12V battery replacement.

Knauby · 10-21-2016, 12:01 PM

Thinking ahead for next season as I just winterized. I am pretty sure I ruined my wet cell deep cycle battery this season by completely (or really close to it) discharging it on more than one occasion. I am getting a reading of only 10.4 volts and it drops to less than 8.5 volts under any load. So as for a replacement I was seriously considering an AGM battery but have read that they are prone to "overcharging". My concern is I don't know if the onboard battery charger is a "dumb" charger or a "smart" charger that actually monitors battery while charging.

My electrical knowledge is limited so maybe I'm not making any sense at all here, IDK.

Any guidance is appreciated.

**Mustang65** · 10-21-2016, 12:04 PM

What do you have TT? year?
Is there a reason that you are looking at an AGM battery? Will you be dry-camping? How long are your outings? On Shore power? Will the battery be outside in a battery box or inside?

Thanks

Don

Knauby · 10-21-2016, 12:16 PM

I have a 2016 Northpoint 5th wheel camper. I very rarely dry camp and while using the camper we usually have shore power. Unfortunately the camper sits sometimes and the battery is not being charged for weeks at a time.

My camper has the wonderful GroundControl leveling system that is extremely sensitive to battery voltage. (extremely!!!!)

My thought was going with an AGM battery I would have less discharge while not in use there for have a stronger battery when I go to camp.

I am aware that the AGM battery was designed for vehicles prone to rough rides and going upside down (aircraft) but the slower discharge rate is why I am interested in them. My battery will be in a vented and appropriate compartment in the camper.

**Mustang65** · 10-21-2016, 12:21 PM

Does your fridge run off an inverter as some 5er ones do?
Don

Knauby · 10-21-2016, 12:30 PM

Quote:

Originally Posted by Mustang65

Does your fridge run off an inverter as some 5er ones do?
Don

No, I have the good old fashion 12v/propane fridge. I think the only Northpoint ever built with such an option!

mike837go · 10-21-2016, 12:32 PM

Quote:

Originally Posted by Knauby

I have a 2016 Northpoint 5th wheel camper. I very rarely dry camp and while using the camper we usually have shore power. Unfortunately the camper sits sometimes and the battery is not being charged for weeks at a time.

My camper has the wonderful GroundControl leveling system that is extremely sensitive to battery voltage. (extremely!!!!)

My thought was going with an AGM battery I would have less discharge while not in use there for have a stronger battery when I go to camp.

I am aware that the AGM battery was designed for vehicles prone to rough rides and going upside down (aircraft) but the slower discharge rate is why I am interested in them. My battery will be in a vented and appropriate compartment in the camper.

That situation will destroy a storage battery in short order (pun intended).

If you plan on leaving your RV unplugged and unattended for more 3 days, disconnect the battery. The parasitic loads (CO detector, controllers for the fridge, water heater, etc.) pull just a trickle.... Every. Single. Day.

An AGM battery will be just a waste of money. They are NOT any more energy dense than flooded cell and are more easily damaged from deep cycling.

Buy yourself a new deep cycle battery next year and disconnect it when leaving the RV unattended for more than a few days.

Knauby · 10-21-2016, 12:35 PM

I always use the battery disconnect switch while in storage. Do you think I need to physically disconnect the terminals. I was under the impression only brake break away and landing gear were powered before that disconnect.

mike837go · 10-21-2016, 12:51 PM

Quote:

Originally Posted by Knauby

I always use the battery disconnect switch while in storage. Do you think I need to physically disconnect the terminals. I was under the impression only brake break away and landing gear were powered before that disconnect.

If your RV is in a poorly supervised storage area, you might want to think about taking the battery home to prevent theft.

The CO detector BY LAW is not turned off by the battery disconnect switch. Does the landing gear system automatically make minor adjustments after the RV has been leveled? That'll eat quite a bit of power.

So, yeah. Unless you are going to recharge your battery every week, physically disconnecting it is required.

You may want to consider a separate switch that you KNOW disconnects the battery 100%.

**Mustang65** · 10-21-2016, 01:04 PM

I would install your own cutoff switch that will disconnect EVERYTHING on the battery. That way you are sure there is no power going anywhere.

As far as battery replacement... I would go with (2) T105 220Ah batteries or (2) T145 260Ah batteries for your replacements. I have the T145 batteries and I am totally happy with them. They are into year 4+ and going strong. The AGM will die just as fast at the flooded types if you drain them to low, except you will pay more for your next replacement.

Just a suggestion, you may want to look at a Renogy 100 or 200 watt SOLAR system for you TT, mount them on your roof and they will keep your battery(s) fully charged and not have to worry about disconnecting the battery. My TT is parked next to the house and since I went SOLAR (250 Watts) 4+ years ago, it is never plugged in to 110VAC, unless of course we want to use the AC.

Don

bankr63 · 10-21-2016, 01:05 PM

I might also suggest a "light" solar setup for you. I have a small 40W panel that I keep on the roof in storage (could be permanently mounted). This charges my battery while in storage, and I'm always showing 100% when I arrive to pick up the TT. You don't need much to keep things charged up in storage - $200ish to setup.

Knauby · 10-21-2016, 01:21 PM

The trailer is "wired for solar" from the factory but I have zero knowledge of how that would work. More research for me I guess. That price tag of $200 isn't that bad and would solve my problems. I get nervous about doing things to the trailer I know little about.

**Mustang65** · 10-21-2016, 02:42 PM

Quote:

Originally Posted by Knauby

More research for me I guess. That price tag of $200 isn't that bad and would solve my problems. I get nervous about doing things to the trailer I know little about.

Head over to the "RVing with SOLAR" Social group here on the forum. There is information on batteries, SOLAR panels, SOLAR Charge Controllers, comparisons, installations, step by step installations..

Adding SOLAR is easy, and it actually is fun... but let me forewarn you, once you get into SOLAR there is no stopping you

Here is a sample kit you can start with. The 30 amp SOLAR charge controller will allow you to add additional SOLAR panels in the future if you need to.

Don

You may also like: