Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

cdherman

OK, Have read and searched and cannot quite answer the question. Really apprecaite any and all responses.

I have one dedicated circuit in my home that feeds certain critical things: cordless phone base station, wireless router and cable modem, vonage box, and alarm/smoke system. These things I do not want going down during a tornado or t-storm when I am hunkered in the basement.

For years I ran that circuit with an old APC 1400, but it cooks batteries in about 2.5 years. Found out that it floats the 24v pair of bats (SLA) at 27.6v, which over time eventually causes them to enter thermal runaway and that's the end... After a great deal of trying to "fix" the excessive float, I have decided to but a new inverter/charger.

Probably a Xantrex Prosine 2.0. I know -- overkill for my few items listed above. But I'd like to be prepared for other "contingencies" as well.

The battery will be in the basement in a rather enclosed space, and I am a lazy man, so checking electrolyte will be difficult to assure. Thus my desire for AGM.

I am looking to get one 12, or 2 sixes, and I don't want the bat(s) to weigh more than say 60-65 lbs since the space will require manually positioning the bat and I not as young as I used to be....

I will kill grid power every month or two and allow the inverter to power the loads till the bats are down to about 80% SOC just to verify that they are alive and well.

So these bats will get used rarely, and mostly just float.

I'd like some rec either specifically or generally as to Ah/$ -- I assume that larger bats usually give more Ah per $ right? But since I have an upper level in terms of weight, are there any other considerations? Obviously, I want a good brand as I want these to last as many years as possible.

Thanks in advance....

Blackcherry04

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

Easy answer, Sams Club, Costco GC-2 AGM golf Cart Batteries, $159.00 ea + $15 core charge, they take any car type battery on core charge. Make sure they within a few months of manufacture and not two years old on the shelf. They are about 60 Lb and 180-190 Amp Hr @ 12 Volts.

RCinFLA

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

I have a similar system. Primarily a UPS system but large enough to handle long outages during storms.

In this application you should also consider costs of float support kWH's consumed over battery lifetime in overall cost calculations. Golf cart batteries are lead-antimony based which have higher leakage support then lead-calcium based batteries.

Blackcherry04

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

RCinFLA wrote: »

In this application you should also consider costs of float support kWH's consumed over battery lifetime in overall cost calculations. Golf cart batteries are lead-antimony based which have higher leakage support then lead-calcium based batteries.

Is there a distinction between Flooded and AGM Grids ?? I know Trojan touts there T-105 's as high antimony grids, but I see few others talking about it, but that is flooded batteries.

""Lead-calcium positive plates may grow in length and width because of grid oxidation at the grain boundaries. This oxidation is usually caused by long-term overcharging, which is common to UPS and other batteries on constant-float changing. Grids may grow in size sufficiently to cause buckling or rupture of their containers.""

westbranch

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

there are a few recent threads re: Li type batteries. they may be better for long term storage light use.

cdherman

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

Blackcherry04 wrote: »

Easy answer, Sams Club, Costco GC-2 AGM golf Cart Batteries, $159.00 ea + $15 core charge, they take any car type battery on core charge. Make sure they within a few months of manufacture and not two years old on the shelf. They are about 60 Lb and 180-190 Amp Hr @ 12 Volts.

That sounded like a good idea so I went to my local Costco today (the web site shows no such battery). Well, they did not stock it either, but I found the battery catalog in the automotive section, found the Costco item #245725 and asked the attendant to check availability at other stores. There were some out there,, but alas, too far away for my remaining charge in my Leaf.

So I went back home and googled that item # -- seems like hits mostly are vague or state that the GC2 bats from costco are flooded. So now I have to decide if its worth the hassle of driving an extra 30 miles to check the costco's out in person. Anyone perhaps know more. The GC bats from Sams are flooded, per their description of having caps I would deduce, though they did not really describe technology.

It is a temptation to toss a couple good quality flooded 6v in a battery box in the basement corner and find a way to remember to check fluid levels with regularity. I am not as much worried about explosion risks, as I am of the fact that I also have another corner (30 feet away) where I do gunsmithing work and reloading with a lot of delicate stuff that have to never have any increased corrossion risks. Even at a distance, ANY extra hydrogen sulfide makes me nervous.

