12V socket oddity July 04, 2023, 06:46:14 pm Hooking up a 45watt AC TV to a 300 watt pure sine inverter, which in turn goes into the auxiliary 12 volt outlet in the cabinet near the TV. Should just work fine but the TV boots halfway up then trips something in the inverter, and cycles.Ok, maybe a bad inverter?If I try the other 12V outlet in the back of the RV, TV boots up fine, as you would expect.Shouldn’t be any difference between the two 12V outlets, right?The one that doesn’t work reads 13.3 volts, the one that works reads 13.6.For that matter, all three other sockets up front read 13.6.So that socket that fails is just delivering 13.3, which is likely the source of the problem, but what would make a socket deliver just 13.3 when all the others deliver 13.6?
Re: 12V socket oddity Reply #1 – July 04, 2023, 07:19:56 pm Hi Dave; I take it that all of these outlets are running off of your LiF batteries. Maybe a bad ground, or some surge or not quite right connection problem. RonB
Re: 12V socket oddity Reply #2 – July 04, 2023, 07:24:03 pm Quote from: RonB - July 04, 2023, 07:19:56 pmHi Dave; I take it that all of these outlets are running off of your LiF batteries. Maybe a bad ground, or some surge or not quite right connection problem. RonBThey should be all off the house (LiF) batteries.I’ll try a new socket.Thanks Ron!
Re: 12V socket oddity Reply #3 – July 04, 2023, 07:41:07 pm BTW, not at all urgent to fix the 12v socket, it’s just odd that it’s not working properly compared to the other four inside.I’ve hardwired the 300 watt inverter to the old Jensen power cable, which works and allows me to use the existing TV switch. The inverter was surplus since the solar upgrade. This hack will do until I can run 120V AC up there.
Re: 12V socket oddity Reply #4 – July 04, 2023, 11:06:52 pm Quote from: Dave Katleman - July 04, 2023, 07:41:07 pmBTW, not at all urgent to fix the 12v socket, it’s just odd that it’s not working properly compared to the other four inside.I’ve hardwired the 300 watt inverter to the old Jensen power cable, which works and allows me to use the existing TV switch. The inverter was surplus since the solar upgrade. This hack will do until I can run 120V AC up there.Wow I never thought of doing this on my new LED 22” Vizio TV I have running off the inverter into my 12v socket. Jeez I wouldn’t think 13.3 would make any difference. That certainly is odd. 1 Likes
Re: 12V socket oddity Reply #5 – July 04, 2023, 11:52:19 pm Quote from: brewersarcade - July 04, 2023, 11:06:52 pmWow I never thought of doing this on my new LED 22” Vizio TV I have running off the inverter into my 12v socket. Jeez I wouldn’t think 13.3 would make any difference. That certainly is odd.I'm guessing there is a connection problem in the socket wiring causing too much resistance. The inverter draw drops the socket voltage low enough to trigger the inverter's "low voltage cutoff".
Re: 12V socket oddity Reply #6 – July 04, 2023, 11:52:56 pm The no current drain voltage of a lithium battery is 13.3 volts. Do you have a charger running of some sort to get 13.6? What is the voltage at the 12 volt outlet with the inverter and TV running? The inverter manual will tell you what input voltage it alarms at.I have an RB and the 12 volt outlet near the TV cannot support anything due to voltage drop. Somehow the original Jensen? TV worked. I paralleled the wiring to the socket with 8 gauge wire, not much change. I had to install a voltage stabilizer to make a 12 volt TV work.Then Starlink came along with a 300 watt inverter. No go. I ran 6 gauge wire, power and ground, direct to the lithium battery circuit breaker. The inverter and Starlink now work. I never have found where the 1.5 volt drop in the original wiring came from. It didn’t even seem to depend on current. If you install an inverter near the TV mount in an RB run it’s own heavy wiring direct to the battery.
