Inverter question - Page 3 - GreenHybrid

08FEH · #21 (**permalink**) 01-20-2008, 10:20 PM

Quote:

Originally Posted by travelover

Thanks John. My 12 volt inverter is 2000 watts surge, which at 12 volts is 167 amps. Hopefully most of that comes off the lead acid battery, but it would be a drag if it blew the fused link.

Do you know where the 6 gauge wire attaches to the battery? I'm thinking that a fuse there, smaller (amperage) than the fused link, would protect the link during 12 v inverter use.

Thanks.

Wait a second though, I don't think the inverters are rated in such a way as to draw in 12v dc as they make in 110v ac. Are they?

If the inverter can surge 2000 watts A/C, that does not mean it draws an equal (converted) draw in DC... does it?

Sean

Wbruff · #22 (**permalink**) 01-21-2008, 04:04 AM

Quote:

Originally Posted by 08FEH

Wait a second though, I don't think the inverters are rated in such a way as to draw in 12v dc as they make in 110v ac. Are they?

If the inverter can surge 2000 watts A/C, that does not mean it draws an equal (converted) draw in DC... does it?

Sean

Yes Power in watts is equal to the voltage applied multiplied by the current drawn. Power remains constant less any losses due to inefficiencies of the converter. roughly power in = power out. or in another way to figure out the current draw would be to take that 2000 watts and divide it by the 12 volts and come up with 166.6 amps at 12 volts No free ride by using 12volts, otherwise I'd run my entire house on 12 volts.

gpsman1 · #23 (**permalink**) 01-21-2008, 07:12 AM

Quote:

Originally Posted by prg

I have been considering the same. One thing that has me concerned is how the DC-DC converter would fare if under significant load over a fair period of time. By design it may be able to provide 110 amps, but it should only need to do this for very short periods of time as the FEH really does not have much to operate at 12 volts. Pulling 100 amps through an inverter would keep the DC-DC converter at max, poss overheat/failure, etc.

#1 the DC/DC converter is liquid cooled and that is what the second yellow tank of coolant is for under the hood.

#2 The FEH has MORE 12v devices than a traditional car. The 12v coolant pump is just one example. It has more actual devices... but I can't be sure this means more amps overall.

#3 If you run your headlamps / parking lamps, fans, etc... then obviously you will have less current available to run your power inverter.

#4 If you turn on every possible option in the car, the 12v draw is about 100 amps... and the car can sustain this indefinately.

-John