Lazy man wants inverter disconnect switch INSIDE trailer

[Bobbo]

We do a lot of boondocking, and the inverter draws battery power even when it is turned "off," so I installed a Blue Sea disconnect in the battery box to completely disable it. It didn't take me long, however, to get tired of going outside and opening the battery box to turn that battery switch on or off depending on whether we wanted to watch a DVD or TV at the time. When I looked at the trailer battery disconnect switch, I got an idea.

I bought an Intellitec Big Boy 200 amp latching relay, like the one the house disconnect uses, but double the size. I wasn't comfortable with a 100 amp relay on a 110 amp fused wire. (This is a continuous duty latching relay. Be careful because Intellitec also makes an intermittent duty non-latching battery isolator. The non-latching isolator is not what you want.)



The only wires not shown in that photo are the two 4g wires from the 110 amp fuse, and to the inverter. I left them off so the relay would be visible.

I also bought the same control panel and wiring harness that Airstream used for the battery disconnect.





I installed the control panel above the bed in the closet wall.



I ran the wiring to the back of the closet,



and down through an existing opening into the water heater space



I took it out between the aluminum wall and the plywood partition, then into the outside basement between the aluminum wall and the plywood partition.



I ran it around the outside basement at the very top.



After running it into the 12v electrical bay beside the outside basement, I bolted the relay to the wall and wired the harness to it. (Very first picture at the top.)

It needed a GROUND wire, so I made a 12g white jumper wire and ran it to the GROUND buss bar. I put a ring terminal on the other end and put that and the harness' GROUND wire under one of the mounting screws holding the relay against the wall.

One caution: when wired according to the schematic, pushing the USE switch turned the inverter off, and pushing the STORE switch turned the inverter on. I solved that by reversing the brown and white wires hooked to the relay. That reversed the polarity of the switch.

This was not a cheap mod, but now I can turn the inverter off and on without even getting out of bed.

No holes had to be drilled to run the wiring harness. The only permanent modification was cutting a 3"x3" square hole in the closet wall to mount the control panel. (I did have to cut the 5/16" ring terminal off of the inverter's 4g wire and install a 1/2" ring terminal so it would fit on the relay. I also had to buy a 3' long 4g wire with a 5/16" ring terminal and a 1/2" ring terminal. Genuinedealz.com shipped it to me ready to bolt on.)

[Bobbo]

AH64ID wrote:
If you're concerned about storage then your propane dector will kill it too

I have also moved the propane detector to the fuse block. The battery disconnect switch disables that too. But thanks for the heads up. I may not have thought about that.

AH64ID wrote:
, as will the radio and other parasitic draws.

Except, those draws are turned off by the battery disconnect switch.

AH64ID wrote:
If the trailer is parked and not being used the batteries need to be disconnected, not just the inverter. You cannot plan to leave the batteries connected over the winter.

I have tracked down all of the phantom draws, and with the inverter now disconnected, all phantom draws are gone. I have been leaving the batteries connected over the winter for 13 years. As long as you get rid of the phantom draws, that is not a problem.

AH64ID wrote:
It's not a whopping amount for a weekend of camping.

A weekend of camping, OK. But two weeks of boondocking, every little bit helps. We do a LOT of NFS or BLM camping without hookups.

AH64ID wrote:
Sure it's nice to shut if off from the inside, but I fail to see the need to.

"Need" is not the correct word. "Desire" is a better choice. Could I get by losing almost 5 amps a day while boondocking for two weeks or more? Sure. I did it. Until I added the Blue Sea disconnect. Could I get by having to go outside to turn the disconnect switch on or off every time I chose to watch TV or a DVD? Sure. I did it. Until I installed the relay.

AH64ID wrote:
IMO, you would have done better to spend the money on a pair of 6V batteries and a battery disconnect switch, or a non-WFCO product... but that's my 0.02 YMMV.

I didn't want more batteries. There was no easy place to install them. I have a battery disconnect switch, if you are interested. I don't use it anymore. The relay has replaced it. I agree that a non-WFCO product is a good solution, but it cost even more than this solution. And, the WFCO is perfectly adequate for its purpose, now that I have stopped its parasitic draw.

My mileage definitely varies. That is the great thing about this country, each person can find and use the solution that he deems the best. So far, no one has posted anything that makes me think, "hmmm, I should have done that."

Except for the expense of buying the relay, control panel, and wiring harness, I still see no downside to this install. It was a very easy install to accomplish. It was worth it to me to invest in this.

