Is this battery price too good to be true?

Dave Angelini

The only time I advocate is at happy hour.

softdown

Wondering about the cabling costs to join twenty four 2 volt batteries. What sized cables do you old pros advocate?

Dave Angelini

I only use 4/0 and for everything as the breakers on the pre-wired panels are always 250A.
The cables are about $10 pre-made UL sourced from my supplier.

Marc Kurth

Most of my customers use strictly 4/0, but a few prefer bus bars for the interconnects.
Some L16's have two pairs of terminals for very high output applications, and 4/0 is still used.

Marc Kurth

Dave Angelini said:

The only time I advocate is at happy hour.

Now that's a good plan!

softdown

All ye of little faith....Eat your heart out. My 10 arrived this afternoon. One meter shows 12.59 volts with 9.7 volts in the meters 9.6 volt battery. Another meter of more dubious quality reads 12.4 volts.

Moving them from their truck to my truck was a chore. 173 lbs is about all that I can repeatedly carry around. Had to do it again when I got back to the shop. I'll be a bit sore tomorrow...but satisfied. They appear to be excellent batteries. Though the carrying ropes is for smaller hands.

Photowhit

Haha...

You bought 10? how does that break down?

FWIW - batteries voltage has zero to do with it's capacity. Unless it can't be brought back to full voltage...

softdown

You want to check the SG on AGM batteries?  Battery voltage on "new, untouched" batteries says plenty.

My bank of batteries is still doing fine. I may try to move these batteries.

If unable to sell them (distinct possibility), I'd like to have a couple replacements for a string of eight.

softdown

Marc Kurth said:

Photowhit said:

Marc, I understand that Full River and 1 other manufacturer (Optima? though maybe not, I think Optima was sold off by Full River) use a pure lead (not a composite) by tightly sheeting their agm plates and separator sheets. I guess 2 questions, is this true, and have you seen real world advantages?

As I have said before, I can only offer my opinions based on what I have observed, measured/verified/checked. Yes, I have become extremely opinionated in the process. While my business is purely batteries, battery banks for PV systems is only part of my core business.

Yes, each AGM manufacturer uses a proprietary design and production method for their cell construction. While everyone talks about tight packing, Fullriver and Concorde will not discuss it.

Several companies now push the fact that they use 100% pure lead and it is indeed true for Concorde and Fullriver. But it seems be becoming a buzz word for more companies. When the marketing boys and girls go into high gear, I become wary and slow down.

Do I see a real difference in the field, that I can directly attribute to 100% pure lead? Ummmm - not compared to the quality control and inherent design parameters of the plates, mats and bus bars.I am NOT saying that it doesn't matter!  I am only saying that I can't measure what pure lead is doing for me. But yes, I do believe that design and implementation is the difference.

Go basic for a moment and compare the major AGM manufacturers charge/discharge specs and most will look surprisingly similar - with one glaring exception:
Fullriver for their DC and FT series, and almost every other AGM made - has a maximum charge rate of 20%-40% of the C20 rating.
Concorde, for Sun Xtender and Lifeline publishes 2.5 x C20  but 5 x C20 is permissible under certain circumstances.  Yes, I am serious and speaking from industrial application experience. Same thing happens when you compare maximum load and voltage sag under load.

Does this mean that Fullriver is inferior? Certainly not, it merely illustrates that not all AGM's are created equal. Pure lead or not.

I have a very low opinion of some AGM's, but that would require a private conversation. I have seen one major manufacturer's AGM batteries dissected in a battery lab. Some that were stamped Made in USA had core guts that clearly and identically match some cheap imported stuff. Gee, I wonder why they don't push that part of their product line. 

Marc

"Fullriver for their DC and FT series, and almost every other AGM made - has a maximum charge rate of 20%-40% of the C20 rating. "

I seem to have forgot what this means. Had to replace another battery this week. Looks like I may have to use the Fullrivers here. Truth is....I like them. They appear to be high quality batteries. Their self discharge rate was very low for being kept in a warehouse between 40F and 90F.

Do you think I could get a warranty from Graybar or...? They were made two years ago but it often takes a few months between manufacture and sale....may not matter on a warranty claim though...unless receipts are produced.

I bought 10 and may use 8 on a 48 volt system.

softdown

Never let it be said that our host lacks a sense of humor. Just found this little gem while perusing their expansions on batteries: "Flooded may be standard, with removable caps, or the so-called "maintenance free" (that means they are designed to die one week after the warranty runs out)"

Then this: "we have a large set of surplus telephone batteries that sees only occasional (10-15 times per year) heavy service that were just replace after 35+ years"     35 years....let that sink in.

softdown

This is some great, really great, battery information from this site:

Deep Cycle Battery Frequently Asked Questions

The links below are on this page - you can also just scroll down if you want to read them all.

This entire page is copyright 1998-2014 by Northern Arizona Wind & Sun. Please do not use without prior permission.

