AGM 12V Battery Recomendations

[Vedette]

Okay, after years of being a non-Dry Cell Battery guy.
I am considering a AGM for Kermit, due to venting concerns.
But, my research on the internet has been frustrating to say the least.
I just want to know what my options are and what the best choice might be?
Please don't be shy about giving advice here! But, please speak English.
Brian

[MtnDon]

Give us a clue as to how many amp-hours capacity you figure you need? Is it more like 50, 100 or 200+ (calculated at a nominal 12 volts)


In any event, I believe the Trojan Reliant AGM is the only true deep cycle AGM around. 6, 8 and 12 volt versions. There could be others I don't know about. Lots of RV/Marine wannabe's that use the words deep cycle in vain.

[noseoil]

Brian, I bit the bullet & got a group 27 Trojan AGM 12 volt. Had to scrap the idea of using a tow-while-charge system, since I have heat to worry about where I live in the summer. They're a bit different than a wet battery. They shouldn't be charged if the battery is above 120 degrees or below 32 degrees (F for both). That's why they don't do well under the hood in summer. Max charge voltage should be kept at no more than 14.4 as a higher voltage for too long can cook the AGM. Basically, they act like a flooded battery, but can cycle much deeper & will charge back up faster after each cycle. A flooded battery can't keep up with the duty cycles.

One good source, if you don't need a full size car battery, is wheel chair batteries. They are smaller in size & weight but still have a fair amount of storage capacity. They range from 35AH & up (55AH, 75AH, etc ).

I use solar for my charging & so far so good, a 100 watt panel is fastened on the roof. Other people use remote plug-in panels (the folding type) & a wire to the electrical system for charging. There are lots of ways of charging available now. One thing you will need is a good charging module if you go with a solar panel. I have one of these on the way that I will use instead of the cheap Renogy one I got with the solar panel & system. Morningstar SunSaver SS-10-12v Charge Controller 10A 12V, about $45 from amazon. My concern with the Renogy one is that it's really set up for a flooded battery, & I don't want to take a chance on the battery. It is a better charger & should last a long time.

What Don said is true! Add up all of your needs for the system & then figure out what size battery will work for you, then figure out where to put it, how to charge it & what you need to keep it happy. Best of luck, there's a lot of confusion out there with this stuff, but a basic system is pretty simple to make & maintain.

[Shadow Catcher]

When I was searching I looked at Concord who makes military and aircraft standard AGM batteries. They make Lifeline batteries for RV and marine use. Our camping often is in shady camp sites and we rely on a 185W high voltage panel and Morningstar SunSaver MPPT contoller. I monitor using a Vectron battery monito. The whole system has exceeded my expectations I can't say more. http://www.lifelinebatteries.com/
"Lifeline Batteries have earned global recognition as the premium sealed AGM battery technology. Professionals from a multitude of industries have benefited first hand from the overwhelming success rate of our battery line. Lifeline Batteries are manufactured in West Covina, California by the Concorde Battery Corporation and is a US family owned and operated company. The Lifeline Battery technology is a direct spin off from Concorde's industry leading aerospace battery lines. All of these batteries satisfy the rigorous demands from many branches of the US Military and a host of industrial and private sector applications. (i.e. UL, ISO, Mil-Spec, USCG, DOT & MSDS.)"

[Cosmo]

A simple rule for batteries and money Is - If your outgo exceeds your income your upkeep will be your downfall!

I started with figuring out how much power I use. I measured the draw of all the LED lighting, stuff I charge, radios, computers, AA and AAA batteries, how long I run how many lights) etc. Once I knew that I could figure out the amp hours I needed and what solar panel I needed to charge it.

The most often charge rate (most desirable rate to charge the battery) I kept bumping into C10 (charge at 1/10 the amp hour capacity of the battery for best battery life) Many batteries can be charged at higher rates but it might shorten the life of the battery.

The opposite is true too If you put a heavy load on the battery (20 amps load on a 55 amp batter)– if may shorten the life.

I calculated my max usage a day would be 7 amps total a day. My peak load would never be more than 3 amps.
So ended up with a 55 amp hour AGM deep cycle battery. The AC charger is 6 amps (http://www.amazon.com/BC6BDW-Waterproof ... mp+charger)– close to my 1/10 charge rate. The solar panel is a 5 amp hour again close to my C10 1/10 charge rate. Adjust the numbers to your battery makers recommendations.

I have been teardrop’ing for a year. The electrical is working out great so far. I am usually off grid and have no problems with solar even on cloudy days under trees (but I keep an eye on how I am doing and adjust as needed. I charge up all the rechargeable stuff during the day (phones AA batteries computer etc.) when I have excess solar power and use the AGM for typical use at night.

I now know I could get by with just the solar panel - I charge with either a connection to the car (when driving) or a 100 watt (5 amp hour) solar panel using a Flex Charge PV7 solar controller(http://flexcharge.com/PV7D.html) . Or AC with a 6 AMP Black and Decker waterproof charger. I add in 10% for loss of efficiency when charging. That means If the charge rate is 6 amps I may not actually get a full 6 amps due to some loss. I may get 5.4 amps.

There are plenty of meters available to help with all this but I did fine with a simple amp meter ($10) to measure the current of the lights or radios I am running. I kept a list to get the total.

