What is the logic using 6v batteries in series

[john61ct]

Any specific batteries you have on the tip of your tongue with those generous life spans?

Rolls/Surrette at the top, U.S. Battery, Concorde, Superior, Trojan, Crown and East Penn.

Note these make lines for different use cases, look specifically for deep cycle industrial or renewable energy.

Within that context, look at their cycles vs DoD charts; 2V, 6V, 12V likely doesn't matter, just size & weight decisions.

For AGM, Odyssey, Lifeline and Northstar. Firefly Oasis, but only for PSOC abuse situations.

Sourcing good value golf cart batteries from Sam's, Costco, Walmart, etc., is great if you have access to those stores.

Out of those, Sam's is head and shoulders above the others, made by East Penn.

 

[john61ct]

I've been unable to find the proper graphs for Trojan, but in general the golf cart batteries appear to offer about 600 cycles @ 80% DOD, 1500 cycles @ 40%DOD.

Don't rely on generalizations, contact tech support and get the model-specific charts. If that is hard for a given vendor, bad sign, move on to another one.

And if you're smart you will only once in a blue moon dip anywhere beyond 50% DoD, so that's the benchmark to use to compare.

Note the lab setups to get these charts varies wildly between mfg, so only use them to compare between models of one firm, never trust them to make a decision between vendors.

Other than the vendors mentioned by me above, and especially if overseas outside the top 20 developed countries

https://en.m.wikipedia.org/wiki/List_of_countries_by_inequality-adjusted_HDI

I would view such charts as pure fiction created by the firm's marketing department.

There may of course be exceptions.

 

[john61ct]

​2 x Sam's Club Energizer GC-2 deep cycle golf cart*batteries will store 208ah and cost $169 (locally) for the pair = *$0.81/ah, over 700 cycles = $0.0012 /ah/cycle

Spending more on known good marques is usually well worth it in the long term financially, as long as they're properly cared for.

But likely not if you're going to sell the boat before the investment will be recouped.

 

[Larry M]

for me, 220 ah/$320 for 2 Trojan golf cart batts....that's less than $1.50 per ah...

That's numbers are high on the Trojans. I know they are a marketing chart but... We replaced 2 in January for $115/per at a golf cart store. Still a good bang for the buck and you can get them anywhere. We've bought them in the US, Mexico and Panama.

 

[FlyWright]

I think some of the most promising new batteries on TF are the carbon foam bank in PNW Boater/Moonfish's boat. They're pricey but Darren seems very pleased with them.

Here's a link to his write-up and video...

Pacific NW Boater - HOW-2 - TESTED: Carbon Foam Batteries

 

[psneeld]

I might have paid $120 at a golf cart place too...I was just too lazy to dig through my files, so I guessed high so some goober didn't bust my chops for being too low...

My point being that I have heard of guys buying Rolls and having issues with electric systems where they died long before expected and they swore they would never buy them again.

If it were a totally isolated incident...I wouldn't think twice...but it was several reliable reports and I don't know of many people who have them.

I am perfectly happy with golf cart batteries...if there were currently better bang for the buck batteries....why wouldn't they be in the bazillion golf carts out there?


I know there are better technology batteries, and batteries with unbelievable performance (for special applications)...but dollar for dollar in the application of general cruising...I remain unconvinced.


Unless you have a situation where getting to them is a bitc*.

 

[Mermaid]

I use four 8v batteries to make up a 32v bank. My DC system is 32v. I use golfcart batteries simply because I cannot lift the big 8v batteries. I have two battery banks and golfcart batteries are all I can physically do.

 

[Larry M]

I might have paid $120 at a golf cart place too...I was just too lazy to dig through my files, so I guessed high so some goober didfn't bust my chops for being too low...

My point being that I have heard of guys buying Rolls and having issues with electric systems where they died long before expected and they swore they would never buy them again.

If it were a totally isolated incident...I wouldn't think twice...but it was several reliable reports and I don't know of many people who have them.

I am perfectly happy with golf cart batteries...if there were currently better bang for the buck batteries....why wouldn't they be in the bazillion golf carts out there?

Scott: I agree and we like our GC's

Just because, you have a Rolls or Lifeline does that mean they have lower failure rates? What happens when you loose a battery in a 5-10 battery bank after 3 years? With golf cart, fla, we just go buy a new pair.

 

[Heron]

I am perfectly happy with golf cart batteries...if there were currently better bang for the buck batteries....why wouldn't they be in the bazillion golf carts out there?


.

Ditto.....When I built my bank, I bought Crown's from a local golf cart dealer...$105/each...

