Connecting an inverter for emergency power

[Expalpo]

Does anyone have information or experience with connecting a pure sine wave inverter to the Spark's 12v service battery? This would be a good source of power during a grid outage and I have searched the internet for information or a kit, finding that there are conversions available for the Volt and Leaf only. I've contacted Chevrolet and asked what size inverter the AGM battery can handle and what the proper connection configuration would be, but as I expected they will not provide that information.

 

[Nashco]

First of all, the 12V battery is fairly small, so you would only want to use the inverter while the vehicle was powered on (with as many vehicle electrical loads shut down as possible). The Spark EV should be able to support a 1500W inverter. You could use the same kit as the Volt or Leaf...all you need is a fused power lead to wherever your inverter is located. There's tons of room under the hood for an inverter, if it is for emergency use only it seems that you could install some short cables and mount the inverter under the hood only when it is in use.

Bryce

 

[Expalpo]

Thank you Bryce I appreciate the reply and advice. I've seen quick connectors on Amazon that are designed for an application like this. So, by keeping the car "on" while using the inverter, I assume that the traction battery power flows through the AGM battery to the inverter, thereby allowing a long period of usage?

 

[nikwax]

er um "shut down" Bryce :lol:

 

[TonyWilliams]

Thank you Bryce I appreciate the reply and advice. I've seen quick connectors on Amazon that are designed for an application like this. So, by keeping the car "on" while using the inverter, I assume that the traction battery power flows through the AGM battery to the inverter, thereby allowing a long period of usage?

That's the general concept. The DC to DC converter will actually take the high voltage DC and bring it down to 13.5 volts at 100 amps maximum.

You can run your inverter from the 12 volt battery until you kill both the main traction battery, and shortly thereafter, the 12 volt battery.

 

[Expalpo]

Thanks Tony, if I ever get this figured out and implemented I'll be sure to keep an eye on the stored power and not let it completely deplete LOL! I have a grid-tied solar array that, during a power outage will still provide me (via an integrated 3 prong outlet) 1500 watts at 12 amps; providing the sun is shining. I'm hoping I can utilize this to intermittently recharge the Spark - another endeavor I'm unsure of. My complete lack of understanding in the field of electronics keeps me from moving forward. Can you tell me, is there a method to calculate how large an inverter my Spark 12 volt battery can accommodate without damage? I'd like to be able to at least cycle my refrigerator on and off and the mfg tells me that 1500 watts is adequate for that. By the way, all you folks who are offering your experience and expertise are appreciated.

 

[MrDRMorgan]

Thanks Tony, if I ever get this figured out and implemented I'll be sure to keep an eye on the stored power and not let it completely deplete LOL! I have a grid-tied solar array that, during a power outage will still provide me (via an integrated 3 prong outlet) 1500 watts at 12 amps; providing the sun is shining. I'm hoping I can utilize this to intermittently recharge the Spark - another endeavor I'm unsure of. My complete lack of understanding in the field of electronics keeps me from moving forward. Can you tell me, is there a method to calculate how large an inverter my Spark 12 volt battery can accommodate without damage? I'd like to be able to at least cycle my refrigerator on and off and the mfg tells me that 1500 watts is adequate for that. By the way, all you folks who are offering your experience and expertise are appreciated.

DON'T DO IT! Why? A 12 volt vehicle battery is not designed for long high-current discharging. Another battery type - deep cycle - is usually used for solar applications to drive an inverter and even these batteries have limits. For instance, a Surrette CS-25-PS deep cycle battery has a 974 amp-hr rating for a 100 hour discharge rate. But it drops to 639 amp-hr at 8 hours and even lower at 1 hour if it is even possible. Your cables from the battery to the inverter would have to big enough to handle the high current - think BIG battery cables - along with a disconnect switch and a 700 amp fuse. Think FIRE if you get it wrong!

You need to think of building a properly-designed stand-alone solar system feeding through a charge controller into a battery bank and then into the inverter. I highly recommend you get and read a copy of "The Solar Electricity Handbook" by Michael Boxwell. You can also log onto his website at http://www.solarelectricityhandbook.com.

Note - I have designed and built a 150 watt solar system with a controller and installed it on my 24 ft travel trailer. the solar system charges the 12 volt deep cycle battery which powers everything in my trailer except for the microwave and air conditioner. The refer runs off of propane and 12 volts. I have also used this same design to provide 12 volt DC power to a 300 watt pure sine wave 120VAC inverter. I used the 120 VAC from the inverter to power 4 security cameras and a recorder / video monitor.

 

[NORTON]

Guys, it's not Rocket Surgery.
You connect it 'red to red, black to black'. Have a fuse/circuit breaker close to the red connection.