[AH64ID]

If you're concerned about storage then your propane dector will kill it too, as will the radio and other parasitic draws. If the trailer is parked and not being used the batteries need to be disconnected, not just the inverter. You cannot plan to leave the batteries connected over the winter.

It's not a whopping amount for a weekend of camping. Sure it's nice to shut if off from the inside, but I fail to see the need to.

IMO, you would have done better to spend the money on a pair of 6V batteries and a battery disconnect switch, or a non-WFCO product... but that's my 0.02 YMMV.

[Bobbo]

2oldman wrote:
0.2 a x 24 hour= 4.8 ah. Not a whopping amount.

OK, let's carry that on out.
0.2 a x 24 hours = 4.8 ah/day
4.8 ah/day x 7 days = 33.6 ah/week
33.6 ah/week x 4 weeks = 134.4 ah/month

If your trailer is sitting in storage over the winter, what will that do to your battery? Remember that a Group 24 battery has roughly 75 ah. Two of them, have roughly 150 ah, but you don't want to go below 50% charge, so 75 ah are available. At 4.8 ah/day, you hit the 50% mark at about 2 weeks, with EVERYTHING turned off. THAT is a whopping amount.

If you are boondocking and trying to conserve every amp-hour for your use, does that help or hurt? At 4.8 ah/day from a (usable) 75 ah in the battery, you are losing right at 6.5% of your battery's capacity EVERY DAY, just to the inverter (which is turned off). THAT is a whopping amount.

[2oldman]

I checked a few online, .2 amp is not bad.

My Outback 48v is 6 watts!

[time2roll]

200 milliamps is a lot for being OFF. Another sad WFCO product 😞

[2oldman]

0.2 a x 24 hour= 4.8 ah. Not a whopping amount.

[Bobbo]

Since it has been 2 years since I took measurements, and I didn't remember the numbers, I just went back out and took measurements again.
Inverter ON but no load is 1.67 amps
Inverter OFF is 0.2 amps. (It kept bouncing between 0.19 and 0.21.)

Even at 0.2 amps, I am glad I have the relay to disconnect it.

[2oldman]

Bobbo wrote:
Is this admitting that when powered off, it can pull over 2 amps of current, or am I misunderstanding what it is saying?

I don't think you're misunderstanding, but I think it's in error. That's a huge draw for being off.

[time2roll]

I think 2.4 is idle current when on but no load. That is crazy power for being off. Did you measure this? Maybe the remote is not functioning properly or the inverter power switch needs to be turned off. (see p7) The off switch should cut that power significantly. Although 2.4 at idle is still a bit high as most are closer to 1 amp per 1000 watts.

[Bobbo]

Some of you have inverters that pull 10 ma or less when off, I would like your opinion on the specs of this inverter. I have researched and found that I have a WFCO 5110R 1000 watt pure sine wave inverter. The manual has listed on page 14, under the specifications, that it has:

WFCO manual wrote:
Standby Current: < 2.4 A (Nominal)

Is this admitting that when powered off, it can pull over 2 amps of current, or am I misunderstanding what it is saying?

Here is the link to the online manual:

https://wfcoelectronics.com/wp-content/uploads/2019/11/5110R-Manual.pdf

[Bobbo]

ajriding wrote:
My inverter has an OFF switch that literally turns it off.
I am curious why your "off" switch does not turn it off.
By "turning it off" I mean that it cuts/disconnect the 12 volt positive power, literally separates the electrical contacts so no current can flow, from the batt to the inv.

I wonder the same thing. Knowing the quality and reliability of the WFCO converter/charges, I just chalked it up to a cheap WFCO inverter. I NOW have an off switch that does exactly that.

[time2roll]

And here I thought it was just the WFCO converters that are a disaster 😞

[ajriding]

My inverter has an OFF switch that literally turns it off.
I am curious why your "off" switch does not turn it off.
By "turning it off" I mean that it cuts/disconnect the 12 volt positive power, literally separates the electrical contacts so no current can flow, from the batt to the inv.

[Bobbo]

ktmrfs wrote:
interesting. If mine draws power in the "off" position it is less than 0.01A 10 ma.

I am sure you have a higher quality inverter than the cheap WFCO that Airstream put in my trailer. Mine draws a noticeable amount of power with my AC/DC clamp on meter.

time2roll wrote:
Job looks good. Seems like a lot of work to save 10 milliamps. Maybe another 100 watt solar panel would have been easier and fully automatic.

Mine is more than 10 ma. See the response to ktmrfs.

Fisherman wrote:
Checked my Go Power 300PSW, it says with the switch off, it draws no power from the battery.

See my response to ktmrfs