• What is a Battery?
• Types of Batteries
• Battery Lifespan
• Starting, Marine, or Deep Cycle?
• Deep Cycle Battery as a Starting Battery?
• What Batteries are made of
• Industrial Deep Cycle Batteries (fork lift type)
• Sealed Batteries
• Battery Size Codes
• Gel Cells (Gelled Electrolyte) (and why we don't like them)
• AGM Batteries (and why we do like them)
• Temperature Effects
• Cycles vs Lifespan
• Amp-Hours - what are they?
• Battery Voltages
• Battery Charging (Here is where we get into the real meat)
• Charge Controllers (for wind/solar)
• Mini Factoids - Some small facts about batteries

The subject of batteries could take up many pages. All we have room for here is a basic overview of batteries commonly used with photovoltaic power systems. These are nearly all various variations of Lead-Acid batteries. For a very brief discussion on the advantages and disadvantages of these and other types of batteries, such as NiCad, NiFe (Nickel-Iron), etc. go to our Batteries for Deep Cycle Applications page. These are sometimes referred to as "deep discharge" or "deep cell" batteries. The correct term is deep cycle.

A printable version of this page will be available in Adobe PDF format when we finish updating this page for downloading and printing: Most of the charts have small images for faster downloading. To see the full size picture, just click on the small one.

Battery History

Although Alessandro Volta in Italy is usually credited with being the inventor of the modern battery (Silver-Zinc), ancient cells have been discovered in Sumerian ruins, origin around 250 BC.

The first evidence of batteries comes from archaeological digs in Baghdad, Iraq. This first "battery" was dated to around 250 B.C. and may have been used in simple operations to electroplate objects with a thin layer of metal, much like the process used now to plate inexpensive gold and silver jewelry. Possibly one of the first uses for batteries, although there is some dispute among scholars. Wikipedia entry for Baghdad Battery.

Batteries were re-discovered much later by Alessandro Volta after which the unit of electrical potential was named, the volt. The jar was found in Khujut Rabu just outside Baghdad and is composed of a clay jar with a stopper made of asphalt. Sticking through the asphalt is an iron rod surrounded by a copper cylinder. When filled with vinegar - or any other electrolytic solution - the jar produces about 1.1 volts.

What is a Battery?

A battery, in concept, can be any device that stores energy for later use. A rock, pushed to the top of a hill, can be considered a kind of battery, since the energy used to push it up the hill (chemical energy, from muscles or combustion engines) is converted and stored as potential kinetic energy at the top of the hill. Later, that energy is released as kinetic and thermal energy when the rock rolls down the hill. Not real practical for everyday use though.

Common use of the word, "battery" in electrical terms, is limited to an electrochemical device that converts chemical energy into electricity, by a galvanic cell. A galvanic cell is a fairly simple device consisting of two electrodes of different metals or metal compounds (an anode and a cathode) and an electrolyte (usually acid, but some are alkaline) solution. A "Battery" is two or more of those cells in series, although many types of single cells are usually referred to as batteries - such as flashlight batteries.

As noted above, a battery is an electrical storage device. Batteries do not make electricity, they store it, just as a water tank stores water for future use. As chemicals in the battery change, electrical energy is stored or released. In rechargeable batteries this process can be repeated many times. Batteries are not 100% efficient - some energy is lost as heat and chemical reactions when charging and discharging. If you use 1000 watts from a battery, it might take 1050 or 1250 watts or more to fully recharge it.

Had to chop to fit...............

Marc Kurth

The 7 year warranty covers batteries that were first sold after September 1, 2014 and only covers the original purchaser - non transferable.Their warranty protects the user against actual manufacturing/materials defects. Here is a copy of their warranty:http://marckurth.com/7_year_warranty.pdf

Performance characteristics for new batteries: http://marckurth.com/dc-series-12.pdf
Installation/operation manual with a lot of good info: http://marckurth.com/fullriver%20oandm.pdf
 
Fullriver specifies a recommended charge rate of 20 amps per hundred amp hours of battery, based on the 20 hour rate - but they allow up to 35 amps/hundred.

If I had those batteries:
I would first charge them at 14.8v to 15.0v until they were only drawing about 2-3 amps, then float for a full 24 hours at 13.8v.;
Then I would discharge them to 11.0v at a 25-50 amp rate, then charge back and float as above.

Last step would be to do a capacity test with a constant 25 A load, down to 10.5v. If they came up short on capacity, I would give them constant current charge in order to achieve a controlled over-charge -- sort of an equalization.
http://marckurth.com/fullriver-charging.pdf

Marc

softdown

 

"The recommended bulk current is 20% of the 20 Hr. AH capacity or 0.20 x C20

(20 Hr. capacity in AH).

Example:

DC115-12 is rated at 115AH @ 20 Hrs.

The recommended bulk current is 0.20 x 115 = 23 Amps"

With eight 260Ah 12V batteries in a 48V string...I am thinking 520 x .20 = 104 amps. I can't make near that much power with 16 of my 180 watt panels. *Relaxes*

Marc Kurth

softdown said:

 

"The recommended bulk current is 20% of the 20 Hr. AH capacity or 0.20 x C20

(20 Hr. capacity in AH).

Example:

DC115-12 is rated at 115AH @ 20 Hrs.

The recommended bulk current is 0.20 x 115 = 23 Amps"

With eight 260Ah 12V batteries in a 48V string...I am thinking 520 x .20 = 104 amps. I can't make near that much power with 16 of my 180 watt panels. *Relaxes*

Yes.

And for your 8 batteries configured in (2) 48v strings, the maximum charge rate is .35 x 520 = 182 amps per hour.

Remember that these numbers are for this particular battery manufacturer's design. Some are more limited, some can go several times higher. All batteries are not cut from the same cloth.

Marc

Dave Angelini

I never said anything about suitable for cabins. Please do not misquote me!