Disconnect battery when not using?

[rexmitchell]

We use out trailer every 3 weeks or so. Battery is always dead when we get back out even after 1-2 weeks. Replacing it since it’s going bad but wondering with the new if I should be disconnecting for these shorter storage times?

[rbpru]

My TT battery lasts about 3 days, if it is not plugged in to the 120v line.

Too many sneak circuits to keep it unplugged. I just
disconnect then negative battery lead. Simple enough.

[OleManOleCan]

salem wrote:
If I read it right, one of the posters said to disconnect the battery when connected to shore power. I've always been under the impression that the battery needed to be connected in order for the converter to keep it charged. In fact, that's what the dealer told me 15 years ago. Is there a different way of thinking now?

I'm the one who said it. Should have clarified.
I have a special situation.
Battery thieves are working our area. SO...
My batteries go inside my laundry room on a wooden shelf.
I have a trickle charger on them.
Before... I tried charging them every couple of weeks, but I would forget to re connect them...
SO... Now my batteries stay charged.
Yep... It's a hassle to take them outside and reconnect them.
BUT... The thieves have passed me by these days.

[Lwiddis]

For a couple bucks more, campigloo, ($23 actually) WindyNation sells a weatherproof controller that is a three stage controller (used with a 30 watt panel when Winnie is covered.)

[campigloo]

I bought a little solar panel from academy. It’s flexible and has a controller built in. Not sure about overall quality but it keeps my battery charged. When I’m rolling I store it in the cover over the propane tanks. $15 and so far it’s worked well.

[ktmrfs]

CavemanCharlie wrote:

ktmrfs wrote:
most likely the reason the battery is discharging so fast is that in most trailers the radio is on "standby" at all times, and will draw enough current to discharge a battery or even a pair in a few weeks. Also their is some much smaller drain from a 12V CO detector and/or 12V powered smoke detector.

So.... either disconnect the battery, install a disconnect switch, or pull the fuse for the radio when in storage.

Yeah,

Though I was thinking that 3 weeks is not very long to completely drain the battery. Your car has a radio and the car will go 3 weeks without the battery going dead.

Maybe it would be easier to install a switch in the radios power wire and the propane detector rather then putting a switch on the battery.

And, Maybe you have a short somewhere else and should trace it down.

actually I did install a switch on the standby power to my trailer radio. we seldom use the radio or tv so it is a nice solution for us.

Now car radios are an entirely different breed. Car makers know cars will sit for days/weeks and should start right up. So..... they have a smart power down sequence to minimize battery drain. Part of that sequence is to have a car radio system that doesn't draw constant standby power, but instead will store required radio info in non volitile memory (memory that doesn't require constant power) and then shut down completely. Powered up it reads the memory and knows what it's state and stored stuff was set to.

RV radios don't do that, at least the ones I have seen. the memory system needs constant power or it looses it's brains.

[CavemanCharlie]

ktmrfs wrote:
most likely the reason the battery is discharging so fast is that in most trailers the radio is on "standby" at all times, and will draw enough current to discharge a battery or even a pair in a few weeks. Also their is some much smaller drain from a 12V CO detector and/or 12V powered smoke detector.

So.... either disconnect the battery, install a disconnect switch, or pull the fuse for the radio when in storage.

Yeah,

Though I was thinking that 3 weeks is not very long to completely drain the battery. Your car has a radio and the car will go 3 weeks without the battery going dead.

Maybe it would be easier to install a switch in the radios power wire and the propane detector rather then putting a switch on the battery.

And, Maybe you have a short somewhere else and should trace it down.

[Lynnmor]

opnspaces wrote:


This is interesting and good to know about the red key failing. Where did you get yours? Is it from Harbor Freight?

I got them at AutoZone, most of that type are all about the same. What happens is that rain water gets inside and quickly corrodes the contacts. I always garage the trailer except when in use, so there was only a few rains that stopped the junk switches. Some are supposed to be water tight but don't believe it, just get a switch that boaters use.

[salem]

Openspaces: Thanks. Mine came with the trailer, but I don't recall if the dealer installed it or it came from the factory like that.

[wnjj]

opnspaces wrote:

rexmitchell wrote:
Thanks all. Until we can get a switch installed I’ll pull a cable.

One important thought on the switch. The switch is wired into the positive cable of the battery. Make sure that the emergency breakaway is isolated and NOT wired through the switch. This way the emergency brakes will still work if you make a mistake (we are all human after all) and tow with the disconnect open. The breakaway does not draw any battery power until it is activated. So it is safe to leave it connected.

x2 and a good reason to install a real switch instead of using a poor man's switch (pulling a cable off).

[ktmrfs]

most likely the reason the battery is discharging so fast is that in most trailers the radio is on "standby" at all times, and will draw enough current to discharge a battery or even a pair in a few weeks. Also their is some much smaller drain from a 12V CO detector and/or 12V powered smoke detector.

So.... either disconnect the battery, install a disconnect switch, or pull the fuse for the radio when in storage.

[opnspaces]

Lynnmor wrote:
And turn the battery off as soon as you are not using, towing or connected to power.

salem wrote:
If I read it right, one of the posters said to disconnect the battery when connected to shore power. I've always been under the impression that the battery needed to be connected in order for the converter to keep it charged. In fact, that's what the dealer told me 15 years ago. Is there a different way of thinking now?

You missed the word "or" but yes you are correct. In order for the battery to charge on shore power it still needs to be connected.

This is interesting and good to know about the red key failing. Where did you get yours? Is it from Harbor Freight?

[opnspaces]

rexmitchell wrote:
Thanks all. Until we can get a switch installed I’ll pull a cable.

One important thought on the switch. The switch is wired into the positive cable of the battery. Make sure that the emergency breakaway is isolated and NOT wired through the switch. This way the emergency brakes will still work if you make a mistake (we are all human after all) and tow with the disconnect open. The breakaway does not draw any battery power until it is activated. So it is safe to leave it connected.

[opnspaces]

^^ This shows how careful you have to be when posting. 🙂 Yes you guys are absolutely correct. When I was writing my post I was picturing disconnecting the battery after dropping the trailer off in storage as I do. But I neglected to say the storage part. Even though the OP isn't towing it home I fixed the original post.

[philh]

Boon Docker wrote:

opnspaces wrote:
Yes, as said above you need to disconnect the batteries when you leave to head home.

Not a good idea disconnecting until you get home. You need the battery connected for the break away switch while towing.

Depends on how it's wired. On mine, the breakaway switch is wired directly to the battery.