Newbie with a dead battery

Trvl_Far · 07-24-2021, 10:15 AM

I have a Wildwood 171rbxl 2021, my first travel trailer. We have used it twice so far and are getting ready for our big trip out west in a few weeks. We expect to boondock a few nights and will be at a campground with no hook-ups for 8 nights. The times we camped previously we had shore power available so the battery was never an issue.
It was parked in my driveway for two weeks, refrigerator off,, and the battery was completely dead whenI I checked a few days ago. I know it drains slowly so I was not too concerned. I plugged it into my household and had shore power for almost 48 hours. I unplugged it and the battery read 4V! Yikes!
I bought a 120W solar panel with the idea of topping off the battery when possible. After leaving it connected all day yesterday the battery reads 4.2V.
Do I need a marine battery, which would be a shame since my battery is virtually brand new. I realize I should have used the battery disconnect when I parked it, but two days of shore power should have changed it, right?
One last thing. While parking I broke the safety brake cable (dumb mistake,I know). It may have tripped it. I don't know how to tell. Would the brakes be on continuously since? That may explain why the battery ran down so completely but not why it won't charge.
Go easy on me, I'm learning.
Thanks.

MtBiker · 07-24-2021, 11:23 AM

If the brake cable was pulled then the brakes were on and you have destroyed your battery. Dead, done. No chance to revive.
You need a new battery. A deep cycle battery, not a marine battery.
Your trailer likely came with a cheap group 24 battery. This is the smallest lowest Amp hour battery.
A simple choice would be a single group 31 deep cycle.

**bikendan** · 07-24-2021, 11:58 AM

Quote:

Originally Posted by Trvl_Far

I have a Wildwood 171rbxl 2021, my first travel trailer. We have used it twice so far and are getting ready for our big trip out west in a few weeks. We expect to boondock a few nights and will be at a campground with no hook-ups for 8 nights. The times we camped previously we had shore power available so the battery was never an issue.

It was parked in my driveway for two weeks, refrigerator off,, and the battery was completely dead whenI I checked a few days ago. I know it drains slowly so I was not too concerned. I plugged it into my household and had shore power for almost 48 hours. I unplugged it and the battery read 4V! Yikes!

I bought a 120W solar panel with the idea of topping off the battery when possible. After leaving it connected all day yesterday the battery reads 4.2V.

Do I need a marine battery, which would be a shame since my battery is virtually brand new. I realize I should have used the battery disconnect when I parked it, but two days of shore power should have changed it, right?

One last thing. While parking I broke the safety brake cable (dumb mistake,I know). It may have tripped it. I don't know how to tell. Would the brakes be on continuously since? That may explain why the battery ran down so completely but not why it won't charge.

Go easy on me, I'm learning.

Thanks.

As was said, you may have pulled the breakaway switch pin, which sends power to the brake magnets. If this happened, you may have damaged the brakes.
You probably already have a cheap 12v marine dual purpose battery. A marine battery is the last battery you should want, they are not true deep cycle batteries. Start with a pair of 6v golf cart batteries.
I would also invest in a 2000w inverter generator.

Trvl_Far · 07-26-2021, 02:39 PM

I found the pin and it was not pulled out. So that is not drained the battery. Any ideas?
The battery says DC 24-140, so it is supposed to be deep cycle.

RobbieH · 07-26-2021, 02:51 PM

Also check the water. Most people never think to check it. It is especially important if you have the unit plugged in while in storage, but yeah, check the water. Used distilled water to top it off.

tomkatb · 07-26-2021, 02:54 PM

If the dealer installed the battery it is not a deep cycle battery. A sticker does not make it so.

Your voltage readings are curious.

If you do not turn the disconnect off you will kill a battery in less than a week.

Not enough information.

Your 4 volt readings might be operator error. Dead voltmeter etc.

You should plug the rv into shore power and read the battery voltage. It will read the output of the converter(battery charger). Should be between 13 and 14.5 volts. Or the converter is toast, or disconnected. Fuse blown.

A fully charged battery should read 12.6 volts. A 50% charged battery reads 12.1 volts. Batteries just off the charger read residual values of more. You have to let the battery rest before checking its actual charge.

Trvl_Far · 07-26-2021, 04:08 PM

When connected to shore power the reading was just under 15, so it probably was 14.5. As soon as I unplugged the power, down to 2. I have an older volt meter and can't get precise readings but I am confident I am close.
It is one of those maintenance free batteries so I can't add water.
It is under warranty so I should be able to get a new one. But of course it wouldn't be a better model. But even a cheapo battery shouldn't go that dead, less than 3 months old, unless something particular is draining it, don't you think?
It is possible the refrigerator was left on when I parked it. Could that have done it?
Thanks again.

