Recent content by Boulter EV

I'm guessing the reason you would need to increase battery mass to change voltage is because your cells are huge and you only have 1 in parallel. @liveforphysics. Higher voltages nearly always means better efficiency and better power density. But to actually capitalise on this you need to have...

Wise to steer clear of RC stuff then if it's a serious build. In my opinion 18650's are the best choice when buying new if you don't mind the complexity of construction. You're right that you need to choose the right cells but LG,Pano,Sony and Samsung all do a decent automotive spec that is up...

Hello, Lots of options. Depends how good you want it and how much you want to spend. Take a look at my thread: https://endless-sphere.com/forums/viewtopic.php?f=10&t=85758 This is a 14s 55ah pack..... It would fit inside an xu case with room to spare. It would be about the best you could...

Hello, welcome to the forum. What interesting machine! What is the race? Is there a reason you're limited to 24v? The easiest thing to do might be to increase voltage and change the gear ratio? I'm sure if your motor is rated at 24v it'd be ok at 36 or even 48.....

As a plus point for hub motors you have none of this to worry about!

Just to add my 10p in, hub motors aren't just heavier, they are also unsprung mass, affecting the ride and handling. With a separate motor you have more flexibility over you rear axle design, but by far the biggest advantage is what John says, higher motor speeds equals better efficiency and...

Hi BB, like macribs says It's only valid in the UK. For this to be registered in another country it would have to pass the local tests. Which for most EU countries shouldn't be too difficult. I am looking into homologation for within the EU, but this is likely to be just something I...

Thanks UKPhil! I've not had any problems getting the bikes through an MSVA as all the parts exist. What I have been developing is a way to keep it premium and light so I've made some special things which I'll share on here shortly. More and more things are available, since I got my first...

this is really great work. I also can't remember the last time I heard the word 'gurt' and it really made me smile!

I've been reading your arduino cell balancing thread, I'm not going to comment on it yet because I've got about 6 months more to read but I'm looking forward to finding out how you got on! Because your using relays can you active cell balance? Or are you still using the top down approach?

Hi there, this switch cannot replace a contactor I'm afraid. A contactor is designed to switch in a controlled environment so that the sparks are unable to oxidise. A contactor will also be controlled by your BMS so that it can safety disconnect your battery in whatever conditions you deem...

Hi bobc, thanks for the comments! I am intrigued at what gizmos you're tinkering with!

Ah ha, good spot! I didn't even know this was still there! Yes, this was a while ago, first bike I got road legal to prove the concept. I used turnigy batteries at the time but decided to build by own packs as there was nothing, and there is still nothing available off the shelf that's good...

hi there. This bike doesn't classify as a self build. Because I have a company, this bike counts as a new vehicle. In the U.K. you can do a single vehicle type approval and then you're ready to roll. It has a number plate with current reg etc. I use a company called lexham insurance. They are a...

thanks Jim! Great to hear some feedback. I have a few shots of the build in progress that I'll post soon. I do plan to make a small number of bikes to sell soon but in the U.K. only. I may also sell frames on their own if people are interested.