Dead battery issue in new trailer, typical current draw?

[antrubano1]

New 24 Micro Minnie 2108FBS

Battery will not hold a charge for more than 2-3 days. I confirmed my truck is charging it while connected, the converter is charging with shore power connected and the battery switch is turned off while parked.

Everything inside works as it should, nothing is left on. I'm aware the slide, solar controller and tongue jack still receive power with battery switch off.

Parked, turned off battery switch, confirmed jack light is off and 3 days later, the battery is completely dead. Wont even light the interior. Thought I left something on. I double checked everything, charged battery and it was dead again a few days later.

Dealer says there's nothing wrong, it's fully charged from my truck upon arrival. Battery tested good, I also had it tested locally where it again tested good. Dealer says I can bring it back, but they're almost 2 hours each way, if it's something common/simple I'm hoping to avoid the back and forth.

I fully charged/reinstalled the battery, connected my multi meter inline and measured current draw.

Battery switch on, there's a 300 milliamp draw (fridge and lights off, radio memory and LP detector on)

Battery switch off there is a 100 milliamp draw. This sounds right since it's powering the solar controller after dark.

There is zero reason for this to be dead in such a short time. I'm thinking about disconnecting the solar controller tomorrow to see if it holds a charge.

Has anyone had a similar issue with these?

[Morich]

There are a number of posts and problems on this trailer group. Try looking under the front frame, kind of like under the propane tanks?
There are likely a bunch of different breakers, fuses, etc. with lots of unnamed wires. That whole idea is in a bad space and I feel poorly designed as it has little chance of worked for very long!
If you have had any rain in your area, take a look at how much water splash goes on these connections and how little space there is between the connections and the frame which is ground!
It's like spraying water in your breaker box every time you hit a puddle and it can get wet! DUH!
When it's wet enough times, you get tripped breakers or corrosion that makes bad connections or possibly random stray paths to ground on the frame!

A recent post here for more info and pictures:
https://www.winnieowners.com/forums/...ng-367015.html

A second point? You may also need to leave the battery disconnect switch on when plugged in as it may be cutting the path from your converter/charger to the batteries!
That may be part if not getting charged fully and also a "slow leak" of power to ground?

[antrubano1]

I did check the horribly executed breaker/wiring situation in the front and found no obvious issues but didn't consider an occasional short to ground. I'm going to hook the meter back up tomorrow and do some wire wiggling/tugging to see.

[Morich]

Those links in the other posts may also have some info on getting drawings of what they installed?
Possibly some ideas of what others have done to try to protect it better?

[powercat_ras]

Chances are the dealer gave you a cheap group 24 RV/Marine battery, perhaps not even a new one. It could be as little as 50 amp-hours. With battery on when parked without any lights on, it is draining 8 amp-hours per day, so you should be able to go at least 5 days from full charge to 20% charge.

If you unit has a solar panel and is parked outdoors where it can get 6 hours of sun a day it should be making up the 8 amp hours per day when the sun is shining.

[antrubano1]

Originally Posted by powercat_ras

Chances are the dealer gave you a cheap group 24 RV/Marine battery, perhaps not even a new one. It could be as little as 50 amp-hours. With battery on when parked without any lights on, it is draining 8 amp-hours per day, so you should be able to go at least 5 days from full charge to 20% charge.

If you unit has a solar panel and is parked outdoors where it can get 6 hours of sun a day it should be making up the 8 amp hours per day when the sun is shining.

It has an 89AH Interstate group24 in it. Date sticker is 06/24.

It has 200 watts of solar and is in full south Florida sun for 12-14 hours per day.

Battery tests good but is dead within 2-3 days. That’s why I’m confused.

I actually have a 230AH Lithium for it but I was trying to make sure there wasn’t a problem in the trailer itself before installing it. Dealer has been frustratingly less than helpful.

[Morich]

You mentioned a point in your first post and it may be part of the confusing draw down going so fast.
You said this:
the converter is charging with shore power connected and the battery switch is turned off while parked.

Is this plugged in while stored but with the battery switch turned off? We don't get the best wiring diagrams for trailers, but in the motorized group, the battery disconnect switch also cuts off the path for charging the batteries, NOT just the drains for lights, etc.!

I may be reading what you meant wrong but if you think you are getting charge to the batteries when plugged in, that can be a problem if the charge is actually cut off from the batteries by the cutoff switch!
Is the solar output getting to the batteries or is it also cut off by the switch?
Maybe do a check if that is true on your RV?

[antrubano1]

Originally Posted by Morich

You mentioned a point in your first post and it may be part of the confusing draw down going so fast.
You said this:
the converter is charging with shore power connected and the battery switch is turned off while parked.

Is this plugged in while stored but with the battery switch turned off? We don't get the best wiring diagrams for trailers, but in the motorized group, the battery disconnect switch also cuts off the path for charging the batteries, NOT just the drains for lights, etc.!

I may be reading what you meant wrong but if you think you are getting charge to the batteries when plugged in, that can be a problem if the charge is actually cut off from the batteries by the cutoff switch!
Is the solar output getting to the batteries or is it also cut off by the switch?
Maybe do a check if that is true on your RV?

I apologize if my original post wasn’t clear.

I was saying that it’s charging correctly while connected to shore power and while it’s connected to tow vehicle.

When it’s parked (and draining) it is not connected to shore power and the battery switch is off.

I confirmed by measuring, the battery does charge by shore, tow vehicle and solar while the battery switch is off.

