Dampmaskin

Get a PCB holder made from metal. Convenient, much more heavy than the PCB itself, easily removable, reusable, leaves no glue residue. You can get them in different sizes and with different degrees of complexity so you can find the right one for your needs.

Ah, don't give too much grammage to such things. :)

Amperage sound silly because there's already a perfectly cromulent word for it: "Current". It even has 33% fewer syllables. (Also Wattage is silly-speak for power even though the number of syllables is the same.)

Time to read the documentation? Maybe it has a full fledged BMS. If that is the case, I guess it's just a matter of connecting the cells as specified in the documentation.

Remember to monitor and protect each cell group in series individually.

But if you buy them from ebay, maybe get double the rating you need. Because the sellers tend to exaggerate the ratings.

You can probably find them pretty cheap on ebay, and hope that the quality is ok.

But how will you keep the cells balanced?

Overvoltage using fuses? Overcurrent you mean?

One of the most important job for the BMS is to protect the cells against overvoltage, undervoltage, overcurrent, and to keep them balanced. It's a good investment if you want your cells to last.

Depending on the BMS.

Well, start with the BMS and design the battery pack around that. You'll probably need to make several groups of parallel cells, and connect at least 4 or 5 groups in series.

I find many e-cigarette shops sell 18650s for a reasonable price. And some of them have a reputation to protect, so they will often work hard to avoid selling fakes.

I would not buy Lithium batteries from Ebay. Way too risky. Better to find a trustworthy battery web shop in your vincinity. Or an e-cigarette, flashlight or hobby shop.

Also remember you need to charge the cells, and balance charging is mandatory. Either get a BMS that supports charging, or get a separate balance charger that supports the necessary number of cells in series.

They're top quality though. If you want to save money you can check out other 20A cells from Sony, LG, Sanyo or Samsung. A greater number of lower capacity cells may give you better bang for buck. But watch out for fakes.

You should probably increase the number of cells. Also, use a BMS (battery management system) designed for electric bikes. You will not be able to make a good BMS from scratch in your garage unless you're a power electronics pro, so just find a good one to buy. Then read the documentation, and connect the cells as suggested by the BMS manufacturer.

1000W is a lot for any battery. Are you making an electric motorcycle? Anyway, harnessing that much power from batteries in a safe and efficient manner takes some careful engineering.

Yeah, so you have some practical knowledge about how to use electrical compononts, while your question is clearly about getting a deeper understanding of circuits as a whole, and what makes them tick. Hence my advice. Good luck!

This question actually shows that do you not have a basic understanding of electronics, at least not on a conceptual level. Stop researching practical electronics, and electrical components like LEDs and resistors for a while. Instead start by googling Kirchhoff's laws, and read everything you can find about them until you have an eureka moment. Then do the same with Ohm's law.

Hmmm. I think I'm out of suggestions. Except maybe study the connector and the cable carefully under a magnifying glass until you spot the problem, whatever it may be.

Sure the black piece is all the way out? 2 or 3 millimeters?

Not sure, but it looks like you've got the sliding kind.

But some of them tilt upwards on hinges.

Most of them are supposed to slide out parallel to the PCB.

Is the end of the cable bent or curved from your first attempt? If so, you could try to straighten it out.

These connectors are a bit tricky until you get used to them.

Or else it could slip out a millimeter or two, and that's enough for it to fail to connect.

Ok, inserting the flex cable can inadvertantly tighten the black piece, preventing the cable from being fully inserted. So try this: Keep the black piece pulled out with one hand, while simultaneously inserting the flex cable with the other hand. You should feel the cable hitting the bottom of the slot. When you're sure that the cable is fully inserted, then you can tighten the black piece. And keep inward pressure on the cable until everything is tightly together.

They're usually not visible. The cable should "bottom out" inside the connector before you tighten the black piece.

It's not intuitive just looking at the connector. I learned it the hard way. For black screen, there's a possibility that you damaged the flex by bending it, depending on how fragile it is and how much force you used. But might it also be possible that you tried to insert it the wrong way around?

The flat flex goes between the black plastic piece and the PCB, not between the black plastic piece and the white plastic piece.