There are a number of 1000w continuous inverters on Amazon in that price range. Which one did you get? How did you connect all of your devices? How depleted did the Clarity battery get?
Clarity as a back-up power source? (DC-DC converter size, idle behavior)
- Thread starter M.M.
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MNSteve
Well-Known Member
The small 1500-watt units are very quiet, produce minimal emissions, are easy to use, and require very little maintenance. I came to love them when deployed to Puerto Rico for Maria. They are hugely different from the big bulky generators that I was used to. Most of us can survive with 1500 watts. The biggest stumbling block for me is the heating fan which requires some effort to switch over; everything else can temporarily run using extension cords. But I have vanishingly few power outages so I can't justify a more extensive solution.
Remember to consider the size of the 12V power cables that you will need. This area gets confusing quickly, because there are inverter ratings for peak load versus continuous load. Sometimes the 12V bus will be 13V to 14V, but just to quickly consider cables take 12V as an example.
Say you buy a 12V 2kW Xantrex inverter and plan to run 1500W continuous (or, at least have that capability). Assuming 100% conversion efficiency, you need to be able to supply 1500W/12V, or about 125A! (at 85% inverter efficiency, closer to 150A) That is the very problem with working at 12V instead of using the Traction battery more directly (not possible at present) where 1500W/365V(I forget the actual number for Clarity, just to show the idea) = a measly 4A!
Back to 12V (1,500W) for 125A continuous (still assuming 100% conversion efficiency), you should use a relatively large #2 cable, the proper crimp or bolt connectors, heavy Anderson type connectors, and proper fusing or a circuit breaker. It's very doable, just messy. I used a marine #2 cable with an outer loom covering for the plus cable on my gen 1 Volt (before I switched to a 2kW Honda generator). Also, study fuse open curves, because a 125A fuse, might open in minutes or longer for smaller overloads, and that might be enough time to damage the Clarity's DC-DC converter, or to overheat the wires. I was using BUSS MRC marine breakers, I think I had a 135A breaker in the Volt with the #2 marine cable. I don't remember the details, but the gen 1 Volt APM (DC-DC converter) was very robust. The gen 1 Volt battery was in the back behind the passenger seats, easy to get to under the hatchback, and it was easy to have an installed inverter out of the weather.
If you leave pigtails permanently installed (most practical), or some wiring of 125A circuit permanently installed in Clarity, some thought needs to go into crash protection. For example, the cable from the battery to the fuse or circuit breaker should be considered carefully both for length and vicinity to metal structural members, because a short to ground before the fuse or breaker is a dead short 12V battery overload with great fire hazard.
It's definitely doable, but considering all the stuff to buy, build, and install, most folks (especially with a remote home where they can leave something there) should consider a 2kW - 3kW inverter generator. They are very reliable these days, run quietly for hours, and are easy to re-fill. Best part, no risk of damage to Clarity if something goes wrong.
random google picture of a MRCB type breaker:
Say you buy a 12V 2kW Xantrex inverter and plan to run 1500W continuous (or, at least have that capability). Assuming 100% conversion efficiency, you need to be able to supply 1500W/12V, or about 125A! (at 85% inverter efficiency, closer to 150A) That is the very problem with working at 12V instead of using the Traction battery more directly (not possible at present) where 1500W/365V(I forget the actual number for Clarity, just to show the idea) = a measly 4A!
Back to 12V (1,500W) for 125A continuous (still assuming 100% conversion efficiency), you should use a relatively large #2 cable, the proper crimp or bolt connectors, heavy Anderson type connectors, and proper fusing or a circuit breaker. It's very doable, just messy. I used a marine #2 cable with an outer loom covering for the plus cable on my gen 1 Volt (before I switched to a 2kW Honda generator). Also, study fuse open curves, because a 125A fuse, might open in minutes or longer for smaller overloads, and that might be enough time to damage the Clarity's DC-DC converter, or to overheat the wires. I was using BUSS MRC marine breakers, I think I had a 135A breaker in the Volt with the #2 marine cable. I don't remember the details, but the gen 1 Volt APM (DC-DC converter) was very robust. The gen 1 Volt battery was in the back behind the passenger seats, easy to get to under the hatchback, and it was easy to have an installed inverter out of the weather.
If you leave pigtails permanently installed (most practical), or some wiring of 125A circuit permanently installed in Clarity, some thought needs to go into crash protection. For example, the cable from the battery to the fuse or circuit breaker should be considered carefully both for length and vicinity to metal structural members, because a short to ground before the fuse or breaker is a dead short 12V battery overload with great fire hazard.
