Power supply disconnect sequence?

[rickst29]

Originally Posted by Autosnap

Thanks Jerry,

When we got back from Elkmont, we promptly went to the plateau for the week. I do live near Knoxville, but I don't know if I have a technical problem, per se, or if it's simply user error/ignorance of the system.

The mixing of the AC/DC through the converter, I think, is where i go off the rails.

I would prefer on the readouts to show the actual battery level rather than full because it's getting DC from the converter via AC shore power, however, I wouldn't want my boards to be unusable because they were pulling from the battery, I guess I'll just have to get used to that. Also, the factory solar does the same, so I assume it's wired in similarly. There's just not much recent information in the TM Manual and mine didn't come with a Solar manual, I'm trying to piece together what it is and it's capacity before I try to make any additions/changes. Thanks again, But I think I'll just have to wait till they are done moving the factory and then try to get a hold of the guys at TM.

Rick, where did you find a location to install your inverter and Lithium batteries? If you have a post, could you please point me in the right direction?

Thanks again guys, I've never felt so welcomed!

The '120 Volt AC' and '12 Volt DC' electrical systems are not really "mixed" at the Power Converter. The power converter contains lots of electronics (that's why they're expensive) which try to use power, taken from the 120-VAC A/C side, to generate and provide "12 Volt DC power" from the output terminals (they're wires, rather than "terminals") of the unit.

This is like a plug-in cellphone charger, expet thqt the power output is much higher, and the DC Output Voltage is higher (13.2 to 14.6 Volts, at various times with various settings) -- versus 5.0 volts for cellphones). Your cellphone only pulls a bit of power from the small charger - the cellphone itsself (and the USB power port in the charger) aren't really "mixed int

Unless a fuse is blown, the 12-VDC system will have a single high voltage level when big appliances are not pulling it down. This can be measured anywhere - such as a 12V cigarette-lighter outlet. Some of those plug-ins, while showing "12V" voltage, also provide 5 Volt cellphone charging ports (USB.)USB charging ports.

The factory solar includes only one small panel, many people install "bigger" systems. The "Solar" solar area has lots of information and pictures of installs, and posts about ways people habve chosen parts to use. The smae goes for other relectrical areas, including Lithium batteries.

[Autosnap]

Thanks again, Rick!
It seems like most of our electronics run on DC anyway. It would make more sense to have DC connections, those round plugs, not the cigarette lighter ones, but the smaller ones and forgo the loss of power that comes from converting to AC (lots of heat) then back to DC (more heat). But I guess the voltage differences can still be a problem. Anyway, I'll saunter over and see if I can find some good info to build out my system.

[rickst29]

Originally Posted by Autosnap

Thanks again, Rick!
It seems like most of our electronics run on DC anyway. It would make more sense to have DC connections, those round plugs, not the cigarette lighter ones, but the smaller ones and forgo the loss of power that comes from converting to AC (lots of heat) then back to DC (more heat). But I guess the voltage differences can still be a problem. Anyway, I'll saunter over and see if I can find some good info to build out my system.

The small 2-prong twist lock connectors (ML1-P and ML1-C) are hard to find and very expensive, roughly $11 per lug and $16 per socket. NEMA ratings are for AC only (in use as 2-wire connectors with no safety ground, that's why you can't find them - no one uses them for AC anymore).

But the legs are copper and held tight, supporting much higher current the cigarette sockets can handle safely. I feel that even 15A load is OK on those twist-lock pairs. The poor contact between loose 'cigarette lighter plugs' and the tiny contact at the bottom of the socket is far less trustworthy, I don't like using even 10A on through that combination. But I do have equipment, such as a tire pump, which tries to use 10A through "cigaratte lighte" connections when 120-VAC is not available.

'Anderson' connectors are cheaper and even better for 2-wire connections in "12V" plus "Grounding Return" DC connections.
- - - -
There are lots of small and cheap DC volt meters which accept wire connections opn the back, rather than providing a built-on cigarette plug. You could install one of those, although it would add another "phantom load" (running down the batteries while you're not travelling and not plugged in to replenish the batteries).

At higher cost ($50 and up) there are also "coulomb counter" meters. These show DC Voltage and Current with high accuracy. But they also keep track of the energy (in watts) - which is being sent through the meter in both directions. Users of LFP batteries are wise to add on of these meters, because the Voltage in a Lithium battery pack changes very little while the pack is between 85% full and 20% full.

I have two of those (on separate battery packs), even though just one would work fine. However, my cheap ones are NOT cellphone compatible, I can only see the power readings while inside the trailer.

My cellphone BMS units show both voltage and current, but they do not measure "remaining energy" (in Kilo-Watt hours) very accurately.