Since your indicated that you have the TrippLite Inverter/Charger I thought I would add some specific to that. As you probably already know the tripplite has a switch that looks pretty much like this.
My secondary question would be if you have the ASRM installed, it is a remote option that hooks in the RJ45 connector left of the above switch.
My SMB came with ASRM minus panel, it was also unfortunately installed about 10 inches away from the actual inverter, which made it pretty much useless. I have since moved it but that is off topic.
If you have the remote installed, the switch would be left in the Auto/Remote (left).
If you do not have a remote, this would put the inverter in auto mode. "Switch to this mode when you need constant, uninterrupted AC power for connected appliances and equipment. The Inverter/Charger will continue to supply AC power to connected equipment and to charge your connected batteries while utility or generator-supplied AC power is present. Since the inverter is ON (but in Standby) in this mode, it will automatically switch to your battery system to supply AC power to connected
equipment in the absence of a utility/generator source or in over/under voltage situations."
So if you are plugged in you do not need this to be on. The drawbacks if you left this on, would be if you are plugged in and using some AC appliance and said plugged power goes away, the inverter would automatically cycle over and provide AC until it ran the battery to low. In my case my water heater is a electric/propane unit, so if I plug in at a campground and turn on my water heater, if I left for the day and came back and found that the campground had lost power, I would have drained my battery trying to keep the water heater going. The second case would be when not plugged and not using any AC power. Even without supplying inverted power it will use some battery power up, so it would be best to be off or in charge only.
- "Switch to this mode when you are not using connected appliances and equipment in order to conserve battery power by disabling the inverter. The Inverter/Charger will continue to supply AC power to connected equipment and charge connected batteries while utility- or generator-supplied AC power is present. However, since the inverter is OFF in this mode, it WILL NOT supply AC power to connected equipment in the absence of a utility/generator source or in over/under voltage situations."
This is where my inverter stays at 95% of the time. There is really no negative consequence to being in this settings even if you are not plugged in.
- "Switch to this mode to prevent the inverter from drawing power from the batteries. Use this switch to automatically reset the unit if it shuts down due to overload or overheating. First remove the excessive load or allow the unit to sufficiently cool (applicable to your situation). Switch to “DC OFF”, then back to “AUTO/REMOTE” or “CHARGE ONLY” as desired."
Note: I use the DC Off setting when plugging in a "hot" plug. ( Or at least I would recommend it). Since it is not really easy to get that switch, I try to make sure the plug is not hot when plugging into the SMB. (Most Campground power Stands have breakers). If your power source is from a GFI plug you will need to have the switch in Auto/remote mode while plugging in, after that you can move it over to charge only. Plugging in from a GFI source with it set to charge only will reset GFI plug.
If you have the remote, then you leave that switch on auto and then have two options on the remote switch. Auto/Invert and Charge only. The Remote will give you the charge Only setting and the Auto Invert mode. I have moved this to a more accessible location. I will keep this in on the charge only setting unless I need the inverter ( in my case that would mean to fire off the coffee pot or microwave)
On either the inverter itself or the remote there are some LED indicators. The left side are for Battery Voltage or charge rate. If you are charging the batteries the LED's indicate the following:
CHARGE RATE INDICATION (Approximate)
CONTROL SWITCH IS IN THE "CHRG ONLY" OR “LINE/CHARGE ONLY” POSITION
LEDs Illuminated Charge Rate
All three lights on Overcharge error†
Red 75% - 100%
Red & yellow 50% - 75%
Yellow 25% - 50%
Green 0% - 25%
All three lights off 0%
If you are auto invert mode:
BATTERY CHARGE INDICATION (Approximate)†
CONTROL SWITCH IS IN THE "AUTO" OR “AUTO/INVERT” POSITION
LEDs Illuminated Battery Capacity (Charging/Discharging)
Green & Yellow 81%–90%
Yellow & Red 41%–60%
All three lights off 1%–20%
Flashing red 0% (Inverter shutdown)††
† Charge levels listed are approximate. Actual conditions vary depending on battery condition and load.
†† Inverter shutdown protects battery against damage due to excessive discharge.
LEDs Illuminated Fault Condition
All three lights Excessive discharge (Inverter shutdown)
All three lights Overcharge (Charger shutdown)
The LED's on the right will indicate the following
“LINE” LED: This green light will turn continuously ON whenever connected equipment
is receiving utility-supplied AC power and your Inverter/Charger is set to
“AUTO/REMOTE,” meaning that it will automatically switch to battery power if AC power
becomes unavailable. The light will flash intermittently when connected equipment is
receiving utility power and your Inverter/Charger’s Operating Mode Switch is set to “CHRG
ONLY” to indicate that the Inverter/Charger’s inverter is OFF and that the Inverter/Charger
will not supply power from connected batteries.
“INV” LED: This yellow light will turn continuously ON whenever connected equipment is
receiving battery-supplied AC power. It will flash if the Inverter/Charger does not detect the
minimum load necessary to activate the inverter.
“LOAD” LED: This red light will turn continuously ON when your Inverter/Charger is
receiving utility-supplied AC power and the load is between 80% and 110% of capacity to
alert you that the inverter might not be able to support the load. The light will flash
intermittently after the Inverter/Charger's inverter shuts down due to a severe overload or
I hope all this helps. As others have said some things depend on your set up. Using the inverter for a microwave or coffee pot can use up a lot of battery power. My coffee pot will take about 10% of my battery power to make a pot of coffee. As Dave said this can be offset if you start the van and idle will using the inverter for that short period. Note: due to the automatic disconnect of separator it is possible that at idle ,the alternator is not providing enough power to keep the separator closed while running a microwave.
I hope all this help, and enjoy your new camper.