Everything you ever wanted to know so you can build an EV

Love to read your post on how you customized your scooter and i myself eager to do so as well. It just that i have zero experience on wiring and no knowledge on how the scooter actually works. I have just started to 'explore' my scooter and do some little research on how to upgrade my scooter. BTW i have a scooter which runs on 48v 500w motor. In order to upgrade my scooter, i had just bought a 60v 2000w chinese motor controller from alibaba site. The only problem is that it is nothing the same as my old controller. The wire color & number of the wires are not the same, the wire label is in chinese, although they try to translate it in english using the diagram, it is not the same and make it very complicated for me.

Ebuilt said:

God, can you please clarify a little bit more about how to bridge the kill switch with a 1k resistor so that I can stop sparking my battery everytime I reconnect it for whatever reason.

Are you just squishing the resistor end wires between the two nuts of the kill switch itself?

I have both on the way in the mail. Thank you.

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God...that's hilarious! I picked the name totally because it was snarky and irreverent. and from time to time I meet people on ES that take umbrage at the name...which is even more hilarious. I think they need to take a chill pill. I sure don't see myself as a "god" of anything.

anyway...back to your question...
The 1K resistor goes right across the screw terminals on the contactor. If oyu put a small switch in series with the resistor to cut all current flow, be sure to close the switch before closing the contactor. I think the current draw across the resistor is fairly negligible so I don't bother. Then again when off my EV's don't draw but a few mA anyway. The resistor wires could be directly put under the nuts, but there's a fairly good chance you will also break them off. I solder screw lugs onto the resistor wires. Be sure to cover the whole thing in heat shrink so you can't get shorts.

Lurzarac said:

Love to read your post on how you customized your scooter and i myself eager to do so as well. It just that i have zero experience on wiring and no knowledge on how the scooter actually works. I have just started to 'explore' my scooter and do some little research on how to upgrade my scooter. BTW i have a scooter which runs on 48v 500w motor. In order to upgrade my scooter, i had just bought a 60v 2000w chinese motor controller from alibaba site. The only problem is that it is nothing the same as my old controller. The wire color & number of the wires are not the same, the wire label is in chinese, although they try to translate it in english using the diagram, it is not the same and make it very complicated for me.

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The best teacher is experience.
Dive in!

you will learn loads just by trying to figure out how the thing works. Don't be afraid to take apart your motor controller and look at the parts inside. On balance, everything adds to what you know.

Excellent thread, love reading it!

Pyon said:

Excellent thread, love reading it!

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you are welcome!

EGod- incredibly informative write up, a veritable book on the topic... Recently found this site and thread as I'm considering custom building a stand up full suspension off-road scooter for gravel roads and trails. I have extensive experience with the mechanical side of such design processes but you've clarified motor selection and provided a wealth of controller info that I knew little about. Thanks.

Decades of serious cycling have led to some minor nerve damage so sitting on a bike seat is no longer a good idea. Stand up scoots are a fun alternative and similar to skiing, which I also enjoy. Would need to go electric with this one for the silent stealth operation. I've already built a few state of the art human powered kick scooters.

What happened to all the pics on your posts? All sadly unavailable...