued for the liabilities of the company, but the battery building company can have its assets seized to satisfy the judgement against a lawsuit that was successful (or a spurious lawsuit brought by competition in order to get paid $15,000 to drop the su...

Concerning laws, I would suggest forming any such business in the US as a welder-rental service, and the rental company rents the machines to the battery building company. You don't have to be "at fault" for someone to sue you, and there are cases where liability insurance paid $15,000 for...

Definitely plan to “go commercial” with battery packs for go carts, E bikes, and electric motorcycles at some point in the future

Boats, forklifts, home power back-ups...

You will be asking the battery packs to supply occasional peaks of 30A, that is the important number. If the pack gets hot, or the output has significant voltage sag, then the battery should not be used in that application. If they are authentic Panasonic cells, that's good, but all the major 5 cell...

Contact Keith at his Facebook page. Ask him. He might be able to ship one and cancel the order from Germany.