You have a 21 kWh pack (on a '14). When the car is powered on the DC to DC converter is powering the 12V bus. The 12V battery just sits there on the bus doing nothing.
Chevy calls the DC to DC converter the APM, auxiliary power module, and it is the equivalent of a 100 A alternator. (maybe 120 A, forget where I read this spec)
It is fan cooled in the Volt and may be the exact same component in the Spark EV.

Don't pull more than 80% load. This is electronic projects GP's, Good Practice, General Principles... This is true for the APM and the inverter you are using.
This would be around 1080 watts (80A x 13.5 VDC), so using a 1500 watt inverter would work.
Just limit you power usage. Watts is Watts. Count them up.
If this keeps your house alive and safe from freezing, why not? All you should power is your natural gas furnace, the fridge and some lights.
At full power usage you should have 18 hrs of 1 kW of power usage, correct? Keeping the car in 'Ready' mode consumes some of the power.

Then you unplug and go to town and top up at a DCFC, if the town still has power, and Bob's your uncle ! Repeat.

Now here's the rub. What's to keep an unscrupulous EV owner from bringing Free Electrons home everyday?
This is a subject we should NOT speak of. There are still negative opinions about EV's and free charging the way it is now. If this get's out.....

 

[Expalpo]

Great information Norton, thanks for the education especially the calcs on how you worked this out - very helpful for someone like me - esp the 80% rule!

 

[SparkieVee]

Expalpo,

I've both run my fridge using an inverter and charged my Spark using the solar. I think you'll be fine.

I haven't used the Spark to run the inverter, but I've run it from other cars. I have an 800 watt continuous (1600 watt peak) inverter that had no problems running my newish, energy-star fridge. If your fridge uses more power, you may need a larger inverter. Just keep the load within what the Spark will handle.

After my solar was installed and inspected, but before the utility would let me connect, I used the SMA inverter's built-in outlet to charge the Spark a few times. It had no problems charging at 8 amps, showing just over 1000 watts flowing, but wouldn't do 12 amps - the car would stop charging, even though it's a 3KW system that produces over 2000 watts most of the day.

Personally, the next time I have a lengthy outage, I'll probably try to run the fridge directly from the solar inverter, but if that doesn't work I'll run the fridge from the car and top up the car from the solar.

 

[MrDRMorgan]

Expalpo,

I've both run my fridge using an inverter and charged my Spark using the solar. I think you'll be fine.

I haven't used the Spark to run the inverter, but I've run it from other cars. I have an 800 watt continuous (1600 watt peak) inverter that had no problems running my newish, energy-star fridge. If your fridge uses more power, you may need a larger inverter. Just keep the load within what the Spark will handle.

After my solar was installed and inspected, but before the utility would let me connect, I used the SMA inverter's built-in outlet to charge the Spark a few times. It had no problems charging at 8 amps, showing just over 1000 watts flowing, but wouldn't do 12 amps - the car would stop charging, even though it's a 3KW system that produces over 2000 watts most of the day.

Personally, the next time I have a lengthy outage, I'll probably try to run the fridge directly from the solar inverter, but if that doesn't work I'll run the fridge from the car and top up the car from the solar.

I am curious. How would you connect to the Spark's battery so you could draw sufficient current for the inverter? It looks like there is a fuse box mounted to and completely covering the positive post.

Post note: I took a closer look at the Spark EV battery posts and it is possible to connect a wire to each post. The only challenge would be to find a lug that would fit both the battery post and accommodate the required 5 AWG diameter wire.

 

[Expalpo]

SparkieVee -

Great news! I too have an SMA "Sunny Boy" inverter on my solar setup with the secure power supply option. Glad to hear that you've charged the Spark at the 8 amp level. I want to have the same options you've discussed: the ability to use the SMA's secure power supply when the sun is out and the Spark's power at night during a grid outage. Thank you for the post. If/when I get the Spark to power an inverter successfully, I'll post the results.

 

[scrambler]

Post note: I took a closer look at the Spark EV battery posts and it is possible to connect a wire to each post. The only challenge would be to find a lug that would fit both the battery post and accommodate the required 5 AWG diameter wire.

I know this is an old thread, but I was wondering if you (or someone else) ever found a good way to connect a 1500W power inverter cables to the Spark 12 V battery.

I just installed a quick disconnect set of cables in our volt so I could connect a 1500W power inverter for power outage, and would like to do the same on our spark, so we have two options.

But the lugs currently on the spark 12V battery don't look quite up to making a clean & sound connection to the kind of cables required for the inverter.

