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Here's a detailed explanation of how to get backup power from a Zero motorcycle. I've shown most of these pieces in other posts but here's everything you need to know in one place. There's a video that I posted on the Facebook Zero Motorcycles Owners Group that shows it all working, you can see it and download it here https://drive.google.com/file/d/1N4gv07_ggUlECXyOvBImH_AHT9HtKKzL/view?usp=sharing. Actually it shows several different things, I'll describe each one separately .

But first some reality checks. Electricity is dangerous. Don't mess with it if you don't know the basics and understand the risks. I know a lot and I still got some surprises in learning about this specialized application. Next, be aware of the limitations. There are only so many kW hours in the Zero batteries, it won't run your whole house for very long. And of course you can damage your batteries by discharging them too far. Maybe the BMS will prevent that, maybe not. And if you drain all the charge from your bike, you can't use it to go get gas for your generator to recharge it. I'm not going to cover charging here except to mention that of course solar or a generator can be used if the grid is down. But you can get power silently at night from your Zero, here's how.

First and foremost you need an inverter. Well actually you don't if you can use DC power. Regular light bulbs, heaters without fans, universal motors and many chargers will run on DC. The tricky part is that switching and protecting DC circuits is more difficult than AC because it will arc, a lot, watch this . So special breakers, switches and relays are needed for DC. With solar installations becoming common these parts are readily available, but they are not the same as those used for AC.

I bought this inverter https://www.ebay.com/itm/2500W-Off-Grid-Pure-Sine-Wave-Power-Inverter-Solar-inverter-CE-EMC-Certified-/232508158041
Credit to Doctorbass for finding it, the 90-120 volt DC input voltage range needed for Zero power is not common. Mine came direct from China. There was a 15% upcharge for the high voltage version but it was still under $300. But you need to specify the voltage and outlet type to get the right one. This thread has the discussion that inspired me to try it, which I did http://electricmotorcycleforum.com/boards/index.php?topic=7415.0. The Reliable Electric inverter works well, is inexpensive, was delivered quickly and does what they say it will.

The next hurdle is connecting to the bike or power packs. I'm doing both but I had to get to know the Anderson connectors first. These are used in the pack adapter and Y cable you can buy from Zero, but you will need to make your own connections to the bike and inverter. http://www.zeromotorcycles.com/shop/index.php?main_page=product_info&cPath=15_5&products_id=186&zenid=ebfqhfimtda5domiq436amllc0  http://www.zeromotorcycles.com/shop/index.php?main_page=product_info&cPath=15_5&products_id=196&zenid=ebfqhfimtda5domiq436amllc0 

The external charge port on the bike and the Y cable use the Anderson SBS 75X connector. The housing is https://www.mouser.com/search/ProductDetail.aspx?r=879-SBS75XBRN I used these pins for the main contacts https://www.mouser.com/search/ProductDetail.aspx?r=879-1339G3-BK These are for 10-12 gauge wire, heavy enough for short distance runs of the level of current my 2500W inverter can use. A larger inverter might need the 8ga or even 6ga pins. You might also need the smaller pins that are used in the Y cable for the enable signal. More about that later but essentially you will need to connect these if you want to get power from packs off the bike as the video shows. The males pin will send an enable to the pack https://www.mouser.com/search/ProductDetail.aspx?r=879-PM16P1620S30 I also use the female pins to receive the enable from external chargers https://www.mouser.com/search/ProductDetail.aspx?r=879-PM16S1620S32

The Anderson pins need to be crimped or soldered. They can be inserted without special tools. Removing the large pins can be done with a small screw driver, google it. But removing the enable pins is difficult and requires a special tool https://www.mouser.com/search/ProductDetail.aspx?r=879-PM1003G1 I crimp the large pins with a bench vise, crude but effective.

Once you are connected you might want to know how much power you are using and how much is left in the battery. EDIT I DO NOT RECOMMEND THIS METER!! NOT RELIABLE AT 116V details in post below. I like the DROK DC meter shown in the video. It is inexpensive, accurate and flexible. I made a neat package with the meter, connectors, a switch and battery that does everything I want without a messy tangle of wires. Pictures and schematic are attached. It measures everything, volts, amps, watts, watthours, time etc., in either direction, charge or discharge. There are two versions, a 30amp and a 100 amp current shunt. I bought both but ended up using the 100amp without the relay available here https://www.amazon.com/DROK-Multimeter-Charge-Discharge-Electricity-Overvoltage/dp/B01M5CWR2P/ref=sr_1_3?ie=UTF8&qid=1512684063&sr=8-3&keywords=drok+dc+multimeter The meter isn't essential but it is very convenient.