Re: 12V socket oddity Reply #7 – July 05, 2023, 12:51:54 am Quote from: hbn7hj - July 04, 2023, 11:52:56 pmThe no current drain voltage of a lithium battery is 13.3 volts. Do you have a charger running of some sort to get 13.6? What is the voltage at the 12 volt outlet with the inverter and TV running? The inverter manual will tell you what input voltage it alarms at.I have an RB and the 12 volt outlet near the TV cannot support anything due to voltage drop. Somehow the original Jensen? TV worked. I paralleled the wiring to the socket with 8 gauge wire, not much change. I had to install a voltage stabilizer to make a 12 volt TV work.Nothing special was done or active on any of the five 12V outlets in the TK. It’s only that 12V outlet near the TV that experiences the drop, every other outlet shows 13.6. Since you have similar issues, might be something inherently different how Lazy Daze did the 12V wiring for the TV & that 12V socket.The inverter wired up to the old Jensen power cable works better, but still fails under load. So I need to do more work, maybe tap into the other 12V wiring.
Re: 12V socket oddity Reply #8 – July 05, 2023, 01:23:15 am Quote from: Dave Katleman - July 05, 2023, 12:51:54 amNothing special was done or active on any of the five 12V outlets in the TK. It’s only that 12V outlet near the TV that experiences the drop, every other outlet shows 13.6. Since you have similar issues, might be something inherently different how Lazy Daze did the 12V wiring for the TV & that 12V socket.The inverter wired up to the old Jensen power cable works better, but still fails under load. So I need to do more work, maybe tap into the other 12V wiring.Just an opinion but forget the original wiring. Run 6 gauge wiring including ground through a circuit breaker to the battery.On the RB from the TV you have 2/3 the length of the coach then under the floor to the power panel. all 10 gauge, then back across the floor and forward a bit to the batteries. Maybe 8 gauge. I never was able to trace the ground path, also 10 gauge. Maybe 25 ft. of 10 gauge plus the ground length. Too much wire resistance for the RB. 1 Likes
Re: 12V socket oddity Reply #9 – July 05, 2023, 10:23:13 am A 300W inverter can draw 25 amps from the battery to supply 2.5 amps at 120VAC. Possibly, it would be easier to mount the inverter near the battery, then run, say, 14-18 AWG 120VAC wiring to the TV set area.
Re: 12V socket oddity Reply #10 – July 05, 2023, 11:39:25 am "Possibly, it would be easier to mount the inverter near the battery, then run, say, 14-18 AWG 120VAC wiring to the TV set area."Right. That's what Lazy Daze did when installing an inverter to power a satellite TV receiver. Voltage drop in 120 V wiring is only one tenth that in 12 V wiring, so it's always better to use a short run of 12 V wiring to the inverter and a long run of 120 wiring to the appliance.But about the 12.3 V vs. 12.6 V puzzle: true, that doesn't sound like much of a difference. But if I understand Dave correctly, those are no-load voltages. I've seen cases where no-load voltage looks OK, but as soon as you start to try to pull some current, the voltage drops quite a bit more than you might expect--the wiring just can't carry the load. Bottom line: it pays to be cautious about drawing conclusions from no-load voltage measurements.Now, we know from the fact that Dave's rear outlet shows a lower no-load voltage that there is some voltage drop happening between the batteries and that outlet, probably due either to poor contacts at the socket or inadequate wiring. I'm guessing that if it were possible to measure the voltage at that outlet when the TV is turned on, you'd see it drop enough to make the TV unhappy. 2 Likes
Re: 12V socket oddity Reply #11 – July 05, 2023, 12:57:02 pm Thanks Andy; I knew that! and should have mentioned that to Dave. I assumed that those voltages were measured during use, and connected to the load. 13.6volts is open circuit for the LiF batteries. 13.3 volts is under some load, but may indicate a bad connection also. Dave has undergone the Lithium battery conversion, (AM solar). Some equipment is in the space below the closet, and in the newer 'TK the TV is located on that wall passenger side, instead of the back corner driver side where my flip up shelf is. The older 'TK's did not come with a TV, but was wired and had the Winegard amplifier switch and socket. That socket may not be up to the task of supplying an inverter. Mine has a 7 amp fuse in the converter distribution fuse board. My 19" TV only draws 3.2 amps (12v) with a simple 75 watt plug in inverter. RonB
