Optima AGM Batteries

[Kevin H]

I want to be able to do an occasional evening off shore power when traveling. We do not plan to do multiple days off shore power. Am considering going from a single battery setup to a two battery. Currently, I have one 12v. Not sure it is even a deep cycle. It was the original in my 2013 Montana.

 

Our power needs would be minimal: LED lights, furnace (occasionally), pump, RV Fridge, slides and levelers. We do not have an inverter and do not plan on one at this time.

 

I have been looking at Optimas. They sound good. What I am not sure of is the battery groups. Should I go with the Group 31 Blue Top or the smaller capacity Group 34 Blue Top, or even the Group 27? I am not concerned with weight or space. Seems the 31 would be the better choice, but I am not a battery guy.

 

Or - shoud I go with a couple Sam's golf cart 6v.

 

I have an opportunity to buy 2 group 31s for $380.

 

Thoughts??

[dartmouth01]

It will depend on your battery tray. I had 2 group 29's so in my 5th wheels but couldn't transfer them to my travel trailer when I got that. Most battery that would fit was 2 Costco golf cart batts so I went with that. Either will work fine for a night. Heck, I was able to get 5 days on the 2 group 29's and that was with watching at least 1 movie on the TV a nightime, and stayed around 50% battery. That was without genny or solar.

 

I think most will say that the 2 golf cart Batts is a better choice since you can safely discharge them further, and they are more robust. But I think it will depend on the quality of each battery as well.

[Al F]

If you have the room, a pair of Sam's or Costco 6V golf cart batteries for less than $200.

 

If you can leave your furnace off during the night and just run it in the morning to take the chill off, you will be fine with just the single 12V battery. Just make sure it is a deep cycle, and not a Marine battery which is a combo starting and somewhat deep cycle battery.

 

Put a few blankets on the bed and you will be fine down to an inside temp of around 50* by 6am.

[Kirk W]

If you have the room, a pair of Sam's or Costco 6V golf cart batteries for less than $200.

That is what I'd do.

[Alie&Jim's Carrilite]

A cheaper AGM might be this http://www.exide.com/us/en/product-solutions/transportation/product/exide-megacycle-agm-200.aspx

Local farm stores here in North Dakota carry them.

[D&J]

When we bought our trailer new in 2003 I installed 2 Optima Blue Tops and I finally had to replace them in August of this year. I only had them out one time and that was to repair the battery tray and never had to clean a terminal. I replaced them with Blue Tops but the bigger ones they came out with I can't remember the number off hand. One thing to look at is their warranty, it states in red that if you buy them over the internet you will have no warranty from Optima. I bought mine from a local boat shop with a full warranty, they have a little differrent number because they are supplied through Interstate so I can go to any Interstate dealer and get them replaced if needed.

 

We have done a lot of boondocking over the years and could go for a few days without changing and overnight stays were no problem at all but we never ran the heat all night.

 

Denny

[Jimalberta]

For the type of usage you are describing......why spend the money on expensive AGMs? I agree with the above posts ....buy a couple for $200 or less...they will work just fine.

[Kevin H]

My reason for even considering the AGMs was the 'good' deal I could get. Having said that, it appears that 2 Sam's Club golf cart batteries for less than half the cost of the AGMs would be a 'gooder' deal.

 

I am going to do some playing and see exactly how my existing 12v will work. As Al suggested, that may prove to be enough in itself.

 

As usual, great feedback and expertise. Thanks.

[oldjohnt]

Kevin, when choosing batteries be they AGM (Optima or LIfeline of Fullriver etc) or Flooded Lead Acid, even for limited boondocking, the first consideration for me would be THE AMP HOUR ENERGY STORAGE RATING. AGM has the advantage of less venting worries and not having to monitor and add electrolyte, but are more expensive then lead acid. Even for limited 12 Volt boondocking, Id recommend at least in the neighborhood of 225 AMP HOURS TOTAL ENERGY STORAGE CAPACITY which for conventional flooded lead acid 6 volt golf cart batteries consists of a couple Trojan T-105 or equivalents wired in series for around $250 or less. I also highly recommend the use of true deep cycle batteries NOT semi deep cycle so called RV Marine Batteries like sold at Walmart. Also beware of some of the cheaper 6 volt deep cycle golf cart batteries which have far less then say 225 Amp Hours of storage capacity. Of course all is subject to room for keeping the batteries plus adequate venting if flooded lead acid are used. Way back in the days when I had but one battery if the furnace had to run a lot at night I had problems.

