Inexpensive AGM Battery

pechan

Does anyone have any thoughts or experiance with apex battery?
I looks like it is a private labeled UB, Universal Battery, to me. 200 amp hours at 12 volts for $250.00

http://www.apexbattery.com/12v-200ah...GguhoCxHPw_wcB

Would these work well for a small stand alone dedicated solar system?

Matt

Photowhit

I just glanced at the specs, and while I like that it says it has "extra thick plates"...

I am suspicious about the "Pb-Ca-Cn Alloy" Pb = lead Ca=calcium Lead calcium tends to be starting batteries at least in the flooded battery world.

Also the CCA 1450 leads me to believe this is primarly designed to deliver a lot of energy quickly rather than a little energy over a long period of time.

But they call it a solar battery....

Did you catch the Warranty line?

"... AGM Solar Battery has a warranty of 12 months. Our products generally last about 3 times the warranty period..."

westbranch

What do you plan to power from them?

The specs show a CCA rating, so that puts them in the category of STARTER battery, not deep cycle, made for short, large discharging...

Photowhit

Are you uncomfortable with the flooded golf cart battery maintenance? $200 would get you @208ah 12 volt battery bank at Costco or Sam's club.

pechan

Thanks for the suggestions. I did see the CCA rating, but they are advertising it as a "Deep Cycle" that is why I was trying to see if anyone here had tried one.

The application is a 60 watt motor driving a chemical injection pump. The pump runs 6, 2 second cycles per minute, 24/7. I have measured the actual draw over a 48 hour period and it came to about 34 amp hours @ 12 vdc.

I will be using a 140-150 watt solar panel and a pwm charger controller to power the unit.

I do not want to use a flooded battery due to the fact that I will not be the person maintaining the units and cannot trust the end user to check water levels etc.

Do you guys have any experience with Universal Battery AGMs? WholesaleSolar seems to praise them on their website... Was also looking at their 4D AGM 200 amp hour Battery.

Matt

BB.

A little math (to make sure I understand your setup):

• 34 amp*hours * 1/48 hour period * 24 hours per day = 17 AH @ 12 volts
• 17 AH per day * 2 days * 1/0.50 maximum discharge = 68 Amp*Hour @ 12 volt battery bank minimum recommended.

Guessing your solar panel is:

• 140 Watt * 17.5 volts Vmp = 8.0 Amps Imp

If you assume an average pretty bad gloomy winter day of 1.8 hours of sun per day:

• 17 AH per day * 1/8.0 Amp panel = 2.1 Hours of sun per day minimum to "break even"

I would suggest that you double the panels to two 140 Watt panels in parallel on a PWM controller--Just to give you a larger margin of safety--Unless this is installed in some relatively sunny region.

Battery bank should be charged at 5% to 13% rate of charge. Say you have a 200 AH @ 12 volt battery:

• 200 AH * 14.4 volts charging * 1/0.77 panel+controller derating * 0.05 rate of charge = 187 Watt array minimum (good for seasonal/weekend use)
• 200 AH * 14.4 volts charging * 1/0.77 panel+controller derating * 0.10 rate of charge = 374 Watt array nominal (daily off grid usage)
• 200 AH * 14.4 volts charging * 1/0.77 panel+controller derating * 0.13 rate of charge = 486 Watt array "cost effective" maximum

So--A 200 AH battery seems to be a bit of over kill--But it really depends on how local conditions (latitude, local weather conditions, etc.). Notice the size of the solar array not only depends on daily loads and hours of sun per day, it also depends on the Amp*Hour rating of the battery bank. Larger battery banks should have larger solar array to properly/fully recharge.

AGM batteries are much more efficient than flooded cell batteries--So, you can get away with a smaller battery bank than the "nominal" solar array I have suggested above... But, I would still suggest that you run at least 2x 140 Watt panels in parallel. This will help keep the AGM battery bank happy (solar panels have never been cheaper, and AGM batteries have never been more expensive).

AGM batteries (even very good ones) still tend not to last as long as as decent flooded cell batteries with good maintenance.

But, for remote/unattended/automated systems, you run a risk of the batteries being over discharged in bad weather (or load failure--say pump "stays on instead of cycling"... Lead Acid batteries are not usually easy to estimate state of charge based on battery bank voltage--But for this system, you do have a choice... Let the system run until the batteries die, or get a PWM controller (or voltage based switch) that turns off at ~11.5 to 12.0 volts, and turns back on at ~13.6 volts (when battery has been recharged some).

One thing that lead acid (and AGM) batteries do not like is being discharged below 20% state of charge (and in general, try to avoid discharging below 50% state of charge). So, having a large solar array and some sort of low voltage/low state of charge cutoff will help extend the life of the batteries themselves.