Golf & Electric Vehicle | Deep Cycle | Crown Battery

 

[FlyWright]

I installed a 6xGC bank of 624AH from Costco (208 AH Interstate GC2) for $85 each battery. That's $510 plus tax or less than $1.00 per AH.

My last house bank lasted 5 years and failed due to a charger failure that left them depleted during a long summer anchorage. Since then I've reduced loads (new fridge) and improved charging (Balmar alt and new shore charger) so I expect much better service from this bank. But even if I don't, I'm OK with 5 years out of a $500 bank.

 

[psneeld]

my point exactly...


golf cart house banks have been pleasing cruisers for decades at a reasonable cost.


I know few that will spring for the top end stuff...mainly because a bunch of smart people just aren't convinced they are worth it up front and taking the risk of all that money on something with no more guarantee on longevity than the golf cart batteries.

 

[dhays]

I installed a 6xGC bank of 624AH from Costco (208 AH Interstate GC2) for $85 each battery. That's $510 plus tax or less than $1.00 per AH.

My last house bank lasted 5 years and failed due to a charger failure that left them depleted during a long summer anchorage. Since then I've reduced loads (new fridge) and improved charging (Balmar alt and new shore charger) so I expect much better service from this bank. But even if I don't, I'm OK with 5 years out of a $500 bank.

I did the same on my sailboat. Replacing 2 x 4D batteries with 4 GC2s from Costco. Mine were only 200 Ah so a total of 400 Ah. Very inexpensive and I felt they would serve me well for at least 5 years.

Now, maybe if I had spent big bucks on Trojans I could have gotten 6-7 years? Who knows. As it turns out, I put the boat on the market to sell a year later. So while long term cost efficiency is important, I'm not sure I can really predict the future out more than a few years.

 

[john61ct]

I think some of the most promising new batteries on TF are the carbon foam bank in PNW Boater/Moonfish's boat.

Firefly Oasis are their own unique category of one.

Really only worth the $5/AH if you can't avoid chronic PSOC.

Not usually a problem on stinkpots, more for cruising / liveaboard sailors without room for enough solar and a genset.

But the tolerance of 80% DoD is a nice bonus.

G31 only, and back-ordered for months.

 

[Mako]

I'm trying to learn my lesson about doing things right the first time. However, I have to admit that our usage needs for this boat will be very limited these first 4-5 years versus afterwards (retirement). Now you all have me thinking that the best approach might be a bank of cheap Chinese golf cart batteries. Assuming an expected lifespan of 3 or 4 years then that would be perfect. They price on the market at about $1 per amp-hr.

Edit: The summer temperature here is generally about 120 degrees, so the life of these batteries will be killed over the next 4 years anyway.

 

[FlyWright]

My Costco batteries come with a 60 month (IIRC) full replacement warranty. I had a 12V G31 go weak after 6-8 months. The Costco gal told me that the battery was fully covered for 60 months...no receipt needed since they have the digital records.

It was replaced no questions asked.

 

[john61ct]

Sam's Club's are East Penn, much better than the other GC's.

No 12V from big box stores are true deep cycle, no matter what the label says.

My time is worth more than scamming guarantees, and it's completely unnecessary, just buy the right tool for the job in the first place.

 

[FF]

"The average boat here can carry enough inexpensive golf cart batteries to survive just fine. At some point, solar and wind is cheaper than more batteries."

AS batts age we are really just renting them between recyclings.

By far the least expensive method of lowering battery costs is a complete assessment of the battery use .

Lowering the batt AH requirement means fewer $ sitting and dieing slowly.

A buck a pound , a buck an AH ,will get golf carts that will do fine for 4-6 years,

UNLESS you KILL them!!!

That's why SOC meters were invented , to not kill them.

 

[psneeld]

But isn't that true of expensive batteries too?


Can't you kill any of them by feeding them the wrong charging voltage s, etc...?


Understanding batteries can be complicated and care/feeding critical.....if by chance, out of your control, are the expensive ones immune to damage?


Thus my rule of expensive versus "good enough".

 

[ranger58sb]

Regarding my particular selection, I have spec'd out an entire house-load package (solar, MPPT, batteries, inverters) from Everexceed in China. They are pricing now. For batteries I am referring to their "Tubular OPzS" 2 volt flooded cell. At 80% discharge they still have a life of over 2000 cycles.

I've been unable to find the proper graphs for Trojan, but in general the golf cart batteries appear to offer about 600 cycles @ 80% DOD, 1500 cycles @ 40%DOD.

If you have other info please share.

Others make 2V batteries. Lifeline, for instance. I haven't compared (can't use 'em, won't fit), but you might want to, just in case.

I found a life-cycle graph on the Trojan site; didn't pay perfect attention to other points on the "curve" (it was mostly straightline) but it read 1000 cycles to 50% DOD. Think that was for ALL their deep cycle batteries, not just the T-105s. Can't find it just now (of course), but it's on their site somewhere...

-Chris

 

[john61ct]

But isn't that true of expensive batteries too?

Can't you kill any of them by feeding them the wrong charging voltage s, etc...?

Understanding batteries can be complicated and care/feeding critical.....if by chance, out of your control, are the expensive ones immune to damage?

Thus my rule of expensive versus "good enough".

That is an excellent rule for a first bank when you're learning and more likely to murder them. Or if you are living month to month, or don't plan to keep the bank for decades.

But some want and can afford to reduce the odds of failure while off the grid, pay more for longevity, or lighter weight/less space.

Only worth it when you also have the knowledge, infrastructure and usage patterns to get good longevity.

 

[john61ct]

Others make 2V batteries. Lifeline, for instance. I haven't compared (can't use 'em, won't fit), but you might want to, just in case.

I found a life-cycle graph on the Trojan site; didn't pay perfect attention to other points on the "curve" (it was mostly straightline) but it read 1000 cycles to 50% DOD. Think that was for ALL their deep cycle batteries, not just the T-105s. Can't find it just now (of course), but it's on their site somewhere...

-Chris

No, each line, pretty sure each model, has its own specs. Contact tech support, their responsiveness should be part of your selection criteria.

 

[psneeld]

Who says most of us don't know about new tech or high end batteries and the necessary care and feeding? Or couldn't research them enough to know?

Not like you can only buy them with some lofty licensing agreement so they stay under warranty.


Also the point isn't about ME making a bad mistake....but stuff does happen and no one has really said how these batteries can overcome an unknown system failure.


Again, it's not that I don't think there are better setups than what the average Joe uses with golf carts....just all the literature and practical experience hasn't convinced the vast majority that it is dollar wise to switch over...just yet....unless you like to be cutting edge with its downfalls or have a special need.

 

[dhays]

Psneed, I am convinced that bang for buck, wet cells GC2s are the best value, at least for how I use my boat. I also don't think that I am all that unusual for a west coast boat. The boat stays most of its life sitting at a dock plugged into shore power. Lots of weekends and a few weeks a year away from shore power but that is it. Wet cells do fine with that type of use even with the occasional mistake or failure that causes a high DOD from time to time.

With this usage pattern, if it wasn't for the closed space that houses the batteries, and the limited access, I would go with GC2s. With the wet cells off gassing in an enclosed space with a combustion source, I am just not comfortable.

 

[psneeld]

And so, you pick what is best for you.


Not necessarily the typical boat enthusiast fresh back from the boat show with the newest toys.


great for some but not necessarily the "best" for everyone.


thanks for recognizing "balance" so often necessary in this forum.

 

[Seevee]

I installed a 6xGC bank of 624AH from Costco (208 AH Interstate GC2) for $85 each battery. That's $510 plus tax or less than $1.00 per AH.

My last house bank lasted 5 years and failed due to a charger failure that left them depleted during a long summer anchorage. Since then I've reduced loads (new fridge) and improved charging (Balmar alt and new shore charger) so I expect much better service from this bank. But even if I don't, I'm OK with 5 years out of a $500 bank.

FlyWright,
Do you by chance have a link for those batteries at Cosco? I've search their web site many ways and can't find them.

 

[Larry M]

https://www.costco.com/automotive-batteries.html

Not all Costcos carry a large selection.

 

[john61ct]

Sam's Club's Duracell 6Vs are made by East Penn, and are **much** better than the other GC's available through Walmart or other mass retail.

And no more expensive

 

[MVNoPlans]

I use these: https://www.batteriesplus.com/replacement/battery/trojan/t105/sligc145ut
255 AH and about 10 pounds heavier than the Trojan 105. Not cheap, but there is always a coupon available knocking $20 off the price. I previously used the Interstate 6V from Costco. No complaints either way. Just decided to go beefier since my daughter like to open the fridge and watch movies.

 

[psneeld]

Here is just one of many reviews I got by googling "best golf cart battery"...

Deka Pro Master Golf Cart Batteries are also an excellent battery. We used them for not only golf carts that went 10 mph but for Nev’s that went 25 mph. We found them to be just a level below the Trojans but the price point was much better.

Pretty universal and out of the 3 golf cart companies I have bought from, all 3 carried Trojans and or USA batreries,, the most popular here. None carried the Dekas, but they are a good battery for their price.

 

[dhays]

FlyWright,

Do you by chance have a link for those batteries at Cosco? I've search their web site many ways and can't find them.

Costco's website is terrible. You just need to go to your local store and see what they have. I saw plenty of them at the Gig Harbor Costco a couple weeks ago.