Gas tank, side panels, ammeter, start switch


Ready to ride?  Not quite, but I’ve made some nifty side panels, cut the bottom of the gas tank out, semi-installed an ammeter, and have the starter relay wired up with a new bar-mounted switch.

I had a latching relay on order last post.  It arrived, and works just fine, but when I looked at the wiring diagram for the relay I could not for the life of me figure out how to reset the relay without the use of multiple switches.  The problem was that in order to reset the relay I had to be able to apply a pulse of electricity with a reverse polarity.  If you’ve ever wired a switch imagine rewiring it so that you can supply both positive and negative from each side.  Once you start thinking about it your conclusion will be the same as mine which was “fuck that.”  I think they make these to receive the reset pulse from a different power source.  Since the ground is always ground, it would require switches on the ground and the positive in order to reverse the polarity.  Fuck all that.  They do make latching relays that have separate terminals for the reset pulse, but I’m a bit tired of ordering relays so I just stuck a simple switch on the bars, and used a normal, high voltage relay that I already had.

Relay is on the left, the flasher relay is the orange one.

Closeup of a side panel that I cut out of some 22ga steel.  They looked stupid as big plain solid sheets of steel so I snazzed them up with the vents.

Here’s the little starter switch I added.  I thought the led might be helpful as the motorcycle is pretty much silent until it gets moving.  You do hear a “click” when the relay activates the main contactor, but that’s about it.


Here’s the ammeter that I stuck where the old filler cap was.  It should tell me the current draw as I’m using it.  Not super-necessary since I’ll have a cycle analyst that should tell me the same thing.  I just thought it might be something neat to fill the hole with. (that’s what she said?)

If I had the batteries all done it’d be rideable right now.  So far I’ve processed about 560 cells.  Of which, about 150ish were fried, and about 50 of my ‘B’ grade cells have been set aside to use as a 12v battery to run everything but the motor.  I’ve got about 360 ready to be assembled into packs, and have more coming in the mail in a few days.  I need 600 for the main pack.  I’ve been processing these during all waking hours for about 2.5 months.  It’s a slow process, but the batteries are a huge expense to buy new.  600 new 2600mah 18650s can be purchased for about $3000 if you can get them for $5 each.  If you get them from used laptop batteries bought via ebay you can get 600 for about $750 to $800 depending on your luck.  The downside is it takes 3 or 4 months to test and sort the 800 you need to get 600 good ones.  Most of that time doesn’t require you to do much.  You just have to keep cycling batteries between charging and testing.

This video outlines the process:


Got the 12 volt system mostly wired.

I nearly have all the 12v stuff done.  I’m really just waiting on a relay that I want to use to turn on the 72 volt contactor.  It’s a special relay called a “latching relay” that uses permanent magnets to keep the switch connected after an intermittent pulse of power is applied.  This way I can use the start button to turn the main contactor on.  If I used a regular relay I’d need a switch.  There is no kill switch on these aftermarket handlebar switches or I’dve just used that.

Relays and contactors are simply switches.  Switches that utilize electromagnets to close a circuit.  The purpose of the smaller, latching relay is to allow normal 12volt switches and wires to power its magnetic coil, closing the circuit that I have connected to the 72volt main contactor.  So a little switch is turning on a big switch, which allows higher voltage and amperage to power the motor.  The 72 volt switches and cables need to carry 72volt, and 200amps continuously, which would totally fry/melt most 12 volt components which usually carry less than 15 amps @12volts.

The 12 volt system is most of the normal motorcycle wiring…horn, headlight, brake light, turn signals, keyswitch, etc.  It sounds simpler than it is though.  For instance, the two left and two right turn signals are switched by a handlebar switch that gets its power delivered through a flasher relay (which basically just turns the power on and off to makes the lights blink).  Simple right?  Right.  Then you have to also connect the four turn signals to the hazard switch.  You can never feed one side off the other, or all blinkies will flash whether you switch left or right.  Then the two rear blinkies need to also be connected to the brake light, which is connected to the front brake lever as well as the rear brake pedal.  Then all the lights also have a running light feed, and maybe some led indicators that tell you if you forgot to turn your blinkies off or if you’re driving around with your high beam on.  Then I’ve got all of this stuff running through a little fuse box, and a main light switch, plus a keyswitch on the bars.  Needless to say it’s a lot of fucking wires, switches, connectors, and soldering.

That, and I’ve not used anything from the original bike.  Well I did salvage the original rear brake switch, which I mounted in a different position.  But all the wires, switches, and connectors are new.


Cut down the brake light, and welded a bracket to mount the license plate in a way that doesn’t mess up my pretty fender.


Headlight, running, and blinker all on at the same time:


Little key switch in a mount I made from a couple of pieces of bar stock welded together.  I decided not to run the spedometer/odometer.  I’ll be using a cycle analyst anyway which makes that blob redundant.:

I still would like to wire some led “dash” indicators, and I need a little light shining on the plate to meet legal requirements.

Next I need to start getting serious about the battery packs…