Are GC2s really better than Grp 27s?

[newhaul]

Originally Posted by mitiempo

I don't think the VW comparison is valid. Comparing a complicated device with a computer that determines emissions uniquely under differing uses to what is basically a simple product like a battery doesn't make much sense.

This is very true vw intentionally skewed their emissions reports.to.decieve buyers.
Battery cycle life is not it is what they got with lab conditions . And I feel there is a correlation between lab numbers and real word numbers. . You likely wont get the same cycles.as the lab but it is a good indicator as to what ratio one can expect ok n the real world.

[ramblinrod]

Originally Posted by mitiempo

What really is a "Marine" battery? Most batteries labeled marine are the same as the rv of general use battery from many manufacturers.

For the most part there are batteries designed for starting, hybrid types, or deep cycling (GC2's for example, followed by L-16's (really a larger GC battery) and then the traction batteries for scrubbers and fork lifts, followed by the large 2 volt cells.

The golf industry is large enough to have a battery designed for them. Earlier in this thread Rod mentioned 50 golf carts at a course. Small courses often have 300+ carts, and in many places such as retirement communities in Florida they drive golf carts everywhere.

The marine industry is not large enough for use specific batteries from all manufacturers, and battery sizes for boats run from basic Grp 24,27,31 to GC's to 4D and 8D's - in other words all over the map.

RE: Golf courses

300 carts.

That's ~ 17 carts per hole.

I stand by my estimate of 50 carts per course average (2 per hole, with 14 spares).

RE: Battery use.

6Vdc lead acid batteries are not new.

These were used in cars and farm machinery before the industry standardized on 12 Vdc charging systems in the 1960s.

My first car (1961 VW bug, had a 6 Vdc system.)

There was no such thing as golf cars (first developed in 1932 and never took hold until 1950s) when 6Vdc batteries came to be.

According to Wikipedia, today, most golf cars are gasoline powered.

My best guess is that the marine/RV industry is significantly larger than the golf car industry.

[ramblinrod]

Originally Posted by newhaul

This is very true vw intentionally skewed their emissions reports.to.decieve buyers.
Battery cycle life is not it is what they got with lab conditions . And I feel there is a correlation between lab numbers and real word numbers. . You likely wont get the same cycles.as the lab but it is a good indicator as to what ratio one can expect ok n the real world.

I suspect that when a battery manufacturer is designing a battery in a lab, they optimize the design to perform well in lab conditions.

And for those manufacturers who don't publish cycle data, we have no idea how they perform. We can assume it will be similar to another product, but that assumption is mostly baseless and may be completely false.

Who has the scientific test data to prove that a GC2 handles partial state of charge better than a cheap grp 27?

Anybody?

Beuller?

Beuler?

We simply don't know.

We can "feel", "suspect", "assume" whatever we wish; we still don't know.

Hence the reason for starting the thread.

[GrowleyMonster]

Originally Posted by jcapo

Paid $470 for 6 GC2's yesterday at a golf cart dealer in Ormand Beach, FL. Deka GC10 same as Sam's Club. The golf cart guys always have good prices and they will deliver.

Wow thats a fantastic price! My propulsion bank of 8 Sams club Energizer GC2's cost me $85/ea, 3 years ago, and I thought I was getting a pretty good price on them.

[GrowleyMonster]

Three years in, my 48v bank of Sams Club GC2s is still going strong, and they were the best bang for the buck that I could find, with the best $/ah figure of any type or brand. I also like the form factor, which worked out really well for my installation. I had originally considered 8D or even 4D batteries. No way was I interested in a bank wired in series AND parallel... makes my head hurt just to think about it.

As already pointed out, there are some low usage situations where gp 27's do make sense. And the difference in charge cycles probably isn't all THAT much, given equal quality batteries. But golf cart batts are cheaper, that's a fact. For bigger banks, the "gotta replace two of them" just isn't so. My 6v batteries are in series. If one goes north on me, then I have a 42v bank, at least temporarily. No big deal. Just means I have to use my manual charger instead of the Worst Marine 4 bank smart charger. My dc/dc converter will cheerfully continue to provide juice for 12v house loads until I get down to I think 24v worth of batteries.

So really, a lot depends on the application.

I know this much... I am considering a second bank, to (at least) double my range without charging, and they will definitely be 6v batteries, probably more Sams GC2s. L16s would be great, but the GC2s are the cheapest per AmpHour and they have proven themselves, to me. I don't believe that gp27's priced the same per AmpHour would have lasted as long with no sign of aging. I have had two house banks of group 27s that I can remember, as well as house banks of other sizes of 12v batteries, (Never had 8D or 4D though) and all were at least showing their age at the three year mark. Had one bank that barely made two years, actually. Sure, they were el cheapo rebrands, but these Energizers are not meant to be high quality top shelf, either, and look how they are performing. They dont just keep the lights and a fan going, they make the boat go.

Switching to 6v golf cart batts is not going to end world hunger or close the ozone hole or fix The Donald's hair style or make you the very best person you can be or in fact meaningfully solve ANY of your problems, but you get more, for less, and I will testify to that. Don't expect miracles, but do expect to get a better deal, at the time of sale, and over the lifetime of the bank.

[ranger58sb]

Originally Posted by ramblinrod

Who has the scientific test data to prove that a GC2 handles partial state of charge better than a cheap grp 27?

I suspect PSOC is a whole 'nother discussion. Don't think anyone here has said anything about GC2s or G27s with PSOC in the same sentence?

And you probably know, MaineSail has also commented lots about lack of standardized testing ref PSOC, lack of manufacturer specs... over and above the previous issue of (mostly) currently published manufacturer specs but in perfect lab conditions.

-Chris

[pcmm]

Originally Posted by a64pilot

Funny thing is if you go to Sams club website and click on the link for Marine batteries, there won't be any 6V batteries, so apparently GC2's are not "marine" batteries.
Wanna bet this type of thing is why there are so many Group 27 batteries sold, cause they are "Marine" and everybody knows you have to have a marine battery to go in a boat.

If only People knew the truth! Deka OEM's ( and of course so do the others) for a bunch of brands. simply black boxes with different labels stuck on depending! I've seen the line where they stick on Westmarin labels on CG2's then stick on the Duracell labels for Sam's club... Difference one says "west marine" and you pay $240 per batt, the other says duracell and you pay $85 per batt. Easy math!

Trojan's aren't what they used to be. look at golf courses, they use less and less Trojan now, because the cost doesn't justify the difference.

[ramblinrod]

Originally Posted by ranger42c

I suspect PSOC is a whole 'nother discussion. Don't think anyone here has said anything about GC2s or G27s with PSOC in the same sentence?

And you probably know, MaineSail has also commented lots about lack of standardized testing ref PSOC, lack of manufacturer specs... over and above the previous issue of (mostly) currently published manufacturer specs but in perfect lab conditions.

-Chris

Actually PSOC IS this discussion. We don't operate our boats under lab conditions. We operate our boats in real life conditions.

The original question was, "Are GC2s really better than Grp 27s", not "Are GC2s better than Grp 27s...in the lab?"

Frankly, I don't care what batteries do in the lab, until I can ascertain that there is some logical correlation between what they do in the lab and what they do in real life. I can't.

We simply don't have that, and based on my background and experience, I would never jump to the conclusion that there is one.

In real life, when away from shore power, batteries don't get charged to 100% every day. In fact, they may rarely get charged to 100%.

For all we know, a battery that gets 2.5 times more cycles in the lab, may be more susceptible to PSOC issues and end up getting 1/2 the cycles of comparators in real life.

This is just one "real life" factor, there are likely many more that will have a bearing on "real life", some we can predict, and some we have never thought of.

And yes, I know others have ranted about the lack of industry standard battery specifications.

For all of the batteries sold, very few have ANY published cycle specs; generally only the high quality (ie. most expensive) brands.

The percentage of these batteries sold compared to the incredible volume of lesser batteries is very low, and there is no logical reason to assume that any correlation between battery designs of one high quality brand and another, let alone a much lesser brand exists; yet I see it stated all the time that 6Vdc are better than Grp 27s.

We can also read in the Compass Marine article, that dock speak is useless in this matter.

So if we trust that article, and the premises behind it, then we should never accept any statement, "I switched from x to y and they are so much better".

Every time I have heard this statement, I have found that there was no scientific basis, and there were so many variables introduced simultaneously that nobody in their right mind could correlate the performance improvement directly with the battery change.

The state of the electrical system on most cruising boats is very dynamic, with improvements in system composition and maintenance changing all the time, usually for the better.

This is what I see with battery change outs all the time. Someone switches from 12 Vdc to 6 Vdc, and at the same time increases battery capacity by 100%, improves wiring, installs a better charger, adds solar and wind, a high output smart alternator, and changes lighting from incandescent to LED.

The batteries last 2 years longer and they state, " I changed from 12Vdc to 6Vdc and the new batteries last twice as long."

How much of the improvement was due to battery design? Any? Could the new batteries actually be worse, but there are so many other improvements the net result is an improvement?

Of course, hence the reason for this thread.

[ramblinrod]

Originally Posted by pcmm

Trojan's aren't what they used to be. look at golf courses, they use less and less Trojan now, because the cost doesn't justify the difference.

Do you have any verifiable evidence that the performance of Trojans is less now than what it once was?

Or are you assuming this because you have seen golf courses change brands.

Could it be that after years of comparison, they have discovered that Trojans simply aren't any better in "real life" application, and never have been?

Could it be that even though Trojan's are in fact better, but there was pressure to reduce the maintenance budget, and one short term method for that specific year was to change to a lesser quality battery, whose financial impact increase wouldn't be realized until 2 years out when they started failing earlier than the premium brand?

What are the chances when the maintenance manager decides to switch to a lower cost brand to meet budget targets, that 2 years later, after finding the inferior quality, they will then request a maintenance budget increase to switch back to the previous brand, or just proclaim, "Batteries ain't what they used to be"?

As a very large and powerful industry segment, boaters should stop "gossiping" about battery performance, and start serious performance testing, and holding battery manufacturers accountable for the real performance of their products. This could also have health and environmental implications. I just read where an estimated 12,000 people per year in developing countries (where all the dead North American batteries go) die due to hazards from battery recycling.

[ramblinrod]

Originally Posted by pcmm

Trojan's aren't what they used to be. look at golf courses, they use less and less Trojan now, because the cost doesn't justify the difference.

On the other hand, maybe Trojans aren't what they used to be, and this is why they stopped publishing lab cycle data. Maybe they haven't tested the new design. Maybe they have and it is inferior and they don't want to make this public knowledge, with the hope that prospective purchasers will continue to make decisions based on the old data.

Who knows?

If Trojan doesn't know, you can be dang sure J.Q. Boater doesn't have a clew.

[mitiempo]

My best guess is that the marine/RV industry is significantly larger than the golf car industry.[/QUOTE]

And if they all used the same type of battery that might make sense - but they don't, they're all over the map. Golf carts are much more consistent as far as battery type used.

There is a golf course in Surrey that has electric carts. At my nephew's wedding reception in the summer I counted over 200 parked carts while many were on the course.

[mitiempo]

Originally Posted by ramblinrod

I suspect that when a battery manufacturer is designing a battery in a lab, they optimize the design to perform well in lab conditions.

Lab conditions are merely perfect draw and immediate recharge in proper temperatures. The farther one strays from these circumstances the farther from lab conditions you end up. The cycle relationship between Grp 27 and GC's should be similar if not the same.

[newhaul]

Originally Posted by mitiempo

My best guess is that the marine/RV industry is significantly larger than the golf car industry.

And if they all used the same type of battery that might make sense - but they don't, they're all over the map. Golf carts are much more consistent as far as battery type used.

There is a golf course in Surrey that has electric carts. At my nephew's wedding reception in the summer I counted over 200 parked carts while many were on the course.[/QUOTE]

Have a Yamaha dealer and repair facility a few miles away from here . They have well in excess of 500 carts there they also do the maintance for most if not all of the local courses carts. I will stop in one of these days and ask them what batteries they use and recommend.

[mitiempo]

Originally Posted by pcmm

Trojan's aren't what they used to be. look at golf courses, they use less and less Trojan now, because the cost doesn't justify the difference.

Trojans are what they used to be, but other manufacturers got better, at lower prices. Less golf courses use Trojan now than they used to.

[mitiempo]

Rod

What anchor do you use?