I got my trailer in July '16. I put new Trojan 6 volt batts in it. It sat down at the Dealer from Oct to early Jan in frigid temps and solar covered with snow while they fixed a bunch of stuff and remodeled some others. I went down to check on it around Christmas and make sure the solar panel was clear. Too late!! Batts were stone cold dead. And more than likely frozen. Talked to the service manager and said not to worry, he would replace the batts before I picked it up. When I picked it up the volt meter only said 12.0 volts. SM told me they don't come charged. I got it home and plugged it in. Looked at the batts and I honestly can't tell if they are new or not. A few days later I checked and the volt meter was flashing 13.5 and FULL. I unplugged shore power and shut off the solar and checked it each day. It fell a little more than .02 to .03 per day running nothing more than the gas sniffer. After 7 days the volt meter read 11.7. The weather has been cold, 10 t0 20 degrees, but I'd thought the batts would last longer than 7 days. I am suspicious I have been lied to. Like thawed out the old batts and put a charge in them?Thanks for your help......DJ

Date stamphttp://www.trojanbattery.com/pdf/TRJN_0522_date_code.pdf

Paracitic draw on RVs can kill a battery in a couple of weeks.

Solar is supposed to stay hooked up at all times. Everything else gets disconnected!

I'm not sure In totally understand the question. Can batteries go dead in a week? Sure the parasitic draws can easily kill batteries in week in cold weather.Did dealer replace batteries? Did you look at batteries for date stamp. Did they appear to be the original batteries? Did you ask dealer point blank if batteries had been replaced?If they were original batteries that had been left to freeze, I doubt they would have taken a charge.

I don't really understand exactly why you unplugged from shore power AND then disconnected your solar panels. Without any way to recharge, the batteries will lose power every day. You have parasitic draw on your batteries that is more than just your CO/LP detector, depending on what your trailer is equipped with. converter, inverter, the radio (even if turned off), TV, Blue Ray/DVD player (if they run on 12 volt) antennae booster, various monitors, USB chargers, etc. In very cold weather, the batteries will lose power even faster. Did you check the voltage about 4 hours AFTER you unplugged from shore power?While you were plugged in, the onboard charger could have been putting in the 13.5 voltage into the batteries, but that isn't necessarily what the batteries were holding. You need to let them set for a few hours and then take a reading to get a true indication of the voltage they are holding. Your math also doesn't add up. You said you started at 13.5 which was probably just the surface charge. You need to let it set for several hours or a day and THEN measure your starting voltage.. A fully charged battery should read at around 12.7 volts. But even if you started at 12.7 volts fully charged and lost .03 per day for 7 days, you should end up with 12.5 volts, which is an adequate 90% charge. Even if you got down to 11.7%, that is a 30% charge and not a death sentence for your batteries, but you should avoid going that low on a regular basis. If you lost 0.3 volts (rather than .03) per day, then you would be at 10.6 volts, which would be a fully depleted battery. But you said you checked it every day. Did the 2nd day's reading read at 13.2 and the third day read at 12.9? Those seem to be very high readings for a 12 volt battery.As others have said, check the date stamp on the batteries, although it is entirely possible since you bought this trailer new roughly 6 months ago that even new batteries might have a 2016 date stamp.

How long should a charge last? | Good Sam Community

24 Replies

harold1946
Explorer
Jan 31, 2017
Sam Spade wrote:
~DJ~ wrote:
I'm pretty sure the only draw is for the gas sniffer.

That likely isn't correct.

Almost every RV has a solenoid, control board or relay or two in things that you normally wouldn't think of that draws power all the time. Like a propane fridge, heat-A/C control board or even a master valve on the propane tank.

Sounds like you are finally starting to understand that not all RV systems are the same. CONGRATULATIONS :B
Almot
Explorer III
Jan 31, 2017
NinerBikes wrote:
Disconnect the ground wire from the trailer to the battery when not in use.

Yes.
Solar controller, however, should remain connected like I wrote earlier. I installed Big Baby breakers box by Midnite Solar, with buses and separate DC breakers for loads and controller, to take care of this. "Big Baby" is actually very compact, the size of a small loaf of bread.
NinerBikes
Explorer
Jan 31, 2017
Disconnect the ground wire from the trailer to the battery when not in use. End of parasitic drain. Always disconnect.
Sam_Spade
Explorer
Jan 31, 2017
~DJ~ wrote:
I'm pretty sure the only draw is for the gas sniffer.

