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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: Keith on December 08, 2017, 06:29:19 AM

Title: Backup Power from Zero batteries - HOW TO
Post by: Keith on December 08, 2017, 06:29:19 AM
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 https://www.youtube.com/watch?v=Zez2r1RPpWY. 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!
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on December 08, 2017, 06:33:01 AM
A few more pictures of the meter package. It made me very happy to figure out how to do this in a neat unit rather than a kludge of dangling wires. It's a very handy way to see what's happening. And it can be wireless so the meter can remote from the power and inverter.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on December 09, 2017, 05:22:22 AM
 :( I'm not so happy with the DROK meter now, just blew up another one. It sometimes doesn't like sudden applied voltage, like pack contactor closing with no load connected or plugging by itself into aux port while contactor is closed. Bang, spark, smoke, dead. Not sure what I'll do about it...

WARNING DON'T BUY THE DROK METER - EE explanation follows (I'm buying one more, see later posts)

Also sold by Vanjing, this meter has great features and is really cheap but it blows up at the Zero battery full SOC voltage and I know why. There is a work around if you really want the features, but the price is more than doubled.  It can be used if you choose the 3W jumper setting and use an external power supply, either a 10-30V wall wart or a DC-DC converter like this one http://www.mouser.com/ds/2/75/SPEC-ECLB40W-110-V11-1114358.pdf User manual here explains hookup with external supply ("three wire") but doesn't say why you should use it https://images-na.ssl-images-amazon.com/images/I/C1KogaBOhLS.pdf

The meter has a linear voltage regulator to reduce the 120V down to 10-30V for the 5V convertor it uses, but that is the weak link. I've had two of these self destruct, in the same way, with fully charged pack voltage suddenly applied. I'm pretty sure the MJE340 transistor goes into second breakdown if the applied voltage is high and the filter capacitor is fully discharged. It might survive that a few times but then it won't and many components go up in smoke. If the meter is connected to the bike with key off, the precharge brings it up slowly and that should be fine. But closing the contactor off bike or connecting to the bike with the contactor already closed: BANG, dead meter. So don't use it, or use it only with an external supply. Too bad, it really is a nice meter...
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on December 09, 2017, 06:53:32 PM
Quote
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.

Looking at the problem of closing the contactor with packs on the bike (keeping it closed while stealing power) I have a new finding. The enable line used by the pack adapter to connect the external charger is pin three of the pack. That pin is NOT CONNECTED on the bike. So there is a special pin on the pack just for the no CAN bus charging enable signal that I hacked. Wonder if that pin exists on the non modular bikes. Also wonder if you connect a 10k 5V pull up to it with the packs in the bike would that work?
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on December 12, 2017, 06:53:55 PM
I am buying another DC power meter, this time I won't blow it up!  :P https://www.amazon.com/review/ROJAZVXMUEDBC/ref=pe_1098610_137716200_cm_rv_eml_rv0_rv I'm going to use a nice little DC-DC converter with it so it runs cool and stays happy. There aren't many converters for the Zero voltage range but this one is perfect. https://www.mouser.com/search/ProductDetail.aspx?r=418-EC6AW-110S12 Stay tuned, I'm going to use this meter as a charge controller, you can set the stop voltage and control the external charger with a very simple setup.
Title: Re: Backup Power from Zero batteries - HOW TO - NEW INFO, CAUTION
Post by: Keith on December 20, 2017, 10:36:29 PM
IMPORTANT ADVICE - MUST READ IF YOU ARE GOING TO DO THIS
I've learned that the nice inverter I have includes a VERY LARGE input capacitor, about 2.5 millifarads. That stores a lot of energy (17 joules) and it means you will probably damage your contactor if you don't take a few extra steps. The inrush current if you close the contactor with a large capacitor load is limited only by the wire and ESR (probably many hundreds of amps), it will burn the contacts that create the circuit when they close. This damage can be prevented with a simple precharge circuit and some care in sequence. I'm using a 4.7k 5W resistor. That part can handle the full pack voltage indefinitely. It gets only slightly warm when used in series with the inverter input to charge the capacitor. About one minute after closing the contactor, the inverter will be almost fully charged through the resistor (time constant is 12 seconds) and you can then short the precharge resistor with a switch. I'm using a 20A light switch for that. The inverter can then deliver power to the AC load. Your contactor will thank you!

