I started out with a really common contactor choice, the Albright, basically a golf-cart, open style contactor that uses pack voltage to power up the coils. I think it’s time to move up to a little better choice – the Tyco LEV 200, a sealed unit that uses 12V for the coil voltage – for a few reasons. I like that it’s sealed. It’s “designed to be the lowest cost sealed contactor in the industry.” I also like that the contactor control switch will be running 12V instead of over 80V. I don’t really like the idea of running that kind of voltage to my handlebars, no matter that it’s running 14awg wires that will likely burn up before anything nasty happens.
There is a model, the EV 200, uses a feature called the “economizer”. This allows the contactor to stay closed by using PWM (pulse-width modulation) rather than a continuous current, which saves energy. Most of the muscle needed to close the contactor happens when you initiate the switch, and holding it closed is just a matter of maintaining the, well, “pressure”. This causes some trouble with some controllers that do, in fact, control the contactor themselves (Curtis, I believe) where you have to bypass the economizer (or presumably turn that feature off in the controller?), but since I’m running a controller that doesn’t have that feature I’m safe. However, it’s a little more money, and although it’s an elegant idea, it’s not really a big priority for me. (Yeah, I’m cheap. I’m also easy, but that’s a different story.)
Here is the product page. It also comes in a side-mount configuration, perfect for my bike. It’s also available from DigiKey and Mouser… but the folks at EV Source have it for under $100 (along with some good information on the line of products). Order up!