battery Disconnect Switch Question

[dswiss]

I discovered that with the Battery disconnect switch in the 'off' position, the coach still draws 150mA of current from the Battery. The dealer told me that this is normal, and that to disconnect the battery completely, one has to install a separate disconnect.
Is this true?
And if so, what is the purpose of the disconnect switch?

[NO3putt]

If like our's, there are a couple of wires off the battery that do not go thru the disconnect, such as the steps, CO monitor so they are on all the time. Also for the engine, the computer has a small draw all the time. When stored, we just run a extension cord from te garage and keep 110 to the unit.

[JLeising]

On our 2012 Solera "S", the disconnect seems to cut power to most - but not all - "house" systems. The combination propane/CO monitor is, from what I can tell, turned off (in our MH) by the disconnect. The slideout still works with the disconnect switch turned off, as does the electric step. The in-dash radio (Magnadyne) also works with the switch "off" - but loses date, time and regional GPS settings if left "off" with the disconnect "off" for any period of time (??). Does not lose these settings when the disconnect switch is "on". If I were to guess, the small current you measured may be related to the in-dash radio. Unless activated, I doubt the slideout or the step draw any current.
There may well be other functions not disconnected by the switch which I haven't yet observed...

[JLeising]

Thinking more about this, 150 ma continuous seems too high. That much current (0.15 amps) would deplete 25 ampere-hours of battery capacity in a week. While I haven't measured my unit's "disconnect off" drain, I know my batteries will last (without notable discharge) over 6 weeks while stored.

[traveler2955]

Interestingly, many RVs do not come with disconnect switches. Obviously, the cost of adding a switch to thousands of RVs mean tens of thousands of added expenses. Similarly, an additional foot of wire in an automobile means huge costs during the life of a company.

Keeping the cost down might mean a consumer would purchase. That's why you pay gas on a price of X.99.

Certainly, an owner is remiss if he or she doesn’t consider the importance of a disconnect switch.

Switches do several things: they reduce the chance of a spark at the battery when disconnecting wires for any reason. As you know, hydrogen gas is given off in lead-acid batteries, and a spark will ignite hydrogen gas. Second, removing the entire house from the battery means you might be able to avoid a fire caused by improper wiring or a bad circuit. Both are safety considerations and piece of mind.

Unfortunately, some equipment must be connected directly to a battery. For example, many HAM radios and equipment do not function well when distributed through switched equipment, just like some monitor circuits which detail the charge of batteries. I’ve personal experiences with non-working HAM gear—mine, until a direct connection was made. All equipment, however, must be of correct wire, properly connected, and fused properly (fuse within 12” of any battery).

But, your losses might be due to monitors --not necessarily HAM equipment-- but wiring connected directly to the battery in addition to the switch lead. And you may use current even though you have disconnected your batteries but not the AC power. That converter used to charge your battery or power stuff might be feeding the leads to the battery-- where a circuit breaker at the converter would shut this down.

As a word of caution, installing a cut-out switch is a good thing (ONLY) if one chooses the proper rating on that switch, appropriate wiring and connectors.

Mike

[bclemens]

There are some things that wire straight to the BCC, not the disconnect. As has been mentioned, the slides are wired to the BCC. The regular underfloor slide probably doesn't draw much if anything, but the Schwintec slide has a "brain module" that may draw more.