It's also recommended NOT to use the inverter power switch or the contactor to turn OFF the power. Instead, turn off the AC load, then turn off the inverter, then open the contactor. Turning off high DC current causes arcing as I mentioned in the first post. Using the right sequence to power down avoids that. So precharge, then close contactor and then connect load to power up. Disconnect AC first to power down. I'll make a circuit drawing and maybe a fun video with some sparks later.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: MrDude_1 on December 20, 2017, 11:58:08 PM
Sounds like you enjoy playing with the same fun stuff I do.
What I would add to this is a simple MOSFET controlled switch so that the inverter (or other load) can precharge safely then turn on automatically.
something like this:
https://endless-sphere.com/forums/viewtopic.php?f=3&t=40142&start=100

The more foolproof you can make it, the better... because even the best of us make mistakes in connection order.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on December 21, 2017, 04:10:44 AM
Mistakes? Not me, I only uncover design weaknesses that are mistakes made by others!  ;D And those mistakes blow up meters, make big sparks, pop fuses and do worse things that I won't mention.  :-[ That precharge circuit is interesting, I'll look into doing something similar with my setup, foolproof is best. Zero has done pretty well with achieving that but I've found some ways to get around their efforts. Deliberately of course.  ::)
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: MrDude_1 on December 22, 2017, 06:42:49 PM
Mistakes? Not me, I only uncover design weaknesses that are mistakes made by others!  ;D And those mistakes blow up meters, make big sparks, pop fuses and do worse things that I won't mention.  :-[ That precharge circuit is interesting, I'll look into doing something similar with my setup, foolproof is best. Zero has done pretty well with achieving that but I've found some ways to get around their efforts. Deliberately of course.  ::)

If you (or someone here) has a pinout of that module, it would be cool to see if it already had a precharge output you could use.... then just connect that via mosfet/resistor, wait until the voltage equalizes, then turn the contactor on. Even that is not foolproof is a load is placed on it while precharging.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on December 22, 2017, 07:36:06 PM
That's a really interesting idea, it pretty much has to be that the bike precharge is done by circuitry in the modular pack. I've found that the Sevcon in my FX has about the same capacitance as my inverter. I measure 3mF across the aux connector so the amount of precharge needed by the bike is almost the same. Whether the MBB is or needs to be involved is the question. My wiring diagram has many clues, for example the brown and brown/white wires labeled system on in and out are likely involved but who knows who's in charge of those signals? The MBB watches the key switch so it wakes up the system, but the pack may only need a simple command to do the work. Not likely that CAN bus gets involved with basic startup. BMS logs clearly show the management of precharge and contactor operation. I was about to order parts to build my version of fechter's nice circuit, now I may need to reconsider...

https://zeromanual.com/index.php/Unofficial_Service_Manual#X-Platform_Schematic
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on December 31, 2017, 03:07:02 AM
I tried but could not hack the System On logic of the pack. Logic high on 'System On In' does pass through to 'System On Out' but the serial BMS reports system off even if the contactor is closed. Might be a handshake with the MBB, the bike on state of 'System On In' is low while 'System On Out' is high. CAN bus? Or just a handshake, maybe I'll borrow a scope. A simple jumper for the loop back leaves the second pack pins accessible to probes.

I'm working on a really nice precharge circuit, details soon, if/when it is working. Meanwhile i have a resistor and a light switch. I have one real world example of what I might use the inverter for if the power goes out. I have a wood pellet stove that makes great heat for cheap but it has a blower so it needs a little power. I could run it for days with my packs. It would be crazy to run a 5kW gas generator just for that.

