Battery Drain Question

[RamsFan1]

My trailer came with an Exide group 24 battery when we purchased it new 09/2013.
The past 2 winters I put it on a trickle charger in my garage.
We camped the weekend of 03/21 and had it plugged in to my 30amp at the house before taking it to storage. The battery showed fully charged in the trailer when I left it.
I went to check on it and the battery showed 1/3 full today.
I did accidentally run it dead last summer when I left the pass thru LED lights on, but had nothing on today.
I realize there is some parasitic drain (I don't have a battery kill switch) but a week later having the battery show 1/3 full seems like a problem after one week ( it has been in the 70's temp-wise here).
We do some dry camping and I don't want to have an issue later this summer.
Is there anything specific I should check on the battery or should I just get a new one?
I am leaning to getting a single group 27. My a frame is not set up to fit 2 batteries in parallel.
Any suggestions would be helpful!

[boondocking]

The parasitic draw is more than likely around .3 amp (propane detector, CO detector etc). That would amount to 7.2 ah per day x 7 days equals 50 ah. The group 24 battery would be around 80 ah, so that would account for the battery being 1/3 full after one week.

[VinceU]

Originally Posted by boondocking

The parasitic draw is more than likely around .3 amp (propane detector, CO detector etc). That would amount to 7.2 ah per day x 7 days equals 50 ah. The group 24 battery would be around 80 ah, so that would account for the battery being 1/3 full after one week.

Agree with this post and add the following: whenever a battery is allowed to fully discharge, or drop to 1/3 permanent damage will result to plates and will resist accepting full charging, prevent it in other words. If possible never allow the battery to discharge more than 50% of capacity. This number is measured with good voltmeter or hydrometer(best). For info a singe size 24 or 27 will not work for a weekend without a generator.

[RamsFan1]

Thank you both for the response.
That helps.

[KyDan]

I totally agree on the subtle drain(s) on your battery(s) if you don't
have a disconnect. A battery disconnect should be standard equipment
on ALL trailers and motor homes!! It's the first thing I add when I'm making
a new rig ours...

I also agree with the part about trying not to drain batteries below 50% and
the fact it's hard on them to fully discharge them but I do think the danger
of full discharge is sometimes a little overblown.

Just from my personal experience. Last trailer came with plain old "marine/
crank/deep cycle" group 24 12v. I bought another 6 months later so we
had 2 in parallel. We used and slightly abused those batteries for 5 seasons.
We occasionally watch TV on battery power using a little cigarette socket
inverter. We occasionally watch DVDs this way as well. We rarely ran the
batteries all the way down but it did happen. We ran them down to where the
furnace sounded lethargic and the lights were notably dim on a couple
occasions. We got 5 seasons out of them.
I have the luxury of parking my trailer at home. I always keep the battery
switch OFF at home and the batteries connected to a Battery tender Jr.
Did I mention I got 5 seasons out of them?? IF you can get power to your
rig a battery tender will add months or even years to your batteries!
(I just replaced the battery in my motorcycle. It was in there for 4 full
seasons. "Normal" is about 2 years. Yes it's on a tender all winter...)

IF you run your battery dead it's bad. I'm not saying it's not but just give
it a full charge ASAP and keep an eye on the electrolite level. You'll probably
be OK. Just don't make a habit of it.

Happy Trails!

[Herk7769]

FYI:

"Fully Charged" always makes my eyes rise as most folks don't really know.

Unless you have removed the battery from the camper for 24 hours and left it undisturbed (rested); THEN taken a digital voltage or hydrometer reading indicating 100% capacity according to the below chart (brown); you have no idea if the battery is charged to capacity.

If you are using the "idiot lights" to determine this, remember that when you use the "battery" button, the top light only indicates the camper (not necessarily the battery) is seeing charging voltage. If both current limiters between the converter and the battery are closed, the lights indicate the battery should be charging.

If you remove the AC power cord, and let the camper sit for 24 hours with everything you can turn off "off"; the lights should reflect whether the battery is charged above 50% capacity (3 lights) or above 90% capacity (4 lights).