-Bill

Photowhit

I just read that most lead acid AGM batteries are Lead Calcium, so I'm going to stand in the corner for a while. They might work for deep cycle AGM...

...Sorry

inetdog

Photowhit wrote: »

I just read that most lead acid AGM batteries are Lead Calcium, so I'm going to stand in the corner for a while. They might work for deep cycle AGM...

...Sorry

FWIW, even a deep cycle AGM will have a low enough internal resistance that it would be reasonable to put a CCA rating on just for the odd special use.

Vic

Believe that Sealed batteries -- AGM and Gel -- are Lead Calcium, as Gassing is not desirable.

And, Not to be too picky, but, have said this here, many times in the past -- Battery manufacturer specs that state CCA, MCA and Reserve Capacity are not necessarily an indicator of a Starting or Dual Purpose battery. Surrette battery specs CCA, MCA and RC on almost all of their Renewable Energy Deep-Cycle batteries. For example:

http://rollsbattery.com/public/specsheets/2YS62P.pdf

http://rollsbattery.com/public/specsheets/4KS25P.pdf

The 2 volt battery above, has a CCA rating of 11,480 Amps. This is probably not necessary for almost ANY engine-cranking job from this approximate 4,400 AH Capacity battery, IMO.

These are simply reference specs from a manufacturer that is trying to give as much information as possible.
FWIW, Vic

Darryl

I just ran 140 W panel 34 AH/day load in st cloud MN on real data set, (using my simulation routine) I see LOL (loss of Load) occuring on three occasions in Dec and one in January I then reran on 280 watt panel and saw no LOL. So my simulation says BB is correct. For a more accurate simulation use HOMER and load your hourly data from NREL PVwatts.

softdown

Warranties are only as good as the company standing behind them. Rolls has a long warranty and a reputation for blaming problems on the end user instead. Deep cycle batteries often have one year warrantee's. I don't blame them as solar batteries can be destroyed in a few days. Or a few hours of overcharging and boiling. Especially AGM and Gel batteries.

softdown

This is a similar CCA and weight to the 8D battery used in large trucks. Thick plates lower CCA while offering greater discharge/recharge capabilities. Perhaps 8Ds have moderately thick plates. 1400 CCA is not a significantly high number for a 125 pound battery.

Also....have you recovered shipping costs for these batteries?

Vic

softdown wrote: »

This is a similar CCA and weight to the 8D battery used in large trucks. Thick plates lower CCA while offering greater discharge/recharge capabilities. Perhaps 8Ds have moderately thick plates. 1400 CCA is not a significantly high number for a 125 pound battery.

Also....have you recovered shipping costs for these batteries?

Believe the above comment was directed at my last post.

OK the first Link to the Surrette site was for the 2YS62P. This is a 570 pound 2 volt battery ... if one was going to make a 12 V battery (like the 8Ds), it would weigh about 3420 pounds. This would make it a nominal 4400 AH 12 V battery.

And, also from that link, one will be able to read, that the CCA is actually Eleven Thousand Four Hundred Eighty Amps -- 11,480 A. This seems a bit more stout than the 8Ds that I've encountered.

Regarding battery shipping from NS, shipments in excess of 4,000 Lbs shipped "free". (at least to the West Coast, in 2005). And, each 1280 AH 48 V battery bank tipped the scales at just over 4,000 pounds ... So the shipping cost was recovered immediately. But, of course, the customer always pays shipping, weather "free", or not.

Regarding Surrette battery performance, these banks have been top-notch. Been in service for ten years, and appear to be doing fine. One cell of one battery was damaged in shipment, and Surrette immediately shipped a Dry replacement cell -- I cannot fault Surrrette battery performance at all whatsoever, and their Warranty performance has been stellar, in my personal, direct experience. On these Forums, we tend to hear from those who have a problem/issue with systems. Those who are delighted, we tend to hear much less about.

Not to try to put a too-fine point on things,. FWIW, Opinions and experiences. Good Luck, Vic

Alaska Man

My 220 ah AGMs are from FullRiver Battery, I paid about the same price for this http://www.fullriver.com/products/admin/upfile/DC224-6A.pdf proven battery here in Alaska. They have performed without issue now for about 3 years. I have seen no decrease in performance to date.

softdown

I must be missing something? Those are 67 lb six volt batteries vs 117 lb twelve volt batteries.

Has anybody dug up their shipping fees?

Alaska Man wrote: »

My 220 ah AGMs are from FullRiver Battery, I paid about the same price for this http://www.fullriver.com/products/admin/upfile/DC224-6A.pdf proven battery here in Alaska. They have performed without issue now for about 3 years. I have seen no decrease in performance to date.