I have a really nice new package for my DC meter now, much cleaner than the previous version. I'm waiting for a DC converter that is back ordered to finish it but it is working with wall wart power now. I'll post more pictures and applications for the meter when it is finished but it's really cool now that I know how NOT to blow it up. I'm going to use it to control my chargers as well as for discharge control.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on January 11, 2018, 11:10:12 PM
I put my inrush control design on endless-sphere if anyone is curious and technical. I'll post it here after it is built and tested but it looks very promising. I really hope people are paying attention, inrush current will damage your contactor, it takes more than an enable signal to do this right.

https://endless-sphere.com/forums/viewtopic.php?f=3&t=40142&p=1350217#p1350217
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Shadow on January 12, 2018, 12:29:35 PM
"it takes more than an enable signal to do this right."
Does this help at all for better safety to connect and disconnect another Zero bike's onboard charger input to the DC system voltage of a "power donor" bike?
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on January 12, 2018, 05:49:51 PM
I don't think so. Any connection or disconnection should be done with power off and contactors open. If a charger is designed to work from DC input there shouldn't be any inrush, the charger should control that when power comes on during the bike precharge.

Title: Re: Backup Power from Zero batteries - HOW TO
Post by: valnar on August 09, 2019, 03:35:33 AM
I was just looking at buying a portable generator for home emergencies.  That took me to Generac, which then took me to inverter generators, the Goalzero Yeti's and back to here.

If using your Zero motorcycle as an emergency power source was easily possible, that would be a killer feature.  The highest Yeti is only 1.2kWh.
 Most of us keep our Zeros at 60%+ charge anyway.  Even if you didn't want to do the build from Keith, could you utilize the electronics from an existing Yeti for extra power in some way?  I love the possibilities.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on August 09, 2019, 04:46:00 AM
I fried my 2.5kW inverter and I have not found a reasonably priced replacement. Inverters that can handle the full Zero battery voltage are rare.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: talon on June 24, 2021, 12:26:47 PM
Keith, sorry for the bump but server grade uninterruptible power supplies make very economical, reliable inverters. They almost always are scalable battery-wise, <$400 because the batteries have died, and made to work in hot humid climates (no ac when the power is out!)

I am doing the exact same project with a standalone 2012 ZF9 battery. My discovery seems to be that ALL the precharge circuitry is either done by the MBB/CCU/or the motor controller. The contactors' coil wires are directly wired to a large connector on the rear of the battery (and seemingly not to the BMS at all), so it's very manual and I may need a precharge circuit. I'm curious if your modular FX batteries are this way or if the BMS gained that circuitry when they went modular/post 2012.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on June 24, 2021, 06:56:25 PM
Good luck! Be careful about the inverter DC input voltage, scalable might be batteries in parallel not series. Server grade is good stuff but transistor breakdown voltage is not forgiving regardless. Precharge is essential whenever a battery and capacitor are connected. It can be done with a resistor, I used 4.7k 5W if memory serves. The 16 FX BMS just checks the voltages across the contactor, won't close it unless precharged. 
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: talon on June 24, 2021, 09:28:24 PM
What I meant by scalable is that there is literally a parallel connection for "unlimited" additional batteries at the rear of the unit. Due to the strange voltage of my lithium pack (18S--65.7Vnom) I went with a 72V (5B or 30S) lead acid UPS that has plenty of headroom on the max voltage specs. It has an adjustable low-voltage cutoff and a max range of at least 80Vdc. I could have gone with a rare 60V (4B or 24S) lead-acid UPS and it likely would have been fine being well outside it's upper voltage range, but I wanted to be within spec of the UPS.

