Battery seems to go dead too fast

[brianp11]

Hi there, new to the forum. Just picked up our 2014 TT a few weeks back and am trying to get used to it in the driveway before our camping season starts. I seem to be having an issue with the battery. I have the RV plugged in to shore power so I'm assuming it's charging the battery, but when I disconnect from the house, and try running a few things, the battery is dead in a very short time (3-4 hours of leaving lights and radio on). I've taken the battery in to a shop and had them test it, and it shows as a good battery. Any suggestions on what to look for? Thanks!

[PARAPTOR]

Make sure if you have a battery disconnect switch that it is the "ON" position. Battery will not charge off the converter when connected to shore power and that switch is off

ADDED:remember when your connected to shore power your converter is the main source of 12 VDC power to your rig, battery disconnect in "ON" position enables the converter to also charge the battery

[brianp11]

I'll check that tonight, but one thing that makes me think that's not the problem is that the battery showed as fully charged when the shop tested it.

[PARAPTOR]

I'll check that tonight, but one thing that makes me think that's not the problem is that the battery showed as fully charged when the shop tested it.

Did they put a load test on the battery when they checked it? or just check the voltage?

[brianp11]

Both, as far as I can tell. I'll try and upload a pic of the printout from the battery test.

[brianp11]

Here's a pic of the printout

[PARAPTOR]

Just came in from raptor

Checked some current draws on battery ( have not checked accuracy of meter yet)

normal (nothing on) drain .44 Amp (Detectors (2), generator fuel gauge, radio memory etc)

Single halogen light .36 Amp
921 LED Halogen replacement .13 Amp
Radio low volume 2.0 Amp
Radio low mid volume 3.4 Amp
Raptor has a 700 Watt Amp did not turn it up, just do that to get leaves and acorns off the roof :facepalm:

Furnace would draw alot, since you said only had lights (#?) and radio on you should be able to estimate you amp drain based on the numbers above
will look at your slip

[chuckster57]

That ticket shows voltage. MCA is cranking amps, I don't think that's the same as a load test. Cranking amps are associated with "starter" batteries like in cars/trucks. Amp hours is the key to "deep cycle" batteries, most common for RV and marine.

Is your battery a deep cycle battery?

[sourdough]

Sounds like either a converter issue or a battery issue; I'm betting on battery.

[PARAPTOR]

That ticket shows voltage. MCA is cranking amps, I don't think that's the same as a load test. Cranking amps are associated with "starter" batteries like in cars/trucks. Amp hours is the key to "deep cycle" batteries, most common for RV and marine.

Is your battery a deep cycle battery?

Thanks for chiming in I was reviewing his battery test slip and agree it loads like a cranking amps test no sure how that equates to an amp hour drain??

My wild guess he was drawing around 4 to 4.5 amps during the period he stated. Since I do not dry camp have no feel for how long these batteries last and what people use in the term of amp hours. Think he only has one battery which is not a good setup to run off the batteries. I think I saw somewhere that a car battery was about 50 Amp Hours. given that number he would of had 10 hours, if I recall he said he used it for 4 or 5 hours??

Maybe someone who boon docks can give us an idea about normal amp hour drains as well as how long they last

If CC has no sewer, pedestal or running water I am not there :banghead:

ADDED: do not think it was a deep cycle 800+ cranking amps

[brianp11]

I just checked - my battery disconnect switch is indeed set to "ON". And yes, the battery is a deep cycle marine/rv battery.

When I ran the battery dead I had about 8 of the ceiling lights on, and the radio on all three speaker locations.

[JRTJH]

The "average" 921 incandescent bulb draws about 1.4 amps, so having 8 ceiling lights on (each ceiling fixture has 2 bulbs) would put (16 x 1.4= 22.4)roughly a 22-23 amp draw on your battery. The stereo, depending on how loud you had the volume, could draw anywhere from 5 amps to around 15 amps. So, you're looking at somewhere around 27+ amps "continuous" draw. That doesn't include any of the "phantom draw sources", so you can "maybe average it all" and make a guess of 27-30 amps of power use.

So, if your battery specs at 160 amp hours, it would provide that 27 amps for about 5.9 hours before it was "dead". (160AH / 27 amps = 5.92 hours) and that's with a fully charged battery under "ideal" conditions.

Different batteries provide significantly different power capacity and different battery sizes complicate the issue. A GP24 battery won't provide as much power as a GP27 battery and a GP31 size will provide significantly more power capacity than a GP24. Then you need to consider the "quality" of the battery. Some are built to provide a lot more power than a "lighter duty" deep cycle battery.

My guess is that if your battery is "dealer provided at purchase" it's probably not a "top of the line" battery and it's probably a GP27 (mid size) battery.

So, all of that said, getting 4 or 5 hours with eight "dual bulb ceiling fixtures and the radio driving 6 speakers on a "cheap, mid sized deep cycle battery" is probably asking for all it could give you. It'll take your WFCO converter at least several hours to recharge to full capacity.

One of the best "mods" you can do for your trailer would be to convert to LED lighting and install a dual battery system. Do some reading on the forum about battery systems, both 12 volt and 6 volt. The information is readily available and knowing your options will help you make the right choices for your particular needs.

[brianp11]

Just to eliminate one potential problem, is there a way I can check to make sure the converter is charging the battery? For instance, if I run the battery dead again, and then plug in to shore power, can I test the charging system?


Sent from my iPhone using Tapatalk

[chuckster57]

Easy to check. With the trailer plugged into shore power, measure voltage at battery posts. If charger is working you should get 13+ VDC.

[canesfan]

One other thing, you said it is a 2014. Did the battery come with it and is the same age? Batteries only last X amount of years generally. if it's 3 years old it might be time for a new, larger battery.

[JRTJH]

Just to eliminate one potential problem, is there a way I can check to make sure the converter is charging the battery? For instance, if I run the battery dead again, and then plug in to shore power, can I test the charging system?

Yes, there is a procedure to check the converter output which will determine if voltage is getting to the battery. According to WFCO, disconnect the battery terminals and with the trailer plugged into shore power, there should be 13.6 volts across the battery cable terminals. If so, that power is being produced by the converter and the output is correct. If there is no voltage across the (disconnected) battery cable terminals, check the reverse polarity fuses on the converter and replace if necessary. If there is still no output or if the fuses are good, then the converter is defective and needs to be replaced.

You can download the WFCO troubleshooting guide at: http://wfcoelectronics.com/wp-content/uploads/2017/01/8900-Operators-Manual.pdf

The output test I described above is found on page 5 of the download listed above.

I believe that if you're getting 13.6 volts to the battery cable terminals (as tested above) either you have a bad battery, a "worn out" battery or you're expecting "too much" from the battery bank you have installed. My guess is that it's very likely to be a combination of an "old battery" and expectations beyond the capacity of your battery.

[brianp11]

Thanks for all your input! I'll take some time this weekend and work on your suggestions - much appreciated!