 

Your money your storage space your choice

 

John T

[Al F]

My reason for even considering the AGMs was the 'good' deal I could get. Having said that, it appears that 2 Sam's Club golf cart batteries for less than half the cost of the AGMs would be a 'gooder' deal.

 

I am going to do some playing and see exactly how my existing 12v will work. As Al suggested, that may prove to be enough in itself.

 

As usual, great feedback and expertise. Thanks.

Before you go out for your first overnight stay w/o shore power (i.e. dry camping) you should consider the following:

-- You mention you have a 2013 Montana. I would assume your existing battery is 4 or maybe even going on 5 years old.

-- It is probably a non-AGM battery, which may need to be checked every month or two to be sure the water level has not dropped down.

-- At your first chance look to see if the battery is sealed or has 6 removable caps to check the water level. If it has caps, be sure the water level is above the battery plates.

-- If you find the water level has dropped below the plates, you most likely need a new battery.

-- If you don't have a electric voltage multi meter like these for less than $20 from Walmart, you should buy one to check your battery. Amazon has them as well.

-- Once you have the multi meter, do the following:

-- While still connected to shore power check your battery voltage. The converter in the trailer should be keeping your 12V batteries at about 13.4V-13.6V.

-- Now disconnect your trailer from shore power

-- Check the battery voltage shortly after disconnecting from shore power. It should be around 12.6V-12.8V, maybe even a little higher.

-- Turn on all the lights in the trailer. Since you have LED lights they won't put a large load on the battery, like incandescent lights would.

-- Check the battery voltage, it shouldn't drop below about 12.3V-12.4V. If the battery is in very good condition it may even be 12.5-12.6V

-- if the voltage is below 12.3V with LED lights (are you sure all the bulbs are LED?) the battery may be in marginal condition.

-- Leaving your lights on, run your furnace while monitoring the battery voltage. The furnace fan puts an additional load on the battery. If the battery stays in the 12.2-12.3V range your battery should be in good condition. If it drops into the 11.7-11.9V range your battery may be marginal or bad.

-- You only need to run the furnace for a couple of minutes for the above check.

-- Now still being disconnected from shore power, leave all the LED lights on for an hour or two. In an hour or two, if your battery voltage drops into the 11.xx volt range your battery is probably in marginal condition and you could have problems dry camping overnight.

If there are voltage reading outside of what I have noted above, post the readings you get and I or someone else will help interpret your readings.

 

About the multi meter, you probably have a battery monitor panel in the trailer which registers 100%, 75%, etc. Don't depend on it to do the above checks. You really need to use a multi meter.

[Yarome]

If you have the room, a pair of Sam's or Costco 6V golf cart batteries for less than $200.

 

Put a few blankets on the bed and you will be fine down to an inside temp of around 50* by 6am.

 

That is what I'd do.

 

-- I would assume your existing battery is 4 or maybe even going on 5 years old.

 

Exactly. The Sams/Costo 6V GC's have been proved time and again to be about the best bang for your buck for the type of usage you're planning.. and as Al rightly pointed out.. it's probably getting about time for new batteries anyway.

 

Your existing 12v may not have the capacity it once had so your "playing around" with it might give you skewed results of what exactly is possible with a single 12v (be it a single 12v or dual 6v's).

 

I generally prefer a good heavy blanket and a propane catalytic heater as opposed to running my furnace in the temp range Al mentioned. That's a personal choice. I generally camp in rather secluded locations so the cycling on and off at night tends to wake me and I don't see the need to burn fuel and electricity to heat the underbelly of my rig. As John also pointed out, it's not difficult to find yourself in cooler temp's than you anticipated and overly discharge your battery/ies. A good blanket is cheap and 100% reliable.