With inverter and connectors you can do what I show in the video. First, I connect the inverter to the bike external charge port directly. Turning the key on closes the contactor. Note that there must not be a load connected when the key is turned on. The bike will precharge before closing and that will fail if there is a load, so the inverter should be unloaded or off first. After the click, the inverter can be turned on and then loaded, by a heater in the video. The inverter recommends turning the load off before switching off the inverter, probably to prevent arcing. That is also good advice for the bike contactor, that is turn off the load, then the inverter and then the bike so that there is no current when the contactor opens.

At about 50 seconds the video shows the DC meter connected between the bike and the inverter with the heater load. The meter's current shunt can be connected in either direction and that affects the polarity. I have it so that discharge shows as negative current although DROK calls that CHG in red. At 1:05 the video shows the meter while charging with two DeltaQ's and a Y cable. That shows a positive current of 17 amps, 2kW, and DIS in green. I may decide to reverse the polarity to make better use of the battery capacity readings. It is all explained in this pdf https://images-na.ssl-images-amazon.com/images/I/C1KogaBOhLS.pdf

While connecting to the bike is the simplest way, it has drawbacks. Leaving the key on is the only way I know to close the contactor. If there is no rider input, the bike will open the contactor after one hour. So you burn headlights and have to keep it going by doing something at least every hour. This is an unsolved problem, unless you have the modular packs.

Next, the video shows how to use the packs off the bike with an inverter. You need an enable signal to get the pack to close the contactor. I discovered how to do that in this thread http://electricmotorcycleforum.com/boards/index.php?topic=7116.msg59032#msg59032 With a pack adapter the connection is simple as shown in the meter schematic. It is just a battery connected to a male pin on the SBS 75X in either the P1 or P2 position. This simulates the enable signal from an external charger. It is best done using a 10k resistor so that current is limited. I've seen the Trikester version on Burton's wiring diagram that uses a 100k resistor to the 100v to do this but I haven't tried that. The voltage is not critical, I've used two or three AAA batteries to get 3-4.5 volts and am now using a 3.7v lithium coin battery in the meter package that I built. I have a switch so that the enable signal can pass through from a charger or come from the 10k resistor battery circuit as needed for discharging.

There are some quirks with the enable logic with packs off the bike. Same as when connecting to the bike, it is best to have no load current when closing or opening the contactor. However, if the pack is not fully charged it expects current flow soon after closing the contactor. If no load is turned on, the contactor will open after a short time. So in the video, I switch on the battery enable signal and then turn on the inverter and heater, that keeps the contactor closed. A fully charged pack will stay closed with no load and removing the load is OK once the contactor has decided to stay closed.

That ends the video and concludes my explanation of how to get power from your Zero. You have to give that power back of course, and then you have a Tesla wall, energy storage for later use. There are many ways to do this but I chose a simple and relatively inexpensive approach. I hope this information is useful, but of course I make no guarantees, it might not work for you, and lots of things can go very wrong!

Here's a crazy idea that might be of some interest. My DC/DC convertor failed recently and I noticed that everything else worked fine without it. No lights of course, and the ABS was disabled (as usual for my off road use). There was only one flaw, no brake light triggered regen. That was really annoying. I had to quickly relearn how to use the rear brake, serious business on steep downhill trails. Anyway, i wondered if it would be possible to get regen without any 12 volts at all. It is, here's how, I'm pretty sure, use at your own risk. I may do this this myself, undecided so far.

How to stop charging below 100%?

Assuming you don't want to top up your bike and would rather charge it to some lower SOC, what can you do?

There are some manual methods. You can watch the dash SOC indicator during charging and disconnect anytime. You can ride until you reach some desired charge level and then don't charge. You can calculate the time it will take to reach a desired charge level, go away and come back to disconnect when the time is up. There are obvious problems with all of these choices.

How can this be done automatically? I will attempt to explore all of the possibilities and maybe I'll do something myself. Others are welcome to use my ideas. Here goes:

First there are a many ways to charge so that creates multiple solutions. In any case charging can be stopped either by disconnecting the AC to the charger or by controlling the charge enable logic. Deciding when to stop charging can be based on time, battery voltage, or some other SOC reading if available.

The simplest solution appears to be a settable timer on the AC to the charger. A calculation based on the current SOC, charging rate, and desired SOC is needed. That's a fairly easy web page to create, maybe I'll do that. Given the time it will take to reach the desired SoC, you set the timer and done. Complications include what type of AC connection is being used, and the accuracy of the charge prediction given variables like temperature, line voltage, pack condition etc. Huge advantage of this approach is it uses off the shelf components, no design needed, no warranty worries.

An existing, smart external charger with user input to select a desired stopping point would be great, but this choice doesn't seem to be available. Adding or modifying charger firmware requires proprietary knowledge so it probably isn't feasible. So it seems that some custom design may be required if the timer method isn't attractive.

Next up the ladder of complexity and design effort would be a pack voltage sensing AC power control device. This could be set to stop charging at some desired level by switching off the AC to the charger at a desired cutoff voltage. There are a few drawbacks to this approach. First it requires an AC power switching device rather than using existing contactors. Next it depends on a voltage reading that is going to be different than the final SOC voltage after the charging current stops. Some higher charge levels may not be settable because the cutoff voltage will be higher than the fully charged voltage. However this approach could be adapted to any bike and charger configuration. Voltage for sensing is available at the external charge connection and AC control is external to the bike. User input is simply what voltage to stop charging and that could include don't stop until the bike stops at 100% SOC.

It is possible to control the pack contactor using the enable line. Again pack voltage sensing could be used, or possibly some other SOC value obtained from the bike. In the case of external chargers the enable line is accessible and used in the connection to the bike. This approach looks pretty simple once the hurdle of an arduino type project is undertaken. The processor would have three inputs, user setting for the desired charge, voltage of the pack, and the enable line from the charger. The only required output is the enable signal to the bike.  A pair of Anderson SBS 75X connectors puts the charge control device in series between the external charger and the bike. Power for the arduino could be from a battery so connection is simple. This idea might be a winner except for the programming piece.

Controlling the on board charger enable logic gets into some trouble with hardware, by modifying the bike wiring, or software, since communication with the MBB, BMS, CAN bus and charger gets complicated, bike model specific and is probably not feasible for development except by Zero. So the only practical way for riders to control on board charging seems to be AC power switching as already discussed.

That's it as far as I can come up with on a Sunday morning. Did I miss anything? Is this worth pursuing?

I'm fighting a war against isolation warnings on my FX. I saw this with a cable connection this morning "CHASSIS ISOLATION DANGER: 2 KOhms to cell 2" The log file has this instead "08147     06/29/2017 08:28:51   Low Chassis Isolation      2 KOhms to cell 2"  Interesting how different the presentation is for the same event. Anyway, I've done a lot of work trying to make this better, even though it hasn't affected the bikes performance in any way. I don't like seeing the red light flicker while I'm on the trail, and maybe it really is dangerous. The readings change rapidly, from 2K to 78K a few minutes later. So I'm not sure how real the problem is. But I've attacked the chassis wiring, removed all of the side panels, cleaned and replaced dielectric grease on every orange wrapped connector, put it all back together and it works (whew!) but when I hooked up the serial cable to see improvement, I got DANGER instead.

I've swapped through all four packs, one at a time and in both positions, with no significant differences. Plenty of warnings still with each. So right now my packs are in the sun with the plugs removed to hopefully dry out. I'd do more but I have almost four years of pack warranty to lose. I'm going to try to measure resistance from 100v connections to the frame with no pack. I don't know if the 12V wiring is also checked for isolation. I decided to start this war when the DC-DC converter didn't turn off. That connector is not sealed and has the enable line adjacent to the +100V pin so it isn't surprising that the mud I found there was causing trouble. This is West Virginia coal country mud, probably more conductive than most.

Here's a picture of the battlefield, I already put it in the wiki in the Routing section. I note that the component locations are very different on the FX than other models. Any advice is welcome.