2008 Montana and rv battery care

[Cris]

Hi,
My husband and I are new to the rv world. We bought a 2008 Montana last summer. I burned through two brand new deep cycle batteries in one summer. This year we are going to use AGM battery. We only camp on weekends. Should I be unhooking the negative wire on the battery when we leave after the weekend is over? Should I unplug the electricity as well? Thank you In advance forw any guidance you can offer. We have been learning everything the hard way so far.
Cris

 

[TJ&LadyDi]

Welcome to RVF, @Cris; glad to have you join us here. Not sure how or why you are “burning through two brand new deep cycle batteries in one summer,” but here are some thoughts. Lead acid (including AGM) batteries need to be kept properly charged and not be drawn down below the 50% level. They also need to be kept properly “watered” (unless they are sealed AGMs).

“Properly charged” means both not allowing them to drop below 50% charge and not overcharging them or charging them too quickly. I presume your Montana has a built-in battery charger of some kind. It should be checked to see whether it is putting out the proper voltage/amperage. If it is under- or over-charging, battery life will suffer. Likewise, if you are routinely drawing your batteries down below 50% before recharging, battery life will suffer.

TJ

 

[Cris]

Thank you for your response. Okay I know this is going to sound ignorant.... So when you say “charge them”, that means I have to routinely charge them with my portable battery charger and use a battery tester periodically to make sure they are not over charging or undercharging?

 

[TJ&LadyDi]

Thank you for your response. Okay I know this is going to sound ignorant.... So when you say “charge them”, that means I have to routinely charge them with my portable battery charger and use a battery tester periodically to make sure they are not over charging or undercharging?

I don’t know what kind of charging system you have built into your Montana, so can’t answer that question definitively. That said, I’m pretty sure that you must have some kind of battery charging system in the RV that operates when you are plugged into shore power (120V). If that charger is not operating properly, your batteries will not be recharging, or will be overcharging.

You can get a pretty good idea of battery condition with a simple voltmeter (VOM). If your batteries are at or below 12.3V in a resting condition (nothing drawing power from them for a couple of hours), they are about 50% charged, at best. Here’s a link to what I think is a pretty good explanation of what we’re talking about.

How To Maintain Batteries - Deep Cycle Battery Store

THE BASICS ON BATTERIES *Important Items Highlighted/Colored First things first. A 12-volt battery is not a 12-volt battery. Twelve volts is just a nominal, convenient term used to distinguish one battery from another. A fully-charged 12-volt battery, allowed to “rest” for a few hours (or days) with

deepcyclebatterystore.com

TJ

 

[Kevin D Pem]

You didn't tell us how you camp, I assume you are camping unplugged.

Your not telling us if you get the rig plugged in the night you return home or if there is a lag in time before you plug in..

You also didn't let us know the weather you camp in. Believe it or not this minimum info is required for real answer. We should also know if you use a generator while camping.

 

[Cris]

Thank you both for this help.
I used to plug in the rv to the shore power at the beginning of camping season and leave the camper plugged in the entire camping season. I would also have the battey operating full time,, never disconnecting it, whether we were camping or not. So once , I did not turn off the refrigerator when we left at the end of the weekend. When we went back to camp two weeks later the battery was dead. I was told by a friend the battery wouldn’t be rechargeable at this point, so I didn’t even try.
So then I started to disconnect the negative wire from the battery when we were done camping , but I left it plugged into the shore power full-time . The second battery I bought kept draining quickly frim weekend to weekend and I had to keep charging it with my portable Charger.
So now I am thinking I need to unplug from the shore power at the campground and unhook the negative wire from the battery when we’re are done camping?
We don’t use a generator ,
We only camp during good weather meaning 50 degrees and above (approximately). We live in Ohio. I leave the camper at the campsite (which has shore power hookup) 100% of the time and we never move it .
Thank you all for this help. I appreciate it .

 

[Cris]

One more note... we just set up the camper today . I now have a brand new AGM Napa battery that I left the negative wire unhooked and I did not plug into the shorel power because we won’t be there to camp for another couple of weeks. Is this an okay decision?

 

[Kevin D Pem]

No ?. Keep plugged in and have the batteries connected. The converter is a 3 stage charger. It will keep the batteries maintained.

 

[Kevin D Pem]

That is unless the converter is bad.

 

[Cris]

Ok. Got it. Thank you Kevin. Is there a way I can check the converter to see if it’s in good working condition without taking the rv to the shop?