It's definitely doable, but considering all the stuff to buy, build, and install, most folks (especially with a remote home where they can leave something there) should consider a 2kW - 3kW inverter generator. They are very reliable these days, run quietly for hours, and are easy to re-fill. Best part, no risk of damage to Clarity if something goes wrong.
random google picture of a MRCB type breaker:
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Regarding the cables, my solution to this, and the one I’d highly recommend, is to get a high-current DC quick connect something like this one. (Note: That’s not a specific part recommendation, just an example.)
If you attach that with ring lugs to your 12V battery (preferably with in-line overcurrent protection) as a short pigtail, it can easily be stored capped in a dry location under the hood. Then bring out the longer cables with mating connector that’s already attached to your inverter and plug it in when you need it. Lets you get hooked up quickly without actually modifying the car, and keeps terminal contact resistance to a minimum where alligator clamps will not. You also might be able to snake the cable through the grille or under the engine well to keep the hood latched while in use. Plus you can’t accidentally hook it up backwards if you build it right.
Other thing to keep in mind, as snowllof went into above: A lot of the pre-built inverter kits (usually designed for trucks at job sites) I’ve seen come with 4ga or even smaller cables. They are almost certainly undersized for even a 1000W load. Any decent inverter is going to have a low-voltage shutdown (intended to protect the battery from over-discharge). These are usually in the 10.5V-11.5V range. So whatever battery cable size you use needs to take into account the voltage at the terminals, minus whatever drop from the contact resistance of the connectors, minus drop through the cable at higher load, such that it’s still above the shut-off value for the inverter.
I experimented with the clarity using heavy internal loads (AC on high, seat heaters both on full, headlights on), and it appears (probably to extend life of the 12V battery) that it cycles the DC-DC converter on and off rather than just holding it at float voltage at all times. I’ve seen voltages as low as 11.68V (alternating with about 12.53V, which seems to be the charge/float voltage level of the converter).
So with a 10.5V cutoff on the inverter, you need to make sure that the cumulative voltage drop across all cables and connectors is less than 1V at around 1A/10W of AC output. That’s around 100A for a 1000W inverter.
Assuming you have the DC cables strung in to your garage from the driveway (so you don’t kill yourself with CO from the exhaust), you’re looking at 10-15’ of cable, so once you factor in contact resistance at both ends (and maybe a quick connect) you’re almost certainly going to need at least 2ga, and I’d probably use 1/0 or even 2/0 to be sure.
A tip, welding cable is more expensive but has much finer strands so is drastically more flexible, so is much nicer to work with if you’re routing it. It’s also easy to find in huge sizes at industrial supply places.
The Gadgeteer
Active Member
DANGER: You should not connect an inverter to house wiring even through a transfer switch unless the inverter was specifically designed to do so. Problem with inverters in the hundreds of dollars range, even the true sine wave ones, do not produce power the same way as you get power in your house. In your house the neutral and ground are bonded together. The inverter companies use cost saving techniques and circuitry that is not and the long and short of it if you connect to your house you will end up with about 80 volts AC live from the negative on the battery to ground. This is dangerous and if that battery is in a car then the car body is likely connected to negative side of the battery. Now you a potential of 80 volts AC between the car and ground. I imagine there is also a danger to the electronics. Anyway I was researching connecting my inverter to my transfer switch shortly after hurricane Sandy when I came across this information. Only the direct hardwire inverters are safe to connect to your house as far as I know.
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ShrimpBurrito
New Member
Hi Ho Silver - What battery terminals did you connect the inverter to? There’s only one terminal on the positive side, and so that’s obvious, but the negative side has 2 places to connect up to:
1) as bolt that tightens the clamp around the battery post, and
2) another bolt that attaches a large wire to a plate connected to the post. But in between that other bolt and the battery post is a mysterious black box with a small wire connected to it....almost looks like it’s a sensor of some sort.
See attached photo.
Dave
1) as bolt that tightens the clamp around the battery post, and
2) another bolt that attaches a large wire to a plate connected to the post. But in between that other bolt and the battery post is a mysterious black box with a small wire connected to it....almost looks like it’s a sensor of some sort.
See attached photo.
Dave
I would connect your inverter after the ELD(black box) this will allow the car to see the load and increase the power from the dc/dc converter and step up the voltage a little.
The Gadgeteer
Active Member
Could there be an issue running high continuous current through the ELD?
I could not find the exact model that Honda is using, but a similar model states that "The use of such a low-value shunt should permit the IBS unit to operate at a current range of ± 600 A continuously and ± 2,000 A in pulsed applications not exceeding 900 J"
You really should not continuously exceed the rating of the onboard DC/DC converter as that would drain the small 12v battery quickly. The sensor should be rated for at least the capacity of the converter and probably more. Also being on the opposite battery side of the eld the only current it will see is the difference of the converter and what you are pulling from the 12v with battery your inverter which should be a small amount or short surge currents.
Cash Traylor
Well-Known Member
Also, the current loads and thermal status of the DC-DC converter is a CAN buss monitored unit with DTC logs both live and "frozen." If you exceed the ratings and it fails - I doubt it would be covered under warranty. There is no normal load that the 12 volt system nor battery could create that would consume 2300 watts for anything more than a few minutes (the battery would blow). So you get 170 amps max depending on system voltage. The battery system is fused at 175 (however that is for charging the battery only, so the distribution of that load is likely planned at around 140 amps. Just a note of caution, as the Clarity is a really expensive generator compared to other options. The DC-DC converter is $1350 on it's own, and if you blow it and trip the immobilizer, you might also have to pay the towing to your dealer for the repair. Each to his own... I like the idea and have done it with the small 1000 watt inverters. However why anyone would consider attaching a large inverter that pushes all the limits of what is normally a very low 12 volt system demand in this car is confusing. Honda monitors the Clarity well, the telemetrics system gathers an amazing about of CAN data. Anyway, if you are in a tough spot an need power, from anywhere and this is your "plan B" if you real generator quits, then I fully get it. However to PLAN to use this at more than 1000 watts continuous for any duration is likely unwise.
After I read this in the Owner's Manual, I bought one ($15) just to see what such a thing looks like.
Cash Traylor
Well-Known Member
@insightman , Fusable links get pretty big. I have some 800-1000 amp ones and they look like copper bars with holes drilled in the ends and two slits cut in the middle to create the "fuse" part. Have never been around one to see it blow, but have heard it - and let's say I had to go change! I have a DIY CD Welder that is capable of about 6000+ amps at around 400+ watt-seconds. I messed up one day and - well, there are things that get your attention - fully...
Cheers, Cash
Cheers, Cash
ShrimpBurrito
New Member
Personally, I am considering only using a 1000 watt pure sine wave inverter, and only to power a household refrigerator in case of prolonged power failure.
Today I used a clamp on ammeter to measure the DC current next to the ELD. Putting the car in the “accessory” mode (two pushes of the START button without depressing the brake) appears to enable the use of all electrical accessories in the cabin EXCEPT the heat, and further, does not turn on the DC-DC converter. In this scenario, I was able to get a current draw off the 12v battery of about 65 amps. Head lights, seat heaters, rear defroster, A/C, radio, and fan.
Putting the car in “Run” mode, i.e. ready to drive, with all those accessories still on, current dropped to a 5-7 amp charge, so that’s a total of a 70+ amp output on the DC-DC converter.
No wipers, and of course, no cabin heat (and one would be using both the A/C and cabin heat when the front defroster is on). So a 100 amp load seems pretty reasonable under normal operating conditions. And that would be comparable with all those accessories off, but with the inverter connected (1000 watt output on the inverter, divided by 10 volt input = 100 amps max).
Cash - what has been your experience in using the 1000 watt inverters? What kind of load was connected?
Today I used a clamp on ammeter to measure the DC current next to the ELD. Putting the car in the “accessory” mode (two pushes of the START button without depressing the brake) appears to enable the use of all electrical accessories in the cabin EXCEPT the heat, and further, does not turn on the DC-DC converter. In this scenario, I was able to get a current draw off the 12v battery of about 65 amps. Head lights, seat heaters, rear defroster, A/C, radio, and fan.
Putting the car in “Run” mode, i.e. ready to drive, with all those accessories still on, current dropped to a 5-7 amp charge, so that’s a total of a 70+ amp output on the DC-DC converter.
No wipers, and of course, no cabin heat (and one would be using both the A/C and cabin heat when the front defroster is on). So a 100 amp load seems pretty reasonable under normal operating conditions. And that would be comparable with all those accessories off, but with the inverter connected (1000 watt output on the inverter, divided by 10 volt input = 100 amps max).
Cash - what has been your experience in using the 1000 watt inverters? What kind of load was connected?
Cash Traylor
Well-Known Member
Cabin heat (which is actually coolant system heat) and air conditioning are HV loads, so will not impact the 12 volt system (other than the cabin blower, it is 12 volts). You should have no issue at those loads with that inverter. However, you cannot see the load on the DC-DC buss as it does not all "go through the battery" regarding the ELD, 90% powers systems directly. Only a small amount goes to the 12volt battery to charge it. The 12 volt battery in your Clarity never has to "start" the car so unless you run it in "acc" mode it is never discharged much at all. Closing the HV contactors only takes a few amps for a second, once those are closed, the DC-DC converter powers everything. It is primarily there for a safety mechanism and for first responders to "safe" the car, accessory use if you don't turn the car on and to power the standby items in the car when it is "Off" (HV pack disabled), and in the event your DC-DC converter actually failed or thermally shut down due to coolant issues, it will briefly power the EPS and vehicle safety system (lights etc) while you limp home keeping the HV contactor closed. However, that will be like limping any car home when the "alternator" failed - not a long trip, especially at night, and we have a smaller 12v battery than most cars this size.
The DC-DC converter provides 14.4 volts to the DC 12 volt buss, so that is what you will get as long as you have appropriate sized cables. The battery is floats at 14+ volts while the car is "ON" if it drops below 13.3 a DTC will be set, and below 10.8 (I think, have to look that back up) you will get system MIL/DTC codes frozen so that may be an issue if you have to get an inspection soon (EPA flags set until enough drive/ICE cycles). You will also get a several dash flags until you drive for a while.
I never had trouble with the inverter, but I never pulled the full 1000 watts, at max was 600 to run the fridge. I hated having the car outside the garage (normally when you need a gen it is due to bad weather) hood cracked open, and it "on" where someone could just break the window and drive away (silently), and with my inverter. I have a portable 8000 watt Harbor Fright
240volt generator for home power emergencies. It was $550 with coupon, does everything I need very infrequently, and I don't have to worry about damaging my car or it driving away. It can power most of my house easy, and has a few times. I get that it is cool, and it is a nice thing to have in your back pocket. However for me, it is plan "C", the power has to fail, my generator fail, then I will consider hooking up my car to my refrigerator.
Cheers,
Cash
The DC-DC converter provides 14.4 volts to the DC 12 volt buss, so that is what you will get as long as you have appropriate sized cables. The battery is floats at 14+ volts while the car is "ON" if it drops below 13.3 a DTC will be set, and below 10.8 (I think, have to look that back up) you will get system MIL/DTC codes frozen so that may be an issue if you have to get an inspection soon (EPA flags set until enough drive/ICE cycles). You will also get a several dash flags until you drive for a while.
I never had trouble with the inverter, but I never pulled the full 1000 watts, at max was 600 to run the fridge. I hated having the car outside the garage (normally when you need a gen it is due to bad weather) hood cracked open, and it "on" where someone could just break the window and drive away (silently), and with my inverter. I have a portable 8000 watt Harbor Fright
240volt generator for home power emergencies. It was $550 with coupon, does everything I need very infrequently, and I don't have to worry about damaging my car or it driving away. It can power most of my house easy, and has a few times. I get that it is cool, and it is a nice thing to have in your back pocket. However for me, it is plan "C", the power has to fail, my generator fail, then I will consider hooking up my car to my refrigerator. Cheers,
Cash
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Mowcowbell
Well-Known Member
We have frequent power outages in tornado alley... usually half a dozen or so a year.
I'm going to start shopping for a whole house generator once folks get back to work. Having a backup that kicks on automatically, runs on natural gas and provides enough power to run the entire house is my goal.
I'm going to start shopping for a whole house generator once folks get back to work. Having a backup that kicks on automatically, runs on natural gas and provides enough power to run the entire house is my goal.
CyberDyneSystems
Member
I hate to sound stupid, but I am going to ask. Why is it that every time someone brings up using a Clarity for temp emergency power, the discussion is always focused on the 12volt system?
Every car has that, but with our plug in cars we have massive amounts of HV voltage. Why isn't the discussion about bypassing the limitations of the ubiquitous 12volt system and tieing into the real batteries and the charger that keeps them topped off?
Every car has that, but with our plug in cars we have massive amounts of HV voltage. Why isn't the discussion about bypassing the limitations of the ubiquitous 12volt system and tieing into the real batteries and the charger that keeps them topped off?
CyberDyneSystems
Member
Really? At what point is this bonding occurring? Certainly not what I have come to expect.
The more expensive Japanese Clarity PHEV has a DC Fast Charge port in addition to the J1772 port. It offers a place to plug in Honda's Power Exporter 9000 (perhaps named for it's $9,000 price), which converts the HV battery voltage for home use. If there's an English-language version of the Japanese Honda Express, perhaps you can reverse-engineer the HV wiring of the Japanese Clarity PHEV and then figure out how to build a cheaper Power Exporter.
Chademo systems can have this as it is part of the protocol (V2G) for Chademo. Thus the Nissan Leaf can do this, but the equipment is costly.
https://insideevs.com/news/341220/nissan-leaf-powers-up-automakers-us-headquarters/
https://www.nissan-global.com/EN/ZEROEMISSION/APPROACH/COMPREHENSIVE/ECOSYSTEM/
The Honda power exporter, I believe is the same concept.
https://uk.motor1.com/news/371467/honda-charging-solutions-home-public-v2g/
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The Gadgeteer
Active Member
At the point near where the power enters your house inside your breaker box. Not what I expected either.
Anyone able to explain it in a couple of sentences ground neutral bonding?