That likely isn't correct.

Almost every RV has a solenoid, control board or relay or two in things that you normally wouldn't think of that draws power all the time. Like a propane fridge, heat-A/C control board or even a master valve on the propane tank.
Almot
Explorer III
Jan 31, 2017
Searching_Ut wrote:
With everything turned off that I can turn off, my 5er draws approximately .8 to 1 amp just sitting there, or 20 to 25 amp hours a day.

I wouldn't be surprised to see these numbers in a motorhome, but not in a trailer/5er in storage.

Here is what you can do to turn everything off: rewire the batteries properly. Off the factory they usually aren't. Batteries to Pos bus via battery fuse - ONE cable from Pos battery terminal to Pos bus. Loads to the same Pos bus via the Loads breaker to flip it off when you need. Then flip it off. Now you've really turned off everything you can.

Solar controller, if there is any, should be on its own cable to the same Pos bus, with its own breaker or fuse.

This is the safe and correct way to wire things - with a common Pos bus.

If there is no maintenance charge coming in, you can simply install a cut-off switch on the battery, to cut it off from everything. We are talking about storage, i.e. when you don't need fridge, propane sensor, big bright clock on the microwave or TV on standby.

Off the soap box :)
dewey02
Explorer II
Jan 31, 2017
~DJ~ wrote:
Sorry, I need to clarify a couple things. First, this was a test to see if they actually replaced the batteries as I couldn't tell from looking. That's why I disconnected shore power and solar. I also made a typo in the daily draw. Should be from .2 to .3 volts per day. I'm pretty sure the only draw is for the gas sniffer.

Thank you all for your responses. I think I will get it all charged back up and completely disconnect the batts and let them sit another week. Then pull the cover off the battery box (which is a real PITA) and do the specific gravity and look for those date codes that were posted. Problem there is they buy those batts by the truckload and would be very possible to have new batts with the June or July date code when I bought the trailer.

Sounds like a good plan. Let us know what you find. And good luck. I hope your batteries are in good shape. Those are pricey batteries to only last 1/2 year.
Harvey51
Explorer
Jan 31, 2017
Maybe you could take the batteries to the RV dealership, without saying where they came from, and have a load test done. This is usually free with a kind of understanding that you will buy new batteries if needed. In your case, if the batteries are shot you should be able to use the warranty. In my experience most batteries have at least a year of no questions asked replacement.

I have a house disconnect switch that shuts off all loads on the battery. That way I can go two winter months without charging. If your switch isolates the battery or you just disconnect a battery cable you probably will have to disconnect or switch off the solar panels from the controller because the battery controller will likely be very unhappy.

That advice about waiting several hours before trusting the voltage chart for state of charge is important. I lost a set of batteries not following that. If you want instant reading of % of full charge a battery monitor that counts amp hours in and out is necessary.

Thanks to the poster for the amp hour calculation on the propane alarm; nice to know how to calculate the discharge time for the battery.
Searching_Ut
Explorer
Jan 31, 2017
With everything turned off that I can turn off, my 5er draws approximately .8 to 1 amp just sitting there, or 20 to 25 amp hours a day. The only way you'll know for sure is to have a means to monitor what is going on, either through the use of a manual meter, or installing something like a Trimetric to monitor your batteries with.
Almot
Explorer III
Jan 30, 2017
wa8yxm wrote:
He said he got his traile in JULY,, now it's JAN, six months later

He made no mention of charging in the interim.

The batteries itself were 6 months old. After 7 days of no-charging (according to the OP) the voltage dropped from 13.5 to 11.7.

Doesn't sound normal to me. Check the water, check SG, check the manufacturing date (could be a problem since they often stamp some cryptic number instead of a date).
_DJ_1
Explorer II
Jan 30, 2017
Sorry, I need to clarify a couple things. First, this was a test to see if they actually replaced the batteries as I couldn't tell from looking. That's why I disconnected shore power and solar. I also made a typo in the daily draw. Should be from .2 to .3 volts per day. I'm pretty sure the only draw is for the gas sniffer.

Thank you all for your responses. I think I will get it all charged back up and completely disconnect the batts and let them sit another week. Then pull the cover off the battery box (which is a real PITA) and do the specific gravity and look for those date codes that were posted. Problem there is they buy those batts by the truckload and would be very possible to have new batts with the June or July date code when I bought the trailer.