Cigarette port causing short circuit on controller

[NewDCGuy]

So I built a battery box with solar charge controller and various auxiliary ports for charging etc.

I have the negatives in a string that leads back to the battery (thru the load port of the scc) and a separate switch for turning on the voltmeter and powering the fuse panel (separate switches for each auxiliary port as well).

The situation is this: I power on the unit, all looking good but when I plug in a 75w inverter into one of the cigarette auxiliary ports (nothing plugged in) and flip the switch, the inverter light does not light up, the voltmeter cuts off and the auxiliary switch loses power. When I turn off the auxiliary port with the inverter attached and wait a few seconds, the switch light turns back on and the voltmeter powers back on. I checked all inline and fuse panel fuses and all are OK. I tried on the second cigarette port and it did exactly the same thing. When it all comes back online, the lighter ports work with other devices just fine...just NOT the inverter.

UPDATE: I bought a new inverter (same specs as the original) and tried again...same issue! I then realized that my renogy wanderer (10amp) is throwing a E04 code which means load short circuit. Any idea why a short circuit would happen here before anything is plugged into the inverter? After unplugging the inverter and restarting the controller all is fine again. So strange! I suppose I could bypass the controller or wire a cigarette port for the inverter directly to the battery to see what happens? Maybe rule out some things? Thoughts?

Any thoughts are appreciated! I'm a novice here! Just looking for some answers.

 

[NewDCGuy]

Just provided an update to the situation in case it helps provide some thoughts

 

[Whinny]

You should not be trying to power your inverter through the "load" port of a solar controller, they have a low current capability. Also search for topics on "pre charge".

 

[chrisski]

Your inverter should work. 75 watts is not a lot of power and I suspect less amps than using the heating element to light a cigarette.

If you buy a low wattage inverter like that at an auto parts store, it should work.

I suspect your car senses it and shuts the port off. Perhaps a surge, or perhaps the power is dirty.


In my older cars, a 75 watt inverter would be fine. I’ve used up to 400 watt inverters through the cigarette port. The inverter stops working at some point. It will run all items, but not a mattress inflator or play station. Those work fine when hooked ditesctlt to your battery.

I think you have a newer car with smarter computers than my 20 year old ford.

 

[williamsk913]

So I built a battery box with solar charge controller and various auxiliary ports for charging etc.

I have the negatives in a string that leads back to the battery (thru the load port of the scc) and a separate switch for turning on the voltmeter and powering the fuse panel (separate switches for each auxiliary port as well).

The situation is this: I power on the unit, all looking good but when I plug in a 75w inverter into one of the cigarette auxiliary ports (nothing plugged in) and flip the switch, the inverter light does not light up, the voltmeter cuts off and the auxiliary switch loses power. When I turn off the auxiliary port with the inverter attached and wait a few seconds, the switch light turns back on and the voltmeter powers back on. I checked all inline and fuse panel fuses and all are OK. I tried on the second cigarette port and it did exactly the same thing. When it all comes back online, the lighter ports work with other devices just fine...just NOT the inverter.

UPDATE: I bought a new inverter (same specs as the original) and tried again...same issue! I then realized that my renogy wanderer (10amp) is throwing a E04 code which means load short circuit. Any idea why a short circuit would happen here before anything is plugged into the inverter? After unplugging the inverter and restarting the controller all is fine again. So strange! I suppose I could bypass the controller or wire a cigarette port for the inverter directly to the battery to see what happens? Maybe rule out some things? Thoughts?

Any thoughts are appreciated! I'm a novice here! Just looking for some answers.

I think the other poster is on the right track. Your inverter is likely charging a capacitor at start-up and exceeding low amp rating of load. That's a guess. Try his suggestion on precharging and if it solves the issue when plugged in, you have found your cause. I have high amp 12 volt power points on my battery box, but I have it connected directly to battery with an appropriately sized fuse. I'd probably just rewire it directly to battery.

 

[NewDCGuy]

Thanks folks. I too found it strange to cause that issue with such a small inverter (with no load even) in the cigarette port. A bigger inverter I could understand but such a small one seems strange to me.

When emailing renogy cs they say it's an issue with the inverter but given the fact it has happened with two inverters (one being brand new, same 75w power), I find that unlikely. Also strange how they don't seem to say anything about not using the load port for these purposes. I don't even see any warnings or limits to load capacity in the renogy documentation so how would one know this unless being on a forum such as this?

I figure what I may do is redirect the accessory switch directly to the battery (rather than to the renogy scc load) and see what happens. I'll turn the load function off on the scc. If any short continues it can hopefully be handled through the battery bms. I'll split the battery connectors so one goes to the accessories and the other to the scc (for when using solar to recharge the battery) - both with their own switch to turn on.

