Angus Digital

Strangely enough I did actually use some stanley knife blades to practice on before I went onto welding cells for real.

I really appreciate your knowledge and advice as I'm relatively inexperienced when it comes to cells, batteries, welders etc. I will check out the links...

I really fancy those Samsung 50E 21700's

Yes I take your point about the positive and negative connections being close together, but the beauty of doing drawings first and then posting them on forums like this is that I can get feedback. I'm pretty certain I can re-design the layout so that the terminals aren't so close together or even at opposite ends of the battery... I'm on it.

Maybe I'm asking too much but, it would be nice if the manufacturers of cell holders be it for 18650, 21700 or 26650 cells etc, would at least provide a diagram of how one would typically configure some cells into their products. Because of the shape of many bicycle frames it's not always easy to just install a square or rectangular battery pack which makes for a simple X,Y matrix layout I know that there are a few combinations possible for a given cell holder but it can't be that taxing to just at least have an online link with a page of battery cell combination graphics say for 36v, 48v or 52v batteries, (for e-bikes) I think those voltages are the most common although I know there are others. I have put just one set together here on my computer with a picture of the cell holder in question but it took me absolutely ages. Hopefully I haven't made any errors. Correct me if the pictures are wrong.

Thank you for the advice, I will be spending over £70 for sure so I'll be checking out Fogstars' website later to start with.

I see that Fogstar seem to be coming up time and again as a reputable supplier. I don't want to be spending any money except on genuine cells from reputable suppliers. Fogstar appear to be the way to go, among others...

Sounds promising. Is there somewhere reputable where I could obtain these P28a cells? I've just seen these cells online and the price varies wildly from different suppliers.

I see what you're saying, good point. There are so many factors for me to consider...

The reason I'm making such a big battery is because I sometimes have to make short trips as part of my work to trade counters etc, which are all within five miles of my place of work, and I wanted the option to do that and still be able to get home at the end of the day. I plan to use pedal assist not just throttle. I do have the option to charge the battery at work but I was hearing a lot about 'range anxiety' when I first became interested in e-bikes a couple of years ago so I just didn't want to be caught short bearing in mind I had no real idea how far my now soon-to-be-finished project could potentially go. I was seeing various theoretical figures of how far my e-bike could go depending on various factors so thought it might be a good idea to try and get a battery pack bigger than what I actually needed and maybe give myself some headroom without possibly having to charge the battery during the day. On top of that there is a fairly steep hill about a quarter of a mile long on the way to work and I wanted a battery that would deliver the power I needed in combination with a motor that wouldn't over-heat on the way up which is the reason why I went for the BBSHD. I am more interested in range rather than speed even though a few extra MPH on top of what I would get on a conventional bike would be appreciated.

I did take a look at the pedelecs law section. It's a minefield out there when it comes to uk laws and regulations concerning e-bikes. It appears that I basically have an electrically powered motorbike, which means I need mirrors, indicators, headlight, crash helmet (I already have the crash helmet) and a plethora of other requirements in order to become street legal. However, I'm not put off. I've come too far now and I'm looking forward to eventually taking my e-bike on the road. (legally)

This is some very useful information as I have not yet made my maiden ride yet. Thank you.

I already have the motor and I really don't fancy buying another one. I did get a programming cable in order to limit the power output to comply with the local regulations. As you'll be aware the stock motor is at least 1000 watts. I believe for legal street use the power should not exceed 250 watts and a top speed of 15 mph (in the UK at least).

It's not looking good is it ?, in terms of using these cells in my battery pack. However, the good news is that I have at least three old power tools that have dead ni-cad cells in. I could always modify the batteries and power the tools with the lithium ion cells I already have and give my old power tools a new lease of life. I've seen many tutorials online of how to do this safely.

I will be checking out Fogstar.