Hidden drain on batteries

[oregonrambler1]

Went to start up the RV and generator, it's been sitting about a month since last trip. There was a muted beep beep, followed the sound and it was coming from the floor level gas detector. The house batteries were cut off at the switch. When I reconnected the house batteries the beep stopped. So, ok, the detector is hard wired with no internal battery backup. When I went to start the RV, the starter battery was way way low. I had to boost the power with the house batteries. Now my question is are the safety detectors that are hard wired in the coach run on both battery systems? Is that why the beeping stopped when I engaged the house batteries? I assumed that when the house batteries were cut off nothing would drain power from them (and they did have a very good charge) but the starter battery didn't have enough juice to start the engine. So do the detectors switch themselves from one system to the other when one is deficient and then start beeping because the power drain pushed the battery to low?

[Bethers]

Your engine battery shouldn't be used for anything in the coach when you disconnect the coach batteries. However, strange things seem to be done on various rigs. I know Pooker has had a problem from day one on hers (and she purchased new) and now disconnects the engine battery, also. (After no one could figure out what was doing it). Some have weird radios that don't shut off and drain. I'm lucky - don't have a problem there. Unless you can get someone to run some type of diagnostic to figure that out, you might want to either run a trickle charger on the engine battery, or disconnect it also.

[mitch5252]

When you've disconnected or shut off the battery, put a cheap amp meter on it. See if there is any drain. I had to buy one when I was up in Alaska and because I didn't know quite what I was doing, I think I blew the thing up. I have a electric genius friend coming to visit this weekend, so I plan to ask him if I really did blow up the meter, and if so, how to do it properly. The meter was only like $18 (it was a multi-meter that had a 10A measurement, something my good multi-meter did not have).

[WickedLady]

Mitch: Most likely you just blew the fuse.

[ellenw]

arrgghh! I can see I'm going to have to get an Electrical Engineering degree!

[BirdbyBird]

There can be hidden drains on the engine battery. It took me two years and a very patient RV repair man to find the "Fuse" that was shorting out and draining my battery after only 2 days.....It was a pain. He found a 30 amp fuse for an electric drivers seat ...that my coach didn't even have installed.... Someone with the patience to go fuse by fuse could probable find the where the drain is coming from.....