Charging, Adapters, and RV parks

by Ben N on August 2, 2015

This weekend, I had a chance to keep working on battery charging for the Vectrix and start working on adapters as well.

To start with, I assembled the second set of three Mean Well power supplies in series to create another charger. I set all three to a matching maximum current and even 50V output. Then I crimped together black to red, black to red, in series. I connected the most negative and most positive wires to an Anderson 50A and heat-shrinked all connections.

IMG_4541With that, I set both of the chargers on the seat of the cycle and plugged them in to the 125-amp Anderson disconnect to connect them to the main battery pack. On the AC side, I plugged both chargers in to an extension cord to a 20-amp circuit. Besides that, I ran my stock charger into an extension cord to the other circuit available in my garage.

At this point, I had all three chargers going and was drawing up to as high as 4200 watts. I took a few photos with the thermal camera. Both of the Mean Well power supply chargers do get fairly warm. Powering at 120V, it’s a fair number of amps, producing some heat at the electrical connections.

Next, I wondered how things would run at 240V. All three chargers can run on either 120 OR 240 volts. Either way is fine, and they produce the same number of watts, no matter which voltage. The one difference is that at 240V, it’s half as much current, which means half as much heat, and less worries about using thicker wires to carry that current.

IMG_4549IMG_4559I already built a J1772 adapter to convert from EVSE to a standard electric outlet. Just recently, I purchased a pre-wired G.E. WattStation J1772 home charger. I plugged my adapter box into the EVSE and a short extension cord with a built-in three-way in to that. I now had three outlets with 240V power. I plugged all three chargers in to that. It worked great! Not only could I run all three chargers on one plug, but the connections were also considerably cooler at 240V than at 120v!

I let the cycle charge, monitoring the Cell-Log to check individual cell voltage, for a little over two hours, filling the pack with nearly 40 AH of juice. That same charge normally would have taken 4.5 hours.

So, I’m off to a good start, I can now charge twice as fast as I could with my stock charger. PLUS, I can charge at public EVSE.

I also want to be able to charge at state parks and RV parks. Those typically have a NEMA 14-50 jack, which provides power at 240V at up to 50 amps (which is a tremendous amount of power.) I stopped at the electric department of the home improvement store and bought a 15-50 plug, some 3/4″ rubber grommets, four 15 amp female extension cord ends, and several feet of 14 gauge three conductor cable, sold as replacement power tool cord.

Inside the 14-50 plug, there are four connectors – two hots, a neutral, and a ground. I cut the cord to four pieces, threaded them through a grommet, and stripped the jacket and then the wires inside. On all four cables, I twisted together the green ground wires and then tightened them under the screw for the ground pin.

Likewise all the black wires were twisted together and tightened under the screw for the Hot terminal on the Nema 14-50.

For the white wire, I did something different. Normally, for a typical 120V electric outlet, the white wire is neutral. There’s 120V difference between the black and the white, the hot and the neutral. For a 240V connection the other wire goes to the OTHER hot. (Normally, this would be a red wire.) So, I twisted together three of the white wires and screwed them down under the other Hot terminal. Only the one other white wire went to the neutral connection. That would be the 120V jack.


After double-checking all the connections, and testing them with the continuity feature on my multi-meter, I closed up the Nema 15-50 plug and screwed the cover in place.

Today, I took the family over to visit friends at a beach at a state park. The park also has a camp-ground, including electric sites, so I brought along the power adapter and my multimeter. (I didn’t have the cycle there. Hard to carry three people, a cooler, a solar over, etc. all at once on the Vectrix…)
I walked over to an empty electric camp site and tested it out. I plugged in the adapter and checked the voltage output of all four plugs. Sure enough, 240V coming out of three of them, and 120V out of the fourth. I even made sure to color code the plugs to avoid accidental confusion. Always a good feeling when I build something and it neither trips a breaker nor bursts into flames. IMG_4568

Having four plugs will let me quickly charge the cycle and still have a spare plug for charging a video camera or other equipment that normally runs on a standard 120V outlet.

So far, things are looking good. I’ll have to figure out exactly where I want to mount the Mean Well chargers onto the frame of the cycle. I may even want to bolt them to heat-sinks or an aluminum plate. Next, I need to start doing some range-testing. Time to figure out how far I can reasonably ride on a single charge when charging to a little higher voltage. After that, it will be time to work on aerodynamics, but that’s time for a different blog!

Till next time, stay charged up!



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Loop the Lake: Day 1
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