Recent content by tomv

I'll just make a case for those batteries. Unfortunately I didn't try this setup myself yet, but looking for good deal and will do so. Tesla car uses such cells (high energy, low power). The idea is that they are cheaper and have double the capacity than similar tool pack cells. So assume...

1w led is more of a "be seen" than "see the road" type. it will not compare to bicycle halogen setup. if your old halogen setup was mr16 type - there are led mr16s that fit. they work off 12v and provide up to 3w of light. I found those convenient, cheap and easy to use. 2x led 3w mr16 are...

OMG! I have drool all over my keyboard. To put this in perspective: 5545 has 4.5kw/kg Best aircraft engines are about 1kw/kg (Rotax 912) without necessary fluids Crystalyte 408 is 7kg about 1kw so 0.14kw/kg This motor has more than 30 times better power density than best hub motors.

Hi Mark, That's very exciting! I would buy a motor that would fit bikes like Honda Innova or Sachs MadAss. I'll also keep the motor under 4kw peak as to stay within EU regulations for mopeds. For me a Crystalyte X5 would work perfectly, but it would need to be laced to motorcycle rim...

They used to make cells for A123 up until 2007 but no longer do. This is related to them being sued by Hydro-Quebec for patent infringement together with Black&Decker and A123. They do not manufacture high discharge cells at this point of any kind, but plan to. You can read it all in all gory...

Side illumination now is surprisingly good, similar to the halogen car light. Lens rated for 30 degree angle actually throws lots of light to the sides too. I'm not sure how they rate them. The problem with doing a nice closed case is heat. Even now, everything open, heat is borderline...

Next steps will be to waterproof this one and to build rear light out of red 1W leds. I'm undecided if I should use lenses for them or not. Should I keep leds covered with clear or diffuse glass? The goal is to achieve maximum visibility. Any ideas?

Now for the 3x 3W light build. Parts are: 3x 3W white star leds 2x 10 degree lenses 2x 30 degree lense PowerPuck buck converter Milwaukee V18 lithium tool battery 3mm x 25mm aluminum bar 1mm think aluminum foil Heat sink grease Assorted wires and screws The key to making it work is heat...

Now a comparison. All pictures are of the same view, taken with the identical camera settings but different lights on. Camera was set to f/3.5, 1/60s, iso 1600, 28mm equiv lens. So view is pretty wide. 1) 1W Catye Led. Very narrow angle of view and pretty much not much light at all 2) 3W...

I've built myself a nice 10W led headlamp and did some quick tests. I spent quite some time doing wrong things, so hopefully this will be a useful recipe for those who are thinking to make something similar. Also here is a quick comparison with a bunch of other lights. Background. I've been...

Forgot one vendor. Valence batteries are used in mass market product (Segway), and they do sell their battery packs in useful capacities, with BMS and robustly packaged. But they are VERY expensive.

The situation with lithium batt sucks. But while we keep waiting you might enjoy reading what I found out about this. Skip the rest of the post if you look for any useful info, it's just for amusement. LiMn is as safe as LiFe. They won't explode or catch fire if impaled by nail, heated etc...

You actually don't need to build anything. Milwaukee V28 batteries give exactly the same voltage as charged 24v lead batteries. They are 3Ah, 84Wh. That should give a range of 4-8 miles. Standard charger will charge in 1 hour (or you can charge for 15 mins and have range of 1-2 miles)...

I'm sorry that my post sounded like an attack on dedicated pack sellers. It's certainly great that some people serve e-bike industry whatever the price. I'm not saying the sellers mark up the prices My point is this: Lithium producers sell packs for $0.5/Wh I can buy for $2/Wh. So the...

Here's an interesting snippet in the news: http://www.autobloggreen.com/2008/08/26/enerdel-ramping-up-battery-production-to-supply-th-nk/ Th!nk has ordered $70 million worth of battery packs from EnerDel, which equates to about 5,000 units. Each pack contains about 27 kWh of power. So, that's...