Re: 12V socket oddity Reply #12 – July 05, 2023, 07:30:37 pm Quote from: Dave Katleman - July 04, 2023, 06:46:14 pmThe one that doesn’t work reads 13.3 volts, the one that works reads 13.6.For that matter, all three other sockets up front read 13.6.There is a load on the circuit reading 13.3V that is dropping the voltage reading by 0.3V due to cabling resistances. This is likely due to a poor connection in the run somewhere rather than a big phantom load, and would explain why you have a problem when you connect the tv. If this socket is the one that has the antenna DC supply, you might want to pull it out and check for some issue with the connections on the circuit board - such as a cold solder joint.Steve
Re: 12V socket oddity Reply #13 – July 05, 2023, 10:37:40 pm Quote from: Andy Baird - July 05, 2023, 11:39:25 amBut about the 12.3 V vs. 12.6 V puzzle: true, that doesn't sound like much of a difference. But if I understand Dave correctly, those are no-load voltages. I've seen cases where no-load voltage looks OK, but as soon as you start to try to pull some current, the voltage drops quite a bit more than you might expect--the wiring just can't carry the load. Bottom line: it pays to be cautious about drawing conclusions from no-load voltage measurements.Now, we know from the fact that Dave's rear outlet shows a lower no-load voltage that there is some voltage drop happening between the batteries and that outlet, probably due either to poor contacts at the socket or inadequate wiring. I'm guessing that if it were possible to measure the voltage at that outlet when the TV is turned on, you'd see it drop enough to make the TV unhappy.Yes, all measurements were with zero load, just for comparison purposes as a first step to understanding why one socket was having issues and the other four were working as expected.
Re: 12V socket oddity Reply #14 – July 06, 2023, 02:30:05 pm "all measurements were with zero load"Understood. It's hard to get a measurement from a 12 V socket under load. No-load measurements are easy--just unplug whatever was plugged in and stick in your probes. But to get a measurement while the socket is actually in use, you'd have to have access to its rear--and that's usually buried inside a wall or cabinet. Getting to those rear contacts can be difficult or impossible.
Re: 12V socket oddity Reply #15 – July 06, 2023, 07:19:58 pm Hi Dave, and Andy; I'd measure that voltage at the fuse in the power distribution center. See what voltage it changes to under load. I installed a PD4655 in a friends Thor, and the person connecting the LP gas detector had pushed the wire in too far and the set screw was on the vinyl insulation. So only barely connected. I'm sure the previous owner(s) had problems with that sensor. I'm not sure that there was anything else on that branch circuit. If Dave had his converter and fuse board replaced at AM Solar, a similar thing could have happened. Or maybe the screw is just loose. A good place to start. RonB 1 Likes
Re: 12V socket oddity Reply #16 – July 06, 2023, 08:10:31 pm "I'd measure that voltage at the fuse in the power distribution center."Couldn't hurt, but that measurement wouldn't tell you anything about the two most likely causes of low voltage at the 12 V outlet: voltage drop in the wiring from the power center to the outlet, and a poor connection from that wiring to the back of the outlet. 1 Likes
Re: 12V socket oddity Reply #17 – July 07, 2023, 10:23:59 am Quote from: Andy Baird - July 06, 2023, 02:30:05 pm"all measurements were with zero load"Understood. It's hard to get a measurement from a 12 V socket under load. No-load measurements are easy--just unplug whatever was plugged in and stick in your probes. But to get a measurement while the socket is actually in use, you'd have to have access to its rear--and that's usually buried inside a wall or cabinet. Getting to those rear contacts can be difficult or impossible.There are nifty plug-in power socket adaptors that have a voltage readout. Here's one, but lots more, and on cords, too:Amazon.com: [2023 Upgraded] Cigarette Lighter Splitter, SUPERONE 180W... 1 Likes As an Amazon Associate Lazy Daze Owners' Group earns from qualifying purchases.