Blackcherry04

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

cdherman wrote: »

That sounded like a good idea so I went to my local Costco today (the web site shows no such battery). Well, they did not stock it either, but I found the battery catalog in the automotive section, found the Costco item #245725 and asked the attendant to check availability at other stores. There were some out there,, but alas, too far away for my remaining charge in my Leaf.

So I went back home and googled that item # -- seems like hits mostly are vague or state that the GC2 bats from costco are flooded. So now I have to decide if its worth the hassle of driving an extra 30 miles to check the costco's out in person. Anyone perhaps know more. The GC bats from Sams are flooded, per their description of having caps I would deduce, though they did not really describe technology.

It is a temptation to toss a couple good quality flooded 6v in a battery box in the basement corner and find a way to remember to check fluid levels with regularity. I am not as much worried about explosion risks, as I am of the fact that I also have another corner (30 feet away) where I do gunsmithing work and reloading with a lot of delicate stuff that have to never have any increased corrossion risks. Even at a distance, ANY extra hydrogen sulfide makes me nervous.

Well here is Sams AGM battery.

http://www.samsclub.com/sams/duracell-agm-golf-car-battery-group-size-gc2agm/prod3870119.ip?navAction=push

I see the problem, they are not available in MO or KS.....dang
ONLY AVAILABLE IN AL, CT, DE, FL, GA, IL, IN, KY, MA, MD, ME, MI, MS, NC, NH, NJ, NY, OH, PA, RI, SC, TN, VA, AND WV

You box them in a plastic tub of some kind and hook a vent tube on it. It's probably not the best to have them in your house, although I have 2 in mine for the last 30 years. I set a fan in the window when I EQ them. My boat has 20 batteries, they are vented the best I can, but if I am EQing it'll go out and blow back into the window sometimes. Cabella's has some AGM that I was tempted to try. Shipping is the killer on any of them.

rgk1

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

I have pondered the Sam's Club AGM golf cart batteries that Blackcherry04 mentioned as an option for me in the futue. For $159 at my local Sam's sounds pretty good. They appear to have caps on them, but I am sure just pressure relief under them. They are rated at 190ah at the 20hr rate and are 6 volt, but are "ONLY AVAILABLE IN AL, CT, DE, FL, GA, IL, IN, KY, MA, MD, ME, MI, MS, NC, NH, NJ, NY, OH, PA, RI, SC, TN, VA, AND WV" according to the website. Has anyone here used them or know anything else about them?

Blackcherry04

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

rgk1 wrote: »

I have pondered the Sam's Club AGM golf cart batteries that Blackcherry04 mentioned as an option for me in the futue. For $159 at my local Sam's sounds pretty good. They appear to have caps on them, but I am sure just pressure relief under them. They are rated at 190ah at the 20hr rate and are 6 volt, but are "ONLY AVAILABLE IN AL, CT, DE, FL, GA, IL, IN, KY, MA, MD, ME, MI, MS, NC, NH, NJ, NY, OH, PA, RI, SC, TN, VA, AND WV" according to the website. Has anyone here used them or know anything else about them?

I looked at them the other day, it just looks like a cap, it doesn't come off. Other than that , I don't know anything about them.

westbranch

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

Just because they are AGM does not mean they don't vent, it DOES happen (VENT) if they are overcharged... ie if gasses are generated at a rate that exceeds the recombination rate.

BB.

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

AGMs can also vent at "end of life" (when catalyst has failed).

-Bill

techntrek

Re: Best Ah/$ ratio AGM Bat for Backup UPS, request for advice...

cdherman wrote: »

...

It is a temptation to toss a couple good quality flooded 6v in a battery box in the basement corner and find a way to remember to check fluid levels with regularity. I am not as much worried about explosion risks, as I am of the fact that I also have another corner (30 feet away) where I do gunsmithing work and reloading with a lot of delicate stuff that have to never have any increased corrossion risks. Even at a distance, ANY extra hydrogen sulfide makes me nervous.

I've had 16 12 volt batts (96 cells) to check for the last 5 years and its no fun when its time to check and fill them. I now need a much smaller battery than I did 5 years ago so the upcoming battery replacement will be back to sealed UPS batts - so I don't have to deal with that anymore.