I'm assuming precharge is only to protect the contactor and nothing else? As much as I hate it, I'm thinking of using a board with 3 switches and a couple sacrificial relays. I even have a spare contactor from a larger, dead Zero pack I could use. I'm thinking the process goes like this:  feed load with resistive line (1Amp fused) to charge caps, next additionally connect low-current (30A fused) carrying line with no added resistance, then close contactor. Then disconnect resistive and low-current lines and increase load. Do you believe the contactors are designed to break full load current if the battery is being overcharged or overdischarged with your FX?
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: DonTom on June 24, 2021, 10:57:03 PM
Wire round resistors?  What frequency AC?  There will be less current with AC because of the inductance of wire-wound resistors. .  To do a fair comparison, you need to have an AC ammeter in series.


-Don-  Reno, NV
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on June 25, 2021, 04:54:58 AM
Your relay scheme will probably work fine. The contactors can handle a lot of inrush current, but without precharge the initial current is theoretically infinite, limited in reality by the wire, inductance and capacitor imperfection. The Zero will close the contactor with a pretty large voltage difference, including between two modular packs which then equalize instantly.  So precharge doesn't need to be perfect, but it needs to be.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: talon on June 25, 2021, 08:35:00 AM
All voltages listed are DC. I'm not doing anything with the pure sine wave output of the UPS inverter. Trying to figure out the DC side of things from the battery pack's cells through the contactor to the UPS DC input. (https://i.ibb.co/0snCqQK/temp.jpg) (https://ibb.co/0snCqQK)
Would something like this work for basic precharge function (closing PRE, then QUIQ, then CONT, and then disconnecting QUIQ and PRE)? Forgive me, I have no experience drawing circuit diagrams and am aware that this has backfeeding issues that would drain the caps, feed the relays, and has garbage component values.

Part of me is considering leaving the resistive wire attached full time, except when I need to completely manually disconnect the load to save the <30W or so that can be drawn at UPS idle if its computer wakes up. It's so weird that the BMS on this 2012 ZF9 pack seemingly has no control of overdischarge and overcharging! That's a lot of faith by design in the (albeit well-made) Delta Quiq chargers! Even the Quiq charge and onboard charge ports are simply fused (30A) and go straight to the positive bus bar (no contactor)! I suppose the BMS could "beg" the MBB/CCU/Sevcon to open the contactor in an emergency or send a disable signal to the Quiq, but having that functionality external to the battery makes no sense to me. Dealing with a contactor raw is nice in some ways but makes me a little uneasy that I'M responsible for all the protections, and I currently have no way to verify balance/imbalance except the light signal.

I might add an extra high rupture capacity fuse or two to this everywhere I make a major connection.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Keith on June 25, 2021, 07:22:35 PM
Chargers don't rely on the contactor. They supply a current that is reduced when the battery voltage approaches full charge, becoming zero when it does. Contactor can stay closed without worry during charging (with a smart charger like the DeltaQ).

If the resistor is fairly large, the UPS won't be able to run because its current draw will drop the voltage below its minimum. So leaving it connected may be ok.

Too many problems with your diagram to even begin, but I get the idea.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: talon on June 26, 2021, 10:15:06 AM
I just meant in terms of tolerance to a faulty charger (say, if it somehow was set to overcharge or had an internal short draining the battery below cutoff)--not to break charging regularly. I believe all later zeros can't charge when the contactor is open so this just seems like a very strange design quirk for this year. Honestly it makes the MBB really part of the BMS system rather than keeping all protection (over temp/voltage/current, balance, low voltage, isolation) "in house" to the battery. But that is looking at these components with a perspective as if they were designed to work independently off-bike (not as part of the bike's system), which AFAIK isn't true until the 2015 powertrains were developed to be sold separately.

Yes, the diagram is embarrassing to me and was done in crazy haste as I've been travelling a lot and haven't had the time. I did read through yours and Farfle's posts on precharge circuits and theory on endless-sphere to see what I could grasp and if I was missing any important considerations. Posted here as a sanity check. Thank you for your work and for sharing your time and research with the community.

Title: Re: Backup Power from Zero batteries - HOW TO
Post by: ieism on July 18, 2021, 06:13:01 PM
This is a neat idea, but i'm not skilled or smart enought to pull that off.

I have a 2kw battery in my 4x4 with solar and a few bits and bobs running more or less full time. When I go camping, I sometimes run out of battery, but there is not much more room to put leisure batteries and they are expensive.

The Zero FXS comes on trips, that's 7kw of power just sitting there and I wish I could use that. Could I get a 12v out from the bike easily and run my 12v car stuff from the bike in case I ever need it. The batteries on the car are wires with Anderson connectors, my thought was to just wire a plug form the bikes 12v directly to the 12v system on the car but I'm assuming I'd have to disconnect my solar to prevent it putting in power somehow.

Is there a better safe and simple way. I can solder and understand simple 12v stuff, but I'm not that good with the rest of the thongs mentioned above.
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Richard230 on July 18, 2021, 07:05:19 PM
This is a neat idea, but i'm not skilled or smart enought to pull that off.

I have a 2kw battery in my 4x4 with solar and a few bits and bobs running more or less full time. When I go camping, I sometimes run out of battery, but there is not much more room to put leisure batteries and they are expensive.

The Zero FXS comes on trips, that's 7kw of power just sitting there and I wish I could use that. Could I get a 12v out from the bike easily and run my 12v car stuff from the bike in case I ever need it. The batteries on the car are wires with Anderson connectors, my thought was to just wire a plug form the bikes 12v directly to the 12v system on the car but I'm assuming I'd have to disconnect my solar to prevent it putting in power somehow.

Is there a better safe and simple way. I can solder and understand simple 12v stuff, but I'm not that good with the rest of the thongs mentioned above.

I have been hearing news reports lately regarding the new Ford Lightning electric pickup truck that claims that its battery will be able to power your entire home automatically, should your power go out. While a great idea, I assume that a certain amount of electrical infrastructure would be needed to be installed in your home to allow that to happen.   ???
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: Crissa on July 19, 2021, 01:00:05 AM
I have been hearing news reports lately regarding the new Ford Lightning electric pickup truck that claims that its battery will be able to power your entire home automatically, should your power go out. While a great idea, I assume that a certain amount of electrical infrastructure would be needed to be installed in your home to allow that to happen.   ???
Yeah, you'll need a transfer switch and the 'Ford Charge Station Pro' price currently unreleased.

-Crissa
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: mryan on July 19, 2021, 09:03:12 PM
I fried my 2.5kW inverter and I have not found a reasonably priced replacement. Inverters that can handle the full Zero battery voltage are rare.

DC to DC converter down to 12v and then the options are plentiful ;) I can't say you'll find a reasonably priced one however. There's this one, or elcon makes a 1kw version, maybe there's an ev that has a high kw version to salvage from.

https://www.electricmotorsport.com/isolated-600w-dc-dc-converters-48v-60-72v-96v-108-144v-to-12v-50a-select-model.html
Title: Re: Backup Power from Zero batteries - HOW TO
Post by: talon on November 18, 2021, 11:28:47 AM
A note on precharge, solar DC breakers seem to work pretty well. I understand breakers aren't made to be used as switches but it's a quick and dirty solution if you only rarely need to power down a load. Obviously this is ignoring many relevant safety considerations and should be used at your own risk. I don't know if the ampacity of a lithium battery could damage the input capacitors on the load so precharge may still be necessary.

Midnite's MNEDC and MNEPV breakers seem pretty nice, rated around 150VDC and any regular current rating you would need. At ~$20 this seems much less expensive than fuses and the highly reliable contactors. With the above considerations, if it was in a "fixed" location (not a vehicle) and installed in a proper enclosure I fail to see any reason personally to go another route.