finishing installing Battery Disconnect and power inverter

[dpgllg]

My 2017 Grand Design draws power to Co2 detector and Slide 2 even when battery disconnect is turned off. The slide when in blocks the back of 5th wheel and the dealer said this is a safety device.

Well I'm going to install a battery disconnect that will kill everything when off and also a small power inverter.

My question is will the power inverter draw power from the battery when the inverter is not being used? I went online and some say yes others no so I'm really not sure.

What I would like is to connect the inverter to the disconnect switch and when power is on BUT I'm not actually using the inverter it will not draw from battery.

There is a power switch on inverter and I would keep this at off until I wanted to use inverter.

Thanks!

Dave

[brulaz]

Even when in storage, battery self-discharge is prolly more important than the draw from a turned-off inverter.

I wouldn't worry about over nite scenarios anyway.

But for longer term storage, you will want a battery tender to handle the self-discharge issue alone and it should also be able to handle the turned-off inverter as well.

Adding another heavy duty switch just for the inverter seems like over-kill.

[MrWizard]

dpgllg wrote:

MrWizard wrote:
This ^

Disconnect for RV storage, not while camping

When camping and not using INVERTER power for something
Just turn the inverter off, the control drain, is not going to have any noticable affect on your camping power use

MrWizard I think your message got truncated

i was referring to post right above by time2roll

thats why the 'up arrow' pointing to post
instead of quoting him

i agree with what time2roll said

under traveling/camping conditions, the minor amount of inverter control drain in the off mode is insignificant
it really only comes into play to amount to anything if allowed to to be an ongoing thing while in storage

[BFL13]

dpgllg wrote:

BFL13 wrote:
There is a difference between a switch for the 120v side of an inverter and one for the DC side. The DC side needs to be beefy for the ampacity of the inverter to battery wiring. The DC switch will have different amp ratings for 12v and 24v too.

I have some cheaper DC switches good to 100amps. I noticed that when "open" they still "leak" a little, so that is another thing with switches.

For storage, it seems easier IMO to remove the wires from a battery post.

I already have this switch to completely shut off the power to everything.

Battery Disconnect

If there is a concern about the inverter drawing to much power while shut off I would add another on of these to control power to the inverter.

We do not dry camp but might stop overnight at a rest area to get some sleep. That is where my concern came from the inverter draining battery while power is on but inverter is not being used.

You can use your multi-meter on volts and check each side of the switch when it is open. Might find a small voltage "leak", which would be no better than having the inverter's 120v "off", but still drawing a little. Or that switch might be high quality with no leakage.

[dpgllg]

MrWizard wrote:
This ^

Disconnect for RV storage, not while camping

When camping and not using INVERTER power for something
Just turn the inverter off, the control drain, is not going to have any noticable affect on your camping power use

MrWizard I think your message got truncated

[dpgllg]

BFL13 wrote:
There is a difference between a switch for the 120v side of an inverter and one for the DC side. The DC side needs to be beefy for the ampacity of the inverter to battery wiring. The DC switch will have different amp ratings for 12v and 24v too.

I have some cheaper DC switches good to 100amps. I noticed that when "open" they still "leak" a little, so that is another thing with switches.

For storage, it seems easier IMO to remove the wires from a battery post.

I already have this switch to completely shut off the power to everything.

Battery Disconnect

If there is a concern about the inverter drawing to much power while shut off I would add another on of these to control power to the inverter.

We do not dry camp but might stop overnight at a rest area to get some sleep. That is where my concern came from the inverter draining battery while power is on but inverter is not being used.

[BFL13]

There is a difference between a switch for the 120v side of an inverter and one for the DC side. The DC side needs to be beefy for the ampacity of the inverter to battery wiring. The DC switch will have different amp ratings for 12v and 24v too.

I have some cheaper DC switches good to 100amps. I noticed that when "open" they still "leak" a little, so that is another thing with switches.

For storage, it seems easier IMO to remove the wires from a battery post.

[MrWizard]

This ^

Disconnect for RV storage, not while camping

When camping and not using INVERTER power for something
Just turn the inverter off, the control drain, is not going to have any noticable affect on your camping power use

[time2roll]

Doubt you will notice while in use. Only time to really disconnect is during storage.

Better to focus on recharging system while in use.

[dpgllg]

MrWizard wrote:
Inverters mfg today
Most will draw something, when off
Because they are not truly off

The switches are control switches, not main power switch, they are too small to carry even the 25 amp load of a 300w inverter
No way are they going to carry the power of a larger inverter
If they built them with mechanical electrical relays operated by the switch
There would be no drain when off
But it's all electronic controls, and there is always some drain,
For storage mode you need a mains power disconnect

If I am reading you correctly I can use a disconnect switch to control the invertor. So under my new scheme of things I will have a battery disconnect to everything and then another that just controls power to the inverter. Is this correct?

I want to prevent battery drain while using power to the 5th wheel and when I'm not using the inverter.

Am I missing anything?

Dave

[brulaz]

brulaz wrote:
With mine, as long as the inverter power switch is off, no power is drawn.

After reading time2roll and the wiz's replies above, I should change this to "little power is drawn", possibly a few milliamps?

Say 10mA, or 0.24 Ah per day, or 3 Wh per day?

According to the daily solar charging logs when in storage, typically 50 Wh per day were used to maintain the batteries when all other parasitic loads are disconnected (other than the inverter, turned off, and the solar charger). So prolly not a major issue relative to battery self-discharge.

[MrWizard]

Inverters mfg today
Most will draw something, when off
Because they are not truly off

The switches are control switches, not main power switch, they are too small to carry even the 25 amp load of a 300w inverter
No way are they going to carry the power of a larger inverter
If they built them with mechanical electrical relays operated by the switch
There would be no drain when off
But it's all electronic controls, and there is always some drain,
For storage mode you need a mains power disconnect

[time2roll]

My Xantrex 1800 seemed to draw power even when switched off. Not much as I would guess just a few milliamps. Never measured it but it was enough prevent my 15 watt solar panel from keeping the battery charged. I would remove the main fuse in storage.

An inverter on and idling will draw almost 1% of rated power.

[brulaz]

With mine, as long as the inverter power switch is off, no power is drawn.

[westend]

If the inverter has a switch that eliminates any 12V draw, you can install a battery disconnect anywhere you want. Typical inverters behave like that and there are some that automatically do that but are in standby until 120V power is needed.

For your application where assumed storage disconnect is needed, install the disconnect close to the battery. If you choose a master disconnect switch with the right terminals, you can move the CO2 alarm and the slide to the load side of that switch. The only circuit that needs connection to the battery beyond a disconnect switch is the emergency break-away system for braking. Leave that directly connected to the positive polarity terminal of the battery. The reasoning is that even if you hook up and drive away with a battery disconnect switch in the "off" position, your emergency braking system will still operate.