Perhaps going through the load port also explains why I'm only able to pull 1.3 amps when charging several smart devices, despite them being connected to 2.1amp usb ports.

Seem like a reasonable approach? Just don't want to wreck anything!

 

[chrisski]

Is this a car? When I see cigarette lighter I think vehicle, but this could be a home build also.

 

[NewDCGuy]

Home build inside a toolbox for rainy day power outages ;-).

 

[chrisski]

Home build inside a toolbox for rainy day power outages ;-).

Well I guess what I said about a cigarette lighter in a car earlier does not apply!!

I wish there was a "standard" DC plug like there is for AC. I'm not a fan of using cigarette lighters in builds, but they are the easiest thing to install through. I use 24volt USB C and normal QC 3.0 ports. I also use Anderson PowerPole connectors. I use the 50 amp battery connectors, and the 45 amp normal power poles.

 

[NewDCGuy]

Thanks for your input folks! Update for you: I turned off the 'load' on the scc and disconnected the wires from the posts. I split the wiring from the battery 2 ways: One, for the accessory switch and two, to power the scc in the event of solar charging. When I plugged the same inverter RENOGY told me was faulty, it powered up no problem...no 'short circuits'! It works perfectly. Clearly the load port on the scc was not designed for any real load to be connected. I'll have to send a follow up to Renogy cs to let them know how I fixed the issue they were supposed to be helping me with ;-).

Now another rookie question...now that the load terminals are no longer in use on the scc and the loads are all being handled directly from the battery, will I need to worry about the charging/discharging when charging with solar and using the ports at the same time? I figured the load connections before were there to help manage the solar input and the power output but now that the output is turned off, will it all work the same or do I have anything to worry about?

Thanks again! So much to learn but really really exciting and fun!

 

[chrisski]

split the wiring from the battery 2 ways: One, for the accessory switch and two, to power the scc in the event of solar charging. When I plugged the same inverter RENOGY told me was faulty, it powered up no problem.

Those “Load” terminals on SCCs are really lacking in documentation. THe best I’ve seen is statements like don’t plug your inverter in, and the worst was no documentation.

You’d think with all the different SCCs that have them, you’d have documentation that says ”No more than XX Watts.”

You’ll be fine Wired as is. Instead of wired at the battery, each wire could connect to its own stud on a busbar. Which a low watt 75 watt inverter, you should be fine. Just make sure its lug to lug contact and no steel between them.

When I first started, I thought solar was like wind and you needed something hooked to it. Now, I don’t think that load terminals serve any useful purpose.

 

[crossy]

When I first started, I thought solar was like wind and you needed something hooked to it. Now, I don’t think that load terminals serve any useful purpose.

Yeah, I use the load connector on our basic PowMr SCC to turn our LED floodlights on and off at night. 48V pack powering 12V LEDs via a buck converter, only an amp or two (5A limit according to the book of words) from the load connector.

 

[Zil]

Use the CC to charge a battery. Use the battery to power the outlet.

 

[OneStudPuppy]

So I built a battery box with solar charge controller and various auxiliary ports for charging etc.

I have the negatives in a string that leads back to the battery (thru the load port of the scc) and a separate switch for turning on the voltmeter and powering the fuse panel (separate switches for each auxiliary port as well).

The situation is this: I power on the unit, all looking good but when I plug in a 75w inverter into one of the cigarette auxiliary ports (nothing plugged in) and flip the switch, the inverter light does not light up, the voltmeter cuts off and the auxiliary switch loses power. When I turn off the auxiliary port with the inverter attached and wait a few seconds, the switch light turns back on and the voltmeter powers back on. I checked all inline and fuse panel fuses and all are OK. I tried on the second cigarette port and it did exactly the same thing. When it all comes back online, the lighter ports work with other devices just fine...just NOT the inverter.

UPDATE: I bought a new inverter (same specs as the original) and tried again...same issue! I then realized that my renogy wanderer (10amp) is throwing a E04 code which means load short circuit. Any idea why a short circuit would happen here before anything is plugged into the inverter? After unplugging the inverter and restarting the controller all is fine again. So strange! I suppose I could bypass the controller or wire a cigarette port for the inverter directly to the battery to see what happens? Maybe rule out some things? Thoughts?

Any thoughts are appreciated! I'm a novice here! Just looking for some answers.

I had similar in my vehicle. And can be VERY hidden. Power ports have a general standard but on my vehicle one it seems there was a crack or somehow the very back had a spot that the shell and the middle center all the way back was shorting. I’d suspect that power plug port. While not common I have banged my head on the dashboard of my truck with this same issue. Once the power port was changed I quit blowing random fuses on accessories