Costco GC2 Batts

[jake2250]

Well, One of my 4 year 4 month old GC2s from Costco just coughed up a cell during a cold Coast camp trip!! Sure I could buy another $86 Batt,, but I would still have a 4+ year old one..
Ordered two T105 Trojans,,, hopefully I wont report back for five or more years!!

[BFL13]

Whatever, you want an adjustable for your 12s and another one for your 48s. (If there is one for 48s)

I agree money is an issue with these things. If you are something of an electrician, you can spend less and do your own mods to get a decent pot knob, wire terminal size, and cooling fan, like landyacht did with his.

Otherwise, you have to pay the going price to get it all done up as is from delivery.

[hammick]

BFL13 wrote:

hammick wrote:
You would think Interstate would enlist somebody to make a charger for their batteries. I don't even know if the 48v golf cart chargers can meet their specs. When I called interstate I spent a lot of time on hold to finally have a recommendation of a Schumacher automobile charger. Clearly that charger couldn't get the job done.

The adjustable voltage charger is the way to go. PowerMax makes them for 12v They make ordinary chargers for 24 and 48. Don't have info on other Brands, sorry.

http://powermaxconverters.com/products/

The Powermax adjustable looks very nice but is about five times the price of the Megawatt.

[BFL13]

hammick wrote:
You would think Interstate would enlist somebody to make a charger for their batteries. I don't even know if the 48v golf cart chargers can meet their specs. When I called interstate I spent a lot of time on hold to finally have a recommendation of a Schumacher automobile charger. Clearly that charger couldn't get the job done.

The adjustable voltage charger is the way to go. PowerMax makes them for 12v They make ordinary chargers for 24 and 48. Don't have info on other Brands, sorry.

http://powermaxconverters.com/products/

[hammick]

You would think Interstate would enlist somebody to make a charger for their batteries. I don't even know if the 48v golf cart chargers can meet their specs. When I called interstate I spent a lot of time on hold to finally have a recommendation of a Schumacher automobile charger. Clearly that charger couldn't get the job done.

[BFL13]

"agree with BFL13 that with enough time 14.8 (or even less) will work."

Not much less though. My first set of 6s never got into the green on hydrometer just using the 13.8v converter no matter how long they did that.

. Only got them properly charged after I got a charger that would do 14s. ( A Vector portable smart charger) AFAIK you must get them above "gassing voltage" or the batts are doomed.

[grizzzman]

Double post

[grizzzman]

hammick wrote:
A few clarifications on the Costco batteries. Absorb spec is 7.65v so 15.3v for a 12v system. Float is 13.4v. My specific gravity is also 1.300 with both of my hydrometers.

I'm not going to try an convince anyone or myself that the Interstate GC2 batteries are as good as the Trojans. But for recreational boondocking they work great for me. They are cheap and readily available. Plus the filler cap design makes it super convenient for a quick check of fluid level or a dip with the hydrometer.

Trojan also requires a high equalization voltage so if you have Trojans you also have to give some thought to keeping them maintained.

I have my solar charge controller set to absorb at 15.3v for one hour and then float at 13.4 If camping during a nice long summer sun sometimes I will up the absorption time and the float voltage to make sure they get a nice long charge.

And let's fact it. If you have the Interstate batteries you either self educate yourself about proper battery charging or they will have a short life. The dealers and people selling the stuff will all tell you that 15.3v is crazy and not necessary.

So if it wasn't for my Interstates I wouldn't know anything about Megawatts and Meanwells and would have missed the brain exercises trying to decipher Mex's babble.

A good way to learn this stuff is with a couple of cheap Costco batteries and a Solar charge controller. It gave me the confidence to design, purchase and self install a 48v off grid solar system using a very expensive bank of Trojan batteries. My setup is working better than I could have ever hoped and I am confident I'm not killing my batteries.

Thanks for correcting my errors.
I also do not charge as they instruct. Absorb is set at 14.8. I allow the solar controller to put in 112 percent of what was used the night before. At this point the controller fires up a "finish absorb" at 15.3 (at a regulated low current value) 4 percent in my case. At this point the controller resets the amp counter to 100 percent. Then it drops to float.
I agree with BFL13 that with enough time 14.8 (or even less) will work.
But for me it is more important to hit "charged" daily as a goal.

I agree the costo's are a great value. In my case it was more batteries
or more solar....... Solar won. Next years project will likely be LFP talk about a spendy battery. A 100AH pack with hi/lo safety's will be what I spent on solar panels.
"Mex's babble." Don't get me wrong, MEX is a great guy with a lot to give. But that describes his writing style aptly :R

[3_tons]

pianotuna wrote:
What inverter are you using? What is the wattage when the air is running? Voltage drop on the batteries?

3 tons wrote:
Well, since I never drive the camper over the greens, and can run my 11k air conditioner for short periods (30 to 60 min, depending on SOC) off of two 208 a/hr Costco $85 GCs, I believe thay are a serious alternative to the 'better' brands....JMO from actual personal experience....

3 tons

The inverter is a Xantrex pass-thru ProSine 2.0 with 4500 surge watts....Using 4 ought 7' round-trip cables...This is in concert with 440w of solar (300 MPPT; 140 PWM - still a net loss...) starting at 95-100% SOC (per LinkLite shunt metering)...Can't recall the watts or volts because its been a few years since I've checked...Have run ac easily for 30-60 min periods, this with fan on low speed and compressor typically cycling approx 75% run time (typically compressor run time the main variable), in full sunlight have (inadvertantly) run for as long as two hrs to 50% SOC (Oops)...One thing I want to avoid is never let the Batts to drop below 60-55% SOC...

3 tons

[hammick]

A few clarifications on the Costco batteries. Absorb spec is 7.65v so 15.3v for a 12v system. Float is 13.4v. My specific gravity is also 1.300 with both of my hydrometers.

I'm not going to try an convince anyone or myself that the Interstate GC2 batteries are as good as the Trojans. But for recreational boondocking they work great for me. They are cheap and readily available. Plus the filler cap design makes it super convenient for a quick check of fluid level or a dip with the hydrometer.

Trojan also requires a high equalization voltage so if you have Trojans you also have to give some thought to keeping them maintained.

I have my solar charge controller set to absorb at 15.3v for one hour and then float at 13.4 If camping during a nice long summer sun sometimes I will up the absorption time and the float voltage to make sure they get a nice long charge.

And let's fact it. If you have the Interstate batteries you either self educate yourself about proper battery charging or they will have a short life. The dealers and people selling the stuff will all tell you that 15.3v is crazy and not necessary.

So if it wasn't for my Interstates I wouldn't know anything about Megawatts and Meanwells and would have missed the brain exercises trying to decipher Mex's babble.

A good way to learn this stuff is with a couple of cheap Costco batteries and a Solar charge controller. It gave me the confidence to design, purchase and self install a 48v off grid solar system using a very expensive bank of Trojan batteries. My setup is working better than I could have ever hoped and I am confident I'm not killing my batteries.

[BFL13]

I have posted this before, but it applies here too I think.

My almost 6 yr old Interstate 232AH 6s (GC2 XHD) are still apparently doing well, now down to 90% of original capacity by my last load test. I have no idea how many deep on them. Not a full timer, so not a huge number--maybe a 150? )

Once I get home from doing 50-90s away, I have always followed getting them to "full" (according to the charger) at 14.8 by giving them some time at 15.7 to get the SG up to "true full" (which was 1.300 when brand new, at 35F in Feb 2011)

Lately I have found that they will also reach "true full" SG if I leave that 14.8 on overnight and never do that 15.7 thing at the end.

It is all about how long you leave them at 14.8 after they are "full" (But aren't quite yet truly full.)

The trouble is leaving them at 14.8 so long lowers their water some, and I suppose does bad things to their plates. Anyway, it sure gets them "truly full." 🙂

[MEXICOWANDERER]

The average life of a properly cared for quality GC220 golf car service battery is 700 cycles.

Even under maintenance only conditions 52 months is quite enough to allow a 5% antimony battery to vigorously disagree with its new neighbor. There is one trick however than mustn't be allowed to believe it will automatically agree with the batteries and make them friends.

Connect the batteries in series. Six cells. No need to do this test disconnected but it is very necessary to isolate the linked batteries to chassis negative or positive. Six cells in series.

Charge both batteries to their max fill point.

Let them sit for a week after charging them. Then measure 3 cell voltage totals for both batteries - two voltage readings.

.15 fifteen one hundredths of a volt difference is the go-no-go line voltage limit. Then during the remaining lifespan of the old timer repeat this test every Spring.

People hate hydrometers. I dislike going to the dentist but I will be darned if I will suffer a toothache.

As long as those 2 batteries remain reasonably close in voltage and electrolyte density tests keep using old with new. The alternative of course is to purchase a second battery.

[mikestock]

jake2250 wrote:

Nunyadamn wrote:
I am pretty sure you could take it back to Costco for a replacement/refund. That's the best benefit of being a Costco member, they will take almost anything back.

Probably so, but the age factor and mixing old and new,, Five years is standard life of a battery so for the $42 difference in the two sets,, I will hope I get the better battery and be happier.

