Good point. I did measure the surge wattage as it starts and it is about 600 watts. My inverter capacity is 1000 watts continuous, 2000 watts surge.

 

You need to measure the surge current. The power factor is poor when the motor starts. The motor label may list a related value, VA that indicates the power needed when the power facot is considered.

 

Thank you for the information.

 

I tested my inverter today and it starts and runs the the refrigerator just fine. The caution is valid, however, to buy a large enough inverter to handle the starting surge current.

 

I did some more research on 12v inverter use by Prius owners and found there is a concern with blowing the fuse that protects the DC/DC inverter if there is excessive current draw.

So for example, if you hooked a large 12 volt to 110 volt inverter to the 12 volt battery and the required current from the DC/DC inverter exceeded the fuse rating, it would blow, resulting in a fairly large expense to replace it.

My question is how is the FEH DC/DC inverter protected? Does it have a fuse or circuit breaker and if so, what is the rated amperage? I believe this would be in the shop manual, if anyone has one.

Thanks in advance.

 

The 330v DC to 14v DC converter is on the passenger side.
The 12v battery is on the driver side.

There is a fused link part 151-2 in the front of the car between the radiator and the engine that connects

I could not find the amp rating, but the wire is 6 gauge... which is jumper cable grade, and is 100+ amps.

-John

 

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.

 

Found a positive ID on the DC/DC converter from PCED manual Section1:

"The purpose of the DC/DC converter is to function as an alternator in a conventional powertrain. Because the converter does not use any moving parts, the low voltage battery is charged when the vehicle drives with the engine ON or OFF. This is accomplished by converting power from the high voltage traction battery to a regulated nominal 14.5 volts, while supplying a load current of up to 110 amps."

 

Thanks, John.

So this tells us the fuse link is a minimum of 110 amps. If I stuck in a 100 amp fuse after it, I could ensure that I would never blow the fusible link.

I need to think about this a bit to decide how best to proceed.

 

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.