Community Forums

our3sons · 05-13-2018, 09:09 PM

I am evidently behind the battery curve. A friend just got an Absorbed Glass Mat (AGM) battery and was telling me about the extended life. I'd never heard of it. I've looked around and seen what I would be looking for (24M) from about $90 to $300+. Does anyone out there have any experience with the AGM battery in their RV? And was it good or not? Thanks!

Tony Lee · 05-14-2018, 03:42 AM

They do have some advantages - mainly because they are fully sealed and don't require regular maintenance and can take a slightly deeper discharge than regular batteries - but they are more expensive and heavier and probably less tolerant of poor charging practices than flooded cell batteries.

Do you have any particular problems with your existing setup? Because merely changing to AGMs may not give a desired outcome

twinboat · 05-14-2018, 04:46 AM

AGM batteries, for the regular user, are just 3 times more expensive batteries that you don't have to clean with a hose and check the water in every 1 to 3 months.

If you compare performance, they match good old flooded batteries, except you can charge them at a higher rate. To charge them at a higher rate, you will need to upgrade your charging equipment.

yowmemperor · 05-14-2018, 11:29 AM

Someone provided there links a while ago. I am more familiar with lithium than LA and AGM, it is helpful.

The 12volt Side of Life (Part 1)

The 12volt Side of Life Part 2

Phil Perrin · 05-14-2018, 05:03 PM

I've been in the battery business for over 20 years. The one thing I've noticed about AGM batteries is that when they go, they go. Not much of a warning, unlike flooded batteries.
Wet, or flooded, batteries get weaker and weaker, until they won't hold a charge as long. Eventually, they just stop taking a charge altogether.

our3sons · 05-16-2018, 08:21 PM

Quote:

Originally Posted by Tony Lee

They do have some advantages - mainly because they are fully sealed and don't require regular maintenance and can take a slightly deeper discharge than regular batteries - but they are more expensive and heavier and probably less tolerant of poor charging practices than flooded cell batteries.

Do you have any particular problems with your existing setup? Because merely changing to AGMs may not give a desired outcome

Nothing wrong with the current system...that I can tell. My friend had just mentioned he bought one for the trolling motor and depth finder for is boat and what he was telling me sounded good. So just curious to know if the AGM is all that!

We have a couple Interstate SRM-24 batteries (not in parallel...no room in the cubby) that went low fairly quickly. that's either us spending too much time in the TT (not hiking or such stuff) or there's a drain on the battery I don't see. It was our first time out in this trailer but it still seemed a little quick from what I remember.

our3sons · 05-16-2018, 08:28 PM

Quote:

Originally Posted by yowmemperor

Someone provided there links a while ago. I am more familiar with lithium than LA and AGM, it is helpful.

The 12volt Side of Life (Part 1)

The 12volt Side of Life Part 2

Thanks for the links, I'll be keeping those. Good stuff to know.

our3sons · 05-16-2018, 08:32 PM

Thanks all for the info. I think I'll just stay with my Interstates for now. I think I will re-route the cable to a larger area up front so I can get them in parallel. I'll follow the wiring as much as I can just to make sure I don't have a drain somewhere. I already pulled the fuse on the stereo.

wa8yxm · 05-17-2018, 07:34 AM

Are AGM batteries Good. YES. are they worth the extra cost. I think not.

I have heard the clais of "extended life" I have not been able to confirm either by RESEARCH (Battery maker web pages) or by personal testing.

I tried AGM.s put 'em on a 2nd loop in the RV (Inverter) programmed for AGM. They were the newest batteries in the RV (Some of which are older than the RV) and they were the first to fail. So I do not believe the "Longer life" claims.

They are however, maintenance free
And you can mount them without respect to 'This side up"
and you can put them in places you can not put a flooded wet.

But other than that... I'm not sold on 'em.

ysidive · 05-24-2018, 04:37 AM

The main issue with batteries is that many do not check the water levels in the battery.. If the levels are not maintained it will cause the battery to fail prematurely... Most say that they need to check the batteries and then forget or put off till tomorrow.... With AGM batteries this is not a problem... Also they can be discharged much further than a normal lead acid wet cell battery and still be recharged... If you a re a Sams club member check their AGM's I bought two for my boat for about 170 bucks apiece...Don't worry about the brand, as their are only about 3 manubacturers of batteries in the US and the put a variety of labels on them... Penn Manufacturing makes many batteries with the same specs with different brand labels.... Check out their spec sheet online and compare with the specs of the brand you are purchasing.... The same battery manufactured by Penn sold at Battery Plus, or West Marine was about 2to2 1/2 times more money than the ones I purchased at Sams Club....

twinboat · 05-24-2018, 06:22 AM

Quote:

Originally Posted by ysidive

The main issue with batteries is that many do not check the water levels in the battery.. If the levels are not maintained it will cause the battery to fail prematurely... Most say that they need to check the batteries and then forget or put off till tomorrow.... With AGM batteries this is not a problem... Also they can be discharged much further than a normal lead acid wet cell battery and still be recharged... If you a re a Sams club member check their AGM's I bought two for my boat for about 170 bucks apiece...Don't worry about the brand, as their are only about 3 manubacturers of batteries in the US and the put a variety of labels on them... Penn Manufacturing makes many batteries with the same specs with different brand labels.... Check out their spec sheet online and compare with the specs of the brand you are purchasing.... The same battery manufactured by Penn sold at Battery Plus, or West Marine was about 2to2 1/2 times more money than the ones I purchased at Sams Club....

The above statement about AGMs tolerating a deeper discharge then flooded batteries is not true.

If you research lead acid batteries, flooded or AGM, you will find nearly the same DOD ( Depth of Discharge ) specs.

Both types, AGM and flooded, list about a 1000 cycle at 50% DOD and about 500 cycles at 80% DOD.

AGM batteries are maintance free and can be charged at a higher amperage rate, if you have the proper high output charger, but that's about it.

wa8yxm · 05-24-2018, 07:15 AM

Just so you know.. Two pair of GC-2 Flooded wet cell batteries can easily take 120 amps of charge current.. I do not know of any converter that puts out that much. Mine is 80 and my back up is 100 but if I add 'em together I only get about 60 flowing into the batteries due to the way they work.

And LIFELINE brand is the only one that advertises faster chargeing.