[Al F]

We to use a catalytic heater and blankets and almost never run our propane furnace even when we are in a RV Park. We very very seldom use the catalytic heater while we sleep. We are comfortable under blankets until the bedroom temps get below the mid 40's.

 

If you do use a catalytic heater, be sure to follow the precautions about proper ventilation, i.e. window partly open with ceiling vent partly open.

[hemsteadc]

My reason for even considering the AGMs was the 'good' deal I could get. Having said that, it appears that 2 Sam's Club golf cart batteries for less than half the cost of the AGMs would be a 'gooder' deal.

 

Gooder price, but morer maintenance. Once in a while I blow dust off the tops of my AGMs.

[Pat & Pete]

Gooder price, but morer maintenance. Once in a while I blow dust off the tops of my AGMs.

 

Thanks for reminding me . I haven't even done that in a couple years .

[D&J]

Gooder price, but morer maintenance. Once in a while I blow dust off the tops of my AGMs.

Most of the time I forget they are even there.

 

Denny

[Yarome]

I'll admit, AGM's have some very definite advantages. Yearly maintenance being.. open the battery compartment and confirm they are still there being one. Higher charge rates, practically non existent self discharge during storage (~1%/30), more flexibility in placement (jammed and stacked sideways in the closet or enclosed bay) being just a few more.

 

The additional cost can easily be justified. For the casual camper.. probably not as much, but they certainly have their place.

[Pat & Pete]

I'll admit, AGM's have some very definite advantages. Yearly maintenance being.. open the battery compartment and confirm they are still there being one. Higher charge rates, practically non existent self discharge during storage (~1%/30), more flexibility in placement (jammed and stacked sideways in the closet or enclosed bay) being just a few more.

 

The additional cost can easily be justified. For the casual camper.. probably not as much, but they certainly have their place.

 

I would think exactly the opposite . ???

[Yarome]

I would think exactly the opposite . ???

 

In a sense yes. Some of the advantages would definitely benefit the casual camper.. ease of maintenance. I was referring more to the price tag. Most casual campers have a difficult time justifying $600 for a couple AGM's when they can pick up a couple box store GC's for under $200 and don't mind forking over for a new set every few seasons.

 

But you're right. AGM's would be more forgiving to neglect.

[Dennis M]

I've been very happy with Optima's, to me the best feature of AGMs is the very low rate of internal discharge.

 

I had a pair of Optima's in a vintage race car for many years. Prior to selling it sat untouched for two years and then started on the first crank.

 

I currently have Batteries Plus AGMs in the fiver. Never pay the least attention to them. Up until this year, when we have been living in the fiver for 12 months, the fiver would sit for five or six months at a time.

[xctraveler]

One other disadvantage of Flooded Cell batteries in my experience is the corrosion of the entire battery compartment from the out gassing. In my case I had a spray can of terminal coating stored next to the batteries and came back to find the can had rotted and spilled its contents into the tray - hey it protected the tray but that was not the goal. I expect to have a much cleaner battery compartment with the 4 AGMs I am installing.

[297550]

One other disadvantage of Flooded Cell batteries in my experience is the corrosion of the entire battery compartment from the out gassing. In my case I had a spray can of terminal coating stored next to the batteries and came back to find the can had rotted and spilled its contents into the tray - hey it protected the tray but that was not the goal. I expect to have a much cleaner battery compartment with the 4 AGMs I am installing.

Off gassing of lead acid batteries is both hazardous and corrosive and requires the battery compartment be vented. They also require periodic maintenance (adding distilled water, balancing, battery terminal cleaning, etc.). For these reasons, the expensive AGM batteries are well worth the cost IMHO. I have Lifeline AGM's. But each person must decide for themselves if the cost is or is not worth the price premium.

[Optimistic Paranoid]

Optima batteries used to have an excellent reputation for quality. Unfortunately, the original owners sold the company to Johnson Controls in 2000. JC promptly moved production from the US to Mexico. Following which, quality control went to Hell in a handcart. There are lots of better AGM batteries out there now.