I am using a Full Force AGM 55 amp hour battery to power my teardrop.
Specification PDF for the AGM shows discharge rate under different loads I though this might be useful for comparison with other batteries. See if you can get the spec sheets for any battery you buy it show more than the few numbers most web sites provide. The manufacturer are usually happy to provide the info.

http://resources.fullriverbattery.com/f ... D55-12.pdf
According to the Characteristics box on the chart I would only get 66% of the 55 amps at -15F temps.

According to the chart (Constant Current Discharge) at 77 degree I could draw 3 amps for about 20 hours. I suspect that would take the battery below 11 volts which is my personal cut off point to avoid damaging the battery.
At 6 amps I will get just under 8 hours. Knowing that kind of battery behavior helped me hit my target when buying and alerted me what to expect when camping. Cold Is a wildcard but there is similar info available from the manufacturer to help there too.

The combination I am using is perfect for my needs. Solar panel is really great.
I Most battery companies show the output for 70 or 80 degrees F. The capacity drop as the temp drops. I find the battery discharges quicker and takes longer to charge at low temps. Its worth calculating that if you camp below freezing.

Sorry I blathered on o long. I tried to avoid technobabble. I had lots of help along the way. But I ended up with what I needed and have an idea of the limits of my setup I summer and winter.

Cosmo
PS My trailer was delivered with all LED lighting except for the porch lights which were incandescent bulbs (2) which drew 1.25 amps each. I swapped it with an LED which is about 20% brighter and only draws 1/5 of the current or .25 amps. These kind of swap's can save lots of electricity.

[vincigj]

I kept it simple. Using 32ahr batteries plus agm, deep cycle. Solar panel 20watt through a cheap charge controller. Volt meter, clock, outside temp display to watch the trend. All lights led except reading lights. Wife like softer color. Fan biggest draw @ 1.3 amps. 1 week use going to an back for CRA and never got to charge it and never drew it down. Always thought that if it wasn't enough I could redo it. Comes from the "they never are done mentally ". Ymmv.

[Vedette]

Thanks guys.
All I have gathered from what has been said so far (that I can understand) is a couple of "Brand Names".....sorry I am so dense!
But, talking about formulas, with abbreviations and comparisons that someone doesn't recognize ......is like explaining it in a foreign language.
Up until 3 years I had never heard the term Amp hours? and still have no real handle on what that means.....so how would I know what I am going to need.
Maybe I should have listed my needs?
Biggest power draw for us is our 4.4 amp draw fridge. Currently draw our wet cell deep cycle battery down in about 15 hours (we run two small computer fans all night while we sleep).
While we are driving we charge with the car.
Most of the time we are camped at Campgrounds that allow us to plug into a 30Amp service to allow our converter to make everything happy during our stay.
When we are off of the grid we have a 90W Samlex Solor panel (which we have yet to use) that plugs in as if the TD was plugged to the car during travel time.

I just want to switch to a Sealed, Dry Cell, Battery that won't emit fumes????

Does this help?
Brian

Size , cost, and weight do not matter!
But it would be nice if all three were lower rather than higher!

[S. Heisley]

This is what I am using: http://www.jazzy-electric-wheelchairs.c ... 2-Volt.htm

Please recognize that you will want to adjust your battery size to your needs. I don't need that much anymore; but, mine was selected 'BL' (Before LEDs).

I had heard that a wheelchair battery was my best bet; and, after deciding on the MK, I called a wheelchair supply store and asked them about it, just to be certain. Even though they didn't sell the one that I wanted, they gave glowing reviews for MK. They told me that it has the longest shelf life of any battery. (That means not connected to anything; or, battery disconnect switch turned to 'off'.) In fact, they said that it was the only wheelchair battery that they would carry because it is that good. They told me that they even had one lady who used a wheelchair whose MK battery lasted 10 years. That sold me on it. So far, I am on year 5 with mine (knock on wood) and I even accidentally ran it all the way down to totally out of power once.

PS. AGMs do emit a small amount of gas when you first start the charge-up, but not much.

I have a chart somewhere that I used to calculate my amps/battery needs. I'll find it and post it for you.

[Vedette]

Thanks Sharon
what sight are you in at Shasta?
Brian

[S. Heisley]

Here ya go:




Again, please remember that this was BL (Before LEDs), so, don't be shocked at the AMPs used.

If this makes sense to you, I can send it to you. (I think I still have your email address.)
It's and Excel spreadsheet and you know how to work with those; so, all you'd have to do is change the amps for your light fixtures, etc; or, send me your info and I can work it up for you.

I forget...I think, #34

[vincigj]

Hey Vedette. My battery,32ahr, is to small for your needs. Good luck

[Vedette]

Same or close to last year?
Brian

[S. Heisley]

...Close to 2014 site, a little farther away from where I was last year.

I sent you the Excel spreadsheet. Watch for TinyTrailer email.

[GuitarPhotog]

I have an Interstate AGM "Deep Cycle" 60AH battery that has suited my needs for 5 years now. I charge from the car, from a 90W solar panel, or from shore power.

Yesterday I went out to show someone the trailer and discovered that the battery is dead, as a doornail Apparently when I was rewiring light fixtures in the shop to convert from fluorescent to LED, I neglected to turn the breaker for the outlet feeding the trailer back on.

I'll let the battery charge for a day or two and test it to see if I've killed it.

I may be purchasing a new AGM battery soon. It has to be AGM because it's in the cabin.

<Chas>

[Vedette]

Hi Carlie
I knew I should have just asked you first!
Brian