I measured current draw with the battery switch off and it’s drawing 100 milliamps, seems pretty normal. That’s about 2 ah per day of draw, but it should take months to kill the battery, it’s draining to zero in about 3 days.

I’m wondering if there’s an occasional draw or short to ground somewhere in the jack, solar controller or slide controller while the switch is off.

I’m automotive electrical competent by trade and I’ve been thoroughly through this trailer unable to find a problem, neither has the dealer.

[Morich]

Ok, Clear enough!
Sometimes this communications stuff is hard when we are not looking right at the same thing! And you know how much it hurts to not have any drawings to look at!
No need to tell you how hard it gets to fight the intermittent stuff!
Current flow has never been one of my favs for looking for trouble but if you can get enough ideas of which wire in the bunch goes where, possible to cut the chase by finding which wire has the draw?

[antrubano1]

Spent some time with it. Fully charged the battery 2 days ago. Reinstalled it yesterday morning. It was down to 12.84 volts by the end of the day, this morning it was 12.28 and after work today it was 11.21 volts. Put the meter back on the battery, it’s still drawing around 110 milliamps with the battery switch off. It was also in full sun all day but the highest the voltage out of the solar panel got was 11 volts and it doesn’t appear to have charged the battery. (I even measured at the connector on the roof) I entirely disconnected the solar controller and jack, still draws 100 milliamps. Something is killing this battery in 2 days and there’s hardly a draw whenever I measure it.

[bigb]

Why don't you start by disconnecting everything, charge it up then wait a couple days while testing every few hours to first verify the battery itself in not the problem. Then connect one thing at a time and repeat. At least this way you will find out for sure if it is in the RV electrical system, the jack, the solar or just a bad battery. Once you find which branch it's in (if it's not the battery itself) you can repeat the procedure with that branch.
In electrical troubleshooting, finding out what it isn't can lead you to what it is.

I don't know what method or tool was used that tested your battery as good but lead acid battery testing can be deceptive and is not always 100% reliable, especially if the battery was not tested in the same manner in which it is used, for instance putting a starting load on a deep cycle battery with a load type tester.

The common capacity type hand held tester that most places use now has a certain percentage of an incorrect result rate per 100 batteries tested, I don't recall the exact percentage but the tool is preferred because of it's simplicity and safety and does well enough in the majority of cases to be considered sufficient, however they are intended for testing starting batteries.

A true test of a deep cycle battery involves a load over time per it's C rate. There are fancy machines to do this but you can just make up a load equal to the C rate and time it to get close enough results to see if it's in the ball park. You can also tell a lot with a good old fashioned hydrometer.

[Morich]

Two small points to keep aware of as you go along? One is that the lead acid type battery will only hold around 12.8, so the higher is not a real indicator as the battery is not stable yet.
Then if not working it fully, there will be safety items left as drains, even when we turn the disconnect off. So at least part of the 110 Mill is normal drain unless you did more to remove it.
Check for a small green LED on some of the detectors (CO and propane) to see if they are still on?

Part of this that makes current flow tests unreliable is where I often move to resistance and voltage testing as the resistance will show me better what drains are left. It does still require knowing what is on the other end of the wire like motors, etc. but I like the more reliable numbers. Current changes as the voltage changes but the resistance will be more constant levels.

[bigb]

Given the facts (if accurate) and the likelihood of different scenarios I'd put money on the battery being faulty. Another clue is when charging from dead with an external charger is to see how long it takes at the average charge rate to reach full. If it reaches full long before it should when multiplying the average charge rate X hours is is on it's way out. (You would need to monitor the charge rate as it will change with time, is it dropping quickly indicating not much capacity?)

[bigb]

Reading through the thread again one thing I don't see, unless I missed it, is if you tested the draw after dark?

[antrubano1]

Originally Posted by bigb

Reading through the thread again one thing I don't see, unless I missed it, is if you tested the draw after dark?

I checked draw at night and in the middle of the day, it’s identical. 100-110 milliamps at all times with everything off and the battery switch off.

At 2pm in South Florida sun, I’m getting 11.5v from the panel and no charging. At night it measures 1v from the panel.

If I unhook the solar controller, draw drops from 110 to 100 milliamps which sounds right.

Only thing still connected at that point is the slide controller.

Each time I’ve charged the battery, it’s been 8 hours at 10 amps. Even if that’s not 100%, it’s enough that the battery shouldn’t be dead after 2 days with the battery switch off.

It’s going back to the dealer this week. It’s only a couple weeks old. I just know it’s going to be back and forth with no problems found.

[bigb]

Originally Posted by antrubano1

I checked draw at night and in the middle of the day, it’s identical. 100-110 milliamps at all times with everything off and the battery switch off.

At 2pm in South Florida sun, I’m getting 11.5v from the panel and no charging. At night it measures 1v from the panel.

If I unhook the solar controller, draw drops from 110 to 100 milliamps which sounds right.

Only thing still connected at that point is the slide controller.

Each time I’ve charged the battery, it’s been 8 hours at 10 amps. Even if that’s not 100%, it’s enough that the battery shouldn’t be dead after 2 days with the battery switch off.

It’s going back to the dealer this week. It’s only a couple weeks old. I just know it’s going to be back and forth with no problems found.

I don't have a lot of faith in RV techs testing batteries, at least you could charge it up and disconnect it and see if it still discharges quickly. The RV place is likely reluctant to replace things at their expense as well.