Chuck_S · 07-26-2021, 04:27 PM

If you have the Battery Killer(tm) (brand) 12v or inverter powered refrigerator the battery won't last 24 hours without shorepower unless you have several big batteries.

A small Group 24 battery like yours deep discharged to 4vDC is unlikely to be resuscitated. So called "Marine" batteries are typically "dual purpose" so they can start the boat engine and power some lights. They're not true deep cycle.

Lessons learned here include (1) always disconnecting the battery unless it's being used or charged and (2) always making sure the trailer brake break-sway switch is not used. I kicked the lanyard on mine once and it locked the brakes and would have drained the battery rapidly if I'd not noticed if.

A "proper" battery switch should sever all connections -- but you normally gotta install one of these switches yourself.

-- Chuck

PS: When looking for a new battery avoid any with a MCA (Cold Cranking Amps) rating -- these are starting or dual purpose batteries. Only difference between starting and dual-purpose is the label, they're starting batteries.

nayther · 07-26-2021, 04:29 PM

give that battery its last rites. There are so many parasitic losses in new RV's you cannot leave the battery connected. It may be possible to revive it using an analog battery charger (read OG charger). The digital chargers need to "see" close to 12 volts before they'll kick on. I've fooled a digital charger before by connecting it as well as the OG and it worked. Also if you have a desulfite setting you might try that. I'd buy a new battery and if you have a residential refrigerator with inverter you'll need a LOT more battery than one single 12v or even two 6v in series.

camaraderie · 07-27-2021, 02:23 PM

Quote:

Originally Posted by Trvl_Far

When connected to shore power the reading was just under 15, so it probably was 14.5. As soon as I unplugged the power, down to 2. I have an older volt meter and can't get precise readings but I am confident I am close.
It is one of those maintenance free batteries so I can't add water.
It is under warranty so I should be able to get a new one. But of course it wouldn't be a better model. But even a cheapo battery shouldn't go that dead, less than 3 months old, unless something particular is draining it, don't you think?
It is possible the refrigerator was left on when I parked it. Could that have done it?
Thanks again.

Once any battery is down that low it is likely dead forever...yours IS a true deep cycle battery made by Deka and the DC distinguishes it from DUAL PURPOSE DP's in their lineup. Neither matters as either would be dead. You cite any number of things that could have drained it but are you also sure your charging sources are making it TO the battery. Plugged into your converter and ON...you should read 14+ volts at the battery terminal. If you do then the battery is simply dead and you need to replace it.
Right now...it seems that you are going to be doing a lot of boondocking and with a SINGLE DC24 battery that STORES 75 amp hours you must be able to LIVE between charges on 38 amp hours AND then spend at least 6 hours recharging to avoid being fairly quickly ruined. Your camper is outfitted from the dealer to go PLUG IN camping. The battery will get you there and then power your 12V stuff while it is being continuously charged.
If you want to BOONDOCK ...you need more and larger batteries and a generator to charge them. Suggest group 27 or 31 pair to begin. You should also get a true battery monitor like the Victron to see how flat your batteries are and when you NEED to charge and when you are done charging. No voltmeter readings in use can tell you that.

A pair of group 27s or 31s will give you 100 to 110 amp hours of USABLE power before recharging. Good luck with it all.

rsdata · 07-27-2021, 02:39 PM

Quote:

When connected to shore power the reading was just under 15, so it probably was 14.5. As soon as I unplugged the power, down to 2. I have an older volt meter and can't get precise readings but I am confident I am close.

battery is TOAST, use it to offset a core charge on a new one

IF a battery is labeled CCA or MCA that stands for COLD or MARINE cranking amps it is NOT a true deep cycle battery, but rather a dual purpose battery... a little deep cycle a little cranking style.

Anytime a battery is drawn down to 10 volts or less and not immediately re-charged then it is permanently damaged and will never have the capacity it had when new...

Take a terminal off the battery when parking it for any length of time when not hooked to shore power.

Tundra 2014 · 07-27-2021, 05:12 PM

If you pull the brake pin, it will kill the battery in several days. I have done it. Unless you towed this way, probable did not hurt brakes. Only way to tell is pull it forward several feet. Or jack up 1 side and turn a wheel, if it turns OK. You also have other things that will pull down the battery over time, like the CO2 sensor, clock ect., these are not on the battery disconnect on most trailers. I suggest just disconnect the negative wire from the battery when not in use. On my smaller trailers where I did not have space or need more batteries, switched to a group 31 deep cycle. You may have to change to a larger battery box, but pick-up about 25% on battery power over the group 24's. They just last longer because I did not pull it down as far.

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