Re: 12V socket oddity Reply #18 – July 07, 2023, 12:55:04 pm Hi Andy; Quote" but that measurement wouldn't tell you anything about the two most likely causes of low voltage at the 12 V outlet:" Step one in trouble shooting: if you suspect the wiring, or socket, which are hard to get to and/or inspect the length of wiring; first verify that it isn't an issue with the power center/fuse board, fuse or connection at the beginning of that long run of wire. Dave's motorhome is pretty new, but went through a lot of 'trauma' during his LIF conversion. And it was a used motorhome, so no one knows for sure if there are manufacturing defects, or previous disturbances to the wiring runs, etc. The fuse in question at the power center may not have any other 'appliances' connected to it other than the socket in question. But it absolutely was disturbed during the upgrade (of the converter) so I would start there. It is also easy to access, and check the quality of that one, and the other branch connections, while you are at it. It also has the advantage of being able to monitor the voltage as it is put under load, or has the load varied. RonB
Re: 12V socket oddity Reply #19 – July 07, 2023, 02:26:59 pm All good points, Ron, and I agree that the power center/fusebox is the place to start. However, the voltage under load at the power center probably won't tell you much about the voltage under load at the other end (the socket). If there's voltage drop in the wiring, it won't be visible at the power center--only at the socket end of the circuit. That was the point I was trying to make. 1 Likes
Re: 12V socket oddity Reply #20 – July 07, 2023, 08:57:18 pm Checking my Lazy Daze owners manual for my 2003 T/K I find that the 12V outlet for the TV is only rated for 8 amps. Could your inverter be drawing too many amps for this outlet?My 12V outlet for a TV has a button that can be pressed to boost the reception. It can be hard to see that it has a button there. When turned on it has a light displaying power is on. I generally do not use this outlet as my understanding it does not handle much load. My T/K has an additional normal 12V outlet beneath it. That is the one I normally use. JohnF
Re: 12V socket oddity Reply #21 – July 07, 2023, 10:31:25 pm "My 12V outlet for a TV has a button that can be pressed to boost the reception."That outlet comes from the roof antenna which has a 'Pre-amplifier", hence the boost.
Re: 12V socket oddity Reply #22 – July 08, 2023, 01:13:52 am Quote from: JohnF - July 07, 2023, 08:57:18 pmChecking my Lazy Daze owners manual for my 2003 T/K I find that the 12V outlet for the TV is only rated for 8 amps. Could your inverter be drawing too many amps for this outlet?It’s a 300 watt inverter, if I remember the formula, divide the watts by 120V, that’s just 2.5 amps.The TV only needs a maximum of 95 watts, well under the 300 watts.
Re: 12V socket oddity Reply #23 – July 08, 2023, 04:18:56 am Hi Dave and Andy. I'd start at the fuse board, but I think there may be a bad connection somewhere along the way to that socket, and most likely at that socket. The whole plate should be easy to unscrew so the back can be inspected. I'm suspicious about the inverter. They have a huge surge current, and large capacitors to stabilize the 12 volts as it is 'switched' up to 110vAC. At 300 Watt inverter can draw more than 23 amps, but since the TV's nominal load is 45 Watts, It may draw much more than that just for an instant, enough to have the small inverter shut off. My true Sine Wave inverter doesn't allow any grounding, and the neutral output can not be referenced to ground. That particular 12v socket does run 12v dc up the RF cable to power the pre amp in the Sensar head, so the shield is grounded, and the TV/inverter might not like that setup. My little 75 watt inverter has no problem with my 19" TV, so I'd have to see this problem live. So Dave, you have a 3kw inverter as part of the LIF upgrade, yes? You should be able to run the TV off of that. Or get a cheap extension cord (no ground wire) to run the 300 W inverter 110v to the TV wherever it is. RonB As an aside: my 2KW inverter runs about 15 watts idle wasted for small loads, cooling fans not on. That inefficiency gets worse with more power being used)
Re: 12V socket oddity Reply #24 – July 08, 2023, 06:40:40 am Quote from: RonB - July 08, 2023, 04:18:56 am So Dave, you have a 3kw inverter as part of the LIF upgrade, yes? You should be able to run the TV off of that. Or get a cheap extension cord (no ground wire) to run the 300 W inverter 110v to the TV wherever it is. RonBYep, that’s been my workaround until I have downtime to tinker a bit more with the connections, probably in a few weeks.
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