They never tested mine. I have a pair of starter batteries in my diesel truck. They sounded weak when cold weather came along. I took them both back and they never questioned me. Full replacement after 2-1/2 years. They even refunded the price increase that had occurred during the 2-1/2 years.

The real reason they failed was because I didn't drive the truck enough.

[MEXICOWANDERER]

Oooooo the boys are feeling the heat...

"Let's make it reeeeaaaal complicated so it impresses the guy who signs our checks"

That charging formula listed above is wholly, purely, totally, and absurdly asinine. How's that for directness?

Try as I might to simply the process to realistically attain full cell gravity along comes someone who reads idiot originated material then pontificates it as being "recommended".

I told you folks a few years ago these jerks were going to up cell electrolyte density to pull a pea and three walnut shells prestidigitation act on the public. If that 1.300 reading is from a known accurate hydrometer then the absurd has become reality.

Hybrid construction is a compromise. ALL TYPES OF BATTERY CONSTRUCTION ARE COMPROMISES. Clear? Antimony poisoning of lead dioxide negative plates can be controlled with float voltage control. This is not Toroid Fusion Containment level Science. Still clear?

The OPTIMUM metallurgy for a flooded deep cycle battery is 5% antimony positive and lead dioxide negative PURE VIRGIN LEAD PLATES. Electrolyte density temperature adjusted.

The 5% antimony construction demands unique maintenance, just as various other metallurgy demands their particular maintenance.

But the 5% antimony lead dioxide metallurgy yields by far the longest lived, and most durable flooded deep cycle battery. No we are not talking about car batteries. A deep cycle flooded battery must be represented by a CHART depicting depth of discharge versus number of expected cycles.

Run run run...

Try and get such a chart from a hybrid manufacturer. Oooooo they don't have them do they. Does Johnson Out Of Control or US Battery or any others have a life cycle chart for their low antimony batteries. Ooooooo why not?

If total kWh life cycle cost is ignored you become a victim not a smart consumer.

I am going to have to cut and paste to disk that absurd charging formula above. The original US Battery "Contains Miracle Selenium Additive" laugh-a-mania wore thin years ago.

Why not ask the Bozos (capitalized) exactly how they green their batteries. That ought to shut them up. Or ask them the purity content of the recycled Pb they use, citing SPECIFIC percentage of impurities.

There are few things I dislike more than Herb Tarlek driven idiots fearful of pink slips on Friay issuing bafflemwithbullshit hyperbole. You done struck a nerve.

[grizzzman]

let's have some fun shall we ? Say your battery bank is Interstate (Costco) CG2-RD at 208 AH 107 minute 75 AMP reserve rate. Let's look at the charging specs shall we? Charging amps at C/10 = 23.2. Bulk at 14.46 to 80 percent of SOC. Then absorb at 15.3 for 2 to 4 hours to 97% then float at 13.4. The resting voltage is 12.96 and specific gravity is 1.285 fully charged.(although every one I have dipped fully charged has been 1.300 specific gravity on new batteries.)

How many charger's that you know of can do this? (The one I use that does cost over $600) And you can count on one hand how many converter's can do this. (But you would need to chop off all your fingers and thumb to get the correct number ??)

Battery construction: Hybrid, It has a low antimony (under 2 percent) positive plates and calcium negative plates. So why is this construction important? A high antimony 5-6% battery will accept a charge real well if deeply discharged. If over charged or high float voltage, will cause the negative plate to be poisoned by antinomy. This cause's excessive water use and big self discharge. The advantages of a calcium battery are tolerance to heat, low water consumption and a low discharge rate.

So a Hybrid battery advantage would be lower self discharge (especially when new) slower negative plate antinomy poisoning from overcharging. Better in higher heat and lowered water consumption.
The disadvantage is it is more difficult to recharge during deep discharge. Less antinomy. Calcium creates a oxidation boundary layer on the negative plate during a deep discharge that resists the charging process. ( This is the reason for the higher absorb voltage) Also a higher specific gravity acid will give more AH for a given construction....... But at a cost of a higher plate corrosion rate.
So why would they build a Hybrid deep cycle? That's easy, "longer shelf life" (lower self discharge) and lower "warranty" issue's due to better tolerance to overcharging and antinomy poisoning.

There are other ways to charge that battery. A lot has to do with how it is discharged. (How many amps and DOD as well as frequency of discharge)

[pianotuna]

I could not agree more.

Once we get to more exotic technologies the same rule should apply. I'm intrigued by the new carbon foam jars. I must try to research them somehow.

MEXICOWANDERER wrote:
Again cents per kWh is the only intelligent way to measure a cyclable battery. Avoiding this calculation is bunk science and economics