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guyffe

New member
Joined
Dec 1, 2017
Messages
3
Anyone try attaching a portable inverter to the FFE 12v battery to power household devices? If so, what size/type of inverter did you use? That is probably determined by the DC-DC charging rate?

I would like to get this lined up for the next power outage and curious how large an inverter I can get, as well as the best way to connect it.

Thanks for any tips!
 
Somebody correct me if I am wrong but I think the DC-DC converter can only put out 100A which means you only have 1200W max available using the 12V system. If you really want to do this the right way you would find an inverter that runs off the HVB and can provide much more power. I imagine you could figure out a way to hook it up thru the high voltage junction box on top of the TCM (traction control module) In much the same way Sefs added the CHAdeMO charge port. You would need a way for the inverter to shut itself off once the battery voltage gets down to a certain point so that you don't over discharge the battery and kill it. You'll have to find out the HVB specs are in order to do this. And who knows where you'd be able to find an inverter capable of the high voltage. If you manage to do this without electrocuting yourself, please share. I'd probably never bother to do this but would be curious to know how and how much it costs.
 
I've used a small 150W inverter in power outage emergencies from a car 12v accessory jack.
It was plenty for emergency uses to power a light, a low power LCD TV, etc.
The longest power outage I've had over the past several years only lasted a few hours so that was good enough for that.
 
Great feedback everyone, Thanks!

@triangles - is there a way I can confirm DC-DC charging maxes out at 100amps?

- Also, do you think I could oversize the inverter to handle the inrush of say the refrigerator? For example, could I use a 3,000watt inverter knowing the continuous load would be less than 1,00watts?

- lastly, how do I connect the terminals? Positive on the battery positive terminal and negative on the negative terminal....or the frame of the car?
 
guyffe said:
Great feedback everyone, Thanks!

@triangles - is there a way I can confirm DC-DC charging maxes out at 100amps?

- Also, do you think I could oversize the inverter to handle the inrush of say the refrigerator? For example, could I use a 3,000watt inverter knowing the continuous load would be less than 1,00watts?

- lastly, how do I connect the terminals? Positive on the battery positive terminal and negative on the negative terminal....or the frame of the car?
Positive to positive, negative to negative.
Not sure you'd need to oversize it like that, keep in mind many inverters already have a "peak" vs "continuous" rating too. The battery can absorb some peaking load over what the DC-DC converter can do.

I'd get an OBD-2 dongle and FORScan or FORScan Lite (phone) setup working so you can monitor the DC-DC state when experimenting.
 
I dont get it. I thought the 12v battery was pretty much dead weight unless you were driving the car or had it plugged in. If you have the car running in the driveway, it will charge the 12v battery? Enough so even that you could use one of those inverters to power stuff? I have one and have used it for hurricaine duty several times albeit connected to a running ice vehicle. Or are you saying that youre tapping the lithium battery to run an inverter from?
 
Carbuff said:
I dont get it. I thought the 12v battery was pretty much dead weight unless you were driving the car or had it plugged in. If you have the car running in the driveway, it will charge the 12v battery? Enough so even that you could use one of those inverters to power stuff? I have one and have used it for hurricaine duty several times albeit connected to a running ice vehicle. Or are you saying that youre tapping the lithium battery to run an inverter from?
IIRC the DC-DC converter is active whenever the high voltage battery's contactors are switched on, so it'll charge the 12V battery...
 
Carbuff, spirilis is correct. The DC-DC converter essentially does the same function as an alternator in an ICE car.

guyffe, I remember finding that specification 100A several years ago, unfortunately I don't remember where I found it. I'm assuming you could verify that if you had access to a factory service manual. Maybe the parts guy or gal at a dealer could look that up for you.
 
Well, thats good to know. I thought it only charged through the regen braking system.
 
That said, something about cooking power transistors designed to do light-duty work most of the time disturbs me. I'd definitely only use that in emergencies only. Of course, the car has a nice liquid cooling system, so maybe it's not too big a deal.
 
I think I will buy a 1,500watt inverter with 3,000watt inrush. Has anyone heard of any ill effects to the car’a electrical system?
 
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