I would be curious to hear from anyone who would have made a power inverter connection to the Spark.

 

[NORTON]

1500 watts can be 107 AMPS.
This is giving the car's APM a work out at full load.
You probably won't ever come close to using it at full load.
If you don't tap in at the bigazz battery cables, where can you tap in?
A 100 AMP fuse right near the Positive battery post is the proper way to make for a safe installation.

 

[scrambler]

1500 watts can be 107 AMPS.
This is giving the car's APM a work out at full load.
You probably won't ever come close to using it at full load.
If you don't tap in at the bigazz battery cables, where can you tap in?
A 100 AMP fuse right near the Positive battery post is the proper way to make for a safe installation.

The inverter is 1500W, but I would not draw more than 1200W like for the Volt Gen 2.
I definitely use a 100A fuse or breaker close to the Plus connection for added safety.

My question was about a clean way to connect to the battery terminals.
On the Volt you have clean large bolts accessible for both the plus and minus.
On the spark, the only thing really accessible are the battery terminals, and they don't offer a large bolt connection for the thick cables.

I was wondering if others had done this and come up with specific ways to attach thick cables permanently to the battery terminal with a quick connect / disconnect connector for the inverter cables.

 

[NORTON]

...On the spark, the only thing really accessible are the battery terminals, and they don't offer a large bolt connection for the thick cables.
.... specific ways to attach thick cables permanently to the battery terminal with a quick connect / disconnect connector for the inverter cables.

Anderson SBS series connectors, good to 105 Amps.
4 ga. to 1/4" ring terminals and large area washers on both sides of the ring terminal/battery bolt connection.
You may have to buy longer bolts for the existing battery clamps.
And of course the inline fuse holder between the positive clamp and the Anderson connector.
The ring terminals and Anderson pin/sockets should be professionally crimped onto the 4 ga. wire, but you might be able to solder them with enough heat...

This is way more power than the car's APM is ever asked to produce in real life. Do you really need this much power?

 

[scrambler]

4 ga. to 1/4" ring terminals and large area washers on both sides of the ring terminal/battery bolt connection.
You may have to buy longer bolts for the existing battery clamps.

That is the part I have a problem with, unlike the Volt, the Spark existing battery terminals/clamps do not have a place for a large bolt, so it seems I would have to undo the existing terminals/clamps and replace them by different one, and if so, this is the part I am unsure of. I dont know if it is easy or not to remove the existing ones and put new ones, and which ones.
On top of that, the plus Terminal has a very specific structure to connect at least to cables right now, so not sure if any standard terminal/clamp could be easily used.

I will most likely not be using all the inverter power, as I would most likely just connect a fridge, the cable modem, and eventually the TV and a few LED lamps.

 

[NORTON]

>... the Spark existing battery terminals/clamps do not have a place for a large bolt, so it seems I would have to undo the existing terminals/clamps and replace them by different one, ...

>>I will most likely not be using all the inverter power, as I would most likely just connect a fridge, the cable modem, and eventually the TV and a few LED lamps.

>That's where the big gauge/ small bolt hole ring terminal comes in.
With a wide area washer on both sides of this ring terminal the small metric bolt on these battery clamps should make a good contact path.
But, as you said this could all be changed with adapter battery clamps. I have seen the crazy high power car audio amp suppliers offer strange adapters for clamping to the battery posts. Some even have built in high power fuse holders.

>>Yeah, that's why building up with a 1500 W inverter may be an overkill. You could survey the appliances you want to power with a 'Kill a Watt'.
How long will your house run before you have to 'Go to town and bring home some electrons from the free DCFC?"

If you really want to be a prepper you need a gas generator and the adapter cable to unplug the drier, turn off the Main CB, plug in the generator and live in a normal house.,,, until you run out of gas...

When was the last time you lost power?
My 400 W inverter came with alligator clamps.

 

[scrambler]

I already have a pas powered generator for two sump pumps in my yard, so this is just clean power for house electronics.

We use to only have outages once or twice a year during big storms, but they lasted from 1/2 days to 3 days. An we had 3 outages during a few hours now in the last two weeks...

Still no closer to a solution for hooking onto the battery terminals without redoing the whole cable to battery terminal connectors though...

 

[NORTON]

...Still no closer to a solution ...

Small mounting hole (1/4") / big gauge ring terminals. Why can't these be bolted to longer (if needed) battery clamp bolts?

Are you saying you'd like to buy a ready made kit and don't want to assemble these cables?

I wish I knew how to post pics here since photobucket stopped working. :?

I have these ring terminals at work and I can show one next to the battery clamp bolts. This would be a good solid connection.

Are people posting pics any more on this site? :?: