Battery drain

[riverplace]

I’ve had my 2006 17B sitting out this summer, after using it in May. In august, I noticed the battery was too weak to turn on lights. After plugging in to ac, it charged up and was good for a month. Now it’s weak again. No corrosion on terminals. When I connect the negative, there are sparks, so something must be drawing power? Everything is turned off. Is there a way to check at fuse box if anything is drawing? Battery is only 3 years old.
Thanks!

[davidmurphy02]

Does your trailer have a battery disconnect switch, and do you keep it set to "off" when not using the trailer? How have the batteries performed in the past? If the batteries are fully discharged - which it sounds like is the case if your lights won't even operate - that can negatively impact their ability to hold a charge in the future. Even though they are called "deep cycle" batteries, lead acid batteries are recommended to never be allowed to discharge below 50%, if that happens several times they can lose their ability to hold a charge regardless of their age.

[Iowa Dave]

Have you kept up on putting water in the battery cells? That can affect the ability to hold a charge and the lifespan. If you’re not
Plugged in to shore power there are “phantom draws” as noted that will draw your battery down . Also, sadly, sometimes three years is all you get out of a battery, especially if it’s bounced around a lot. That’s been my experience. You did not mention the brand and whether or not it’s a battery with a “declining”
Warranty. Might be time for a new one. You can take a charged battery to most any auto parts store and they can check it for its health and whether or not it has any weak cells.
Iowa Dave

[riverplace]

There is no battery disconnect that I have ever known about. Normally, I am able to store the trailer throughout the summer without battery draining. I did do some non hookup camping last fall and this spring, but wasn’t aware of battery being drained too low. Mostly use for water pump. What do you think about the sparks when I connect the negative terminal?

[riverplace]

It’s a Napa sealed gel marine battery, so no water to add, and I haven’t kept it plugged in to “shore “ power. I took it in to Napa last fall and they said it was good. I kept it on a trickle charger over the winter, usually I bring it indoors and do that, but it’s so heavy, the Napa clerk said I could keep on trailer as long as on trickle charger. I’d like to get six volt, but there’s no room for second battery on the back of trailer.

[Iowa Dave]

Hmmmm doesn’t seem promising for a long happy battery life. Could get it checked again.
Iowa Dave

[alanmalk]

Originally Posted by riverplace

...
Is there a way to check at fuse box if anything is drawing? Battery is only 3 years old.
Thanks!

Yes, but somewhat tedious.

Using your trusty multi-meter (You do have a multi-meter? Especially since you are a camper...), and a helper: Disconnect one of the main battery connections - Pos or Neg, doesn't matter - and use the multi-meter on Amps mode. Insert the meter between the disconnected wire and the battery terminal. You should see a reading that corresponds to the sparks. Hopefully the amperage is not higher than the rating of the meter, but we won't know until you try. Now, have the helper pull the DC fuses one at a time until the amperage goes to near zero. You have now isolated the branch that is the culprit. At that point check everything on that branch one at a time.

If pulling all of the fuses fails to bring the amperage down to near zero then perhaps something outside the normal fuse box is the problem. I would hazard a guess that things like the emergency brake system, or the propane detector are not on the fuses. Don't know this for certain. Double check that your emergency brake switch pin is in the proper position - not partially pulled.

This is really detective work and requires your hands-on input. In other words, not something easily diagnosed over the phone (or web).