Wheels Spinning! With caveats...

I have 'succeeded' on the installation of my new 120V upgrade to the Honda! Almost...

Yesterday, I got the high-current wiring relocated and connected between the controller, the contactor, and the motor. Today I rewired just about 100% of the low-current wiring inside the panel box that provides power to the contactor and controller.

Then I hit the snag... I reconnected the battery pack, turned the system on, and all of a sudden... Nothing Happened. There was no error code flashing on the controller, just a steady green light. There was no satisfying "chunk" of the contactor closing. There was no spinning of the wheels when the throttle was advanced. There was nothing.

Hmmm.

I did a little debugging, and decided that for some reason, the controller is not pulling the contactor to ground. So as a test, I bypassed the controller and wired the low side of the contactor directly to ground. And that worked. Then the contactor went chunk, and the wheels spun when the throttle was pressed.

OK... so I just have to figure out what's going on that the controller is not controlling the contactor as desired. A question for the community, or the manufacturer, next chance I get.

Here's the engine bay of the nearly-completed 120V upgrade. White box tucked up in the grill is one of the heated, insulated battery boxes. Toward the rear, driver's side is the new controller and converted throttle. And to the passenger side of the controller is the panel box where many of the goodies hide such as the contactor, the fuse, the kill switch, the current shunt, the precharge resistor, etc. The panel box is kind of hiding behind the reflector of my shop light, sorry about that.

Looking inside the panel box. You can't really see much of the high-current wiring in this pic, except the 400-amp fuse (round white thing) and the front of the contactor (black box above the round white thing). The two thick red cables running in front of the panel box are the 2 wires from the controller to the motor, and the black cable cutting the lower right corner of the picture is the "most negative" cable in the car, returning the motor current from the controller to the low side of the battery pack.

All of the low-current wiring (skinny red, black, and green wires inside the panel box) is what I was working on today. The main issue was that the old controller used 72V pack voltage to run it, but the new controller does not use the 120V pack voltage, it uses 12V from the auxiliary power system to run it. In the process of rewiring that, I decided to change a couple other things, too. The relay that used to be pulled by the ignition switch to feed 72V to the controller, I am now using to feed 12V from the main fuse box to the controller, the contactor, and the power brake pump, instead of feeding all those components straight through the ignition switch. It's a cleaner power source... I measured 13.3V from the ignition switch, and 13.5V straight off the main fuse box.

A better view of the 120V controller (Kelly KDH14500B) and the rewired throttle box.

PB-6 Converted to 0-5V

For the Kelly KDHB series controllers, they only accept 0-5V throttle input. The Honda had a PB-6 two-wire 0-5Kohm throttle on it. So tonight, I converted it. Hooked up 5V to "the other lead" on the potentiometer, and also took the opportunity to wire up the throttle switch, which wasn't connected previously.

Back Side.

Front Side, with Kelly-provided "J2" connector and wiring harness.

New 120V Controller

I'm working on installing the 120V controller yesterday and today. It's a Kelly KDH14500B. Cut a new plate to fit under it, and mounted it on the plate with silicone heat sink compound. Boy, that stuff makes a mess, when you're trying to cover a 6" x 11" area!

Here's the new controller, mounted in place but not wired in yet:

Insulated Rear Battery Box

Today I built the battery box for the 4 Discover EV31A-A batteries in the far rear of the Honda. From start to finish, it took me about 9 hours, not including breaks! My wife was helping me for about the last 3 hours, too. The tasks included: Unwiring the 4 batteries and removing them from the car. Cutting a 1/2" styrofoam sheet to go under the 4 batteries. Wiring up the 4 heater pads and the thermostat. Mounting the heater pads in the car. Replacing the 4 batteries. Cutting and fitting the styrofoam walls of the box. Fitting a lid. Wiring the batteries all back up. Mounting the thermostat. Cleaning up.

Now all of my battery racks are running at a nice toasty 90'F!

Some pics:

The box, about 1/2 finished, putting together an inside corner.

The corner after it's been slid into place

Buttoned up with the cover.

[Yes, I remembered to get the scissors out! :-)]

The thermostat hides under the block sticking out. Hot water heaters place their thermostats under the insulation, so that the entire body of the thermostat heats to temperature. I mounted the thermostats on the batteries the same way, surrounded and covered by insulation.

Insulated Front Battery Box

The last couple weekends, I've been working on building insulated, heated battery boxes.

Here are a couple pictures of the battery box that has the two batteries just behind the front grill of the car.

The completed box.

The thermostat on the rear of the box.

Here is the group of 4 Farnham battery heater pads, mounted on a sheet of styrofoam, ready to be placed underneath the four batteries I installed Oct. 31st (see previous post).

New batteries & battery heater pad

Today I performed a temporary install of the 4 new batteries I've purchased for the Honda. These are in addition to the 6 it already has, thus making it a 120V system with ~12kWh pack (2o hr. rate). These four batteries plus the other two under the hood will be charged by two Dual Pro Recreational Series 3-Bank 6-Amp chargers. Each charger has 3 independent, isolated, microprocessor-controlled chargers capable of pushing 6 amps, which may be used in series or in parallel with each other. Here's a picture of the batteries wired up into a temporary 48V bank, with the Dual Pro chargers sitting next to them.

Also, I found out about a very economical way to control the temperature of batteries being warmed by battery heater pads: Water heater thermostats. These thermostats switch 120V AC, and handle the wattage of normal hot water tank heating coils. Perfect for the battery heater pads I've bought, which don't come anywhere close to the wattage of a hot water tank. And they cost less than $10 each, so you can afford to put one on each bank of batteries you'll be heating. That's important because different banks will have different thermal properties depending on their isolation from the outside environment. Here's a picture of a water heater thermostat I bought at Lowes, sitting on top of a Farnam battery heater pad I bought from KTA Services. The thermostat can control in a temperature range of 90'F - 150'F. Which is fine for lead acid batteries, since you probably want them warmed to about 100-120'F for best performance.

One thing Dave Cloud warned me about with the hot water tank thermostats, is to do one's best to isolate the thermostat from any possible gas the batteries might vent. This is due to the possibility that the contacts inside the thermostat could spark when making/breaking the circuit, which could ignite a concentration of hydrogen gas. While I assume this is more of a concern for flooded batteries than the AGMs I'm using, it's a valid point and one I will have to consider.

New 4-Bank 10-Amp charger

Today I installed a new charger on the 4 batteries in the rear of the Honda. After looking a long time, I found a really good deal at ChargingChargers.com on the Dual Pro Sportsman SS4. This is a 4-bank, isolated, microprocessor-controlled 12-48V charger, which may be used as a single 12V-40A unit, 24V-20A, or 48V-10A, and so forth. It has a 3 year warranty. According to the box, there are 750,000 Dual Pro units in the field, and they tout being green by virtue of being 100% repairable, NOT disposable. Made in America.

I installed this charger to replace the four Soneil 1206S chargers that had been on these batteries before, two of which failed this summer during the hot weather.