Many people recommend 2 Trojan 6volt golf cart batteries as preferable to a single 4D battery. What do you see as the pros and cons of this approach?
6volt Golf Cart batteries
- Thread starter GWG
- Start date
This doesn't address the typical power requirements on a 40 ft boat which usually requires more amp-hrs than 2 -6v batteries can supply.
No one suggesting having only one battery aboard.. Question was compare one 4D to two golf cart batts for maybe half of your battery capacity.. They are comparable in amp hours.. the golf carts provide around 200 as do the 4D's the cost for two golf cart batts is about $250.. the 4D about $350-400.. The individual 6V batts weigh a lot less than the single 4D so they are easier to install and remove, but ya do have to move more parts.. There are 6 lead acid cells in each type (3 in each cart batt, 6 in the 4D)..so I think failure chance is not measurably different..
EDIT ; Change 8D to 4D .. was working with a bud who was using 8D's..
EDIT ; Change 8D to 4D .. was working with a bud who was using 8D's..
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Flooded 4D's are usually not a true "deep cycle" battery they are usually commercial starting batteries or a hybrid dual purpose battery designed to start trucks & buses and supply some light DC loads.
There are only a hand full of actual deep cycle 4D's made and they are quite expensive. Be very wary of off branded & especially "stickered" 4D's that claim to be deep cycle or even "dual purpose", this is most often hog wash. These labels / stickers are often applied by battery distributors or re-sellers and not by the actual battery manufacturer. Also be very careful with 4D's not rated in Ah capacity at the 20 hour rate. If all they show is CCA/MCA or "RC" reserve capacity this is usually a bad sign. No labeled Ah capacity is often a very strong indication they are not "deep cycling" batteries.
If I had a dime for every time I have seen the Deka 4D commercial STARTING battery labeled as deep cycle or even a hybrid dual purpose battery I could be retired. Deka does not make a deep cycle flooded 4D battery. This however does not stop distributors from mislabeling them and telling customers they are a "deep cycle" battery.
Soem manufacturers have even stopped producing them altogether. The big trucking industry is rapidly moving away from them due to OSHA issues and instead favoring Group 31's in parallel.
If anyone other than Rolls or Dyno Battery is telling you they have a 4D or 8D flooded deep cycle please research this and ask them for cycle data that compares to their GC2 or GC12 deep cycle golf car batteries..
You simply don't find this level of dishonest labeling in 6V GC2 golf cart batteries.
Dyno Battery, as mentioned, does make a deep cycle 4D but they can be tough to find and are more expensive than two 6V's...
4D's are cheap to install for builders and they normally last beyond the warranty period, which is all they really care about.. They are usually dropped into the boat by crane so they really don't care about your back problems...They also look big at boat shows which can be a selling feature to the less-schooled boat buyer.. Most production boat builders also won't generally install 6V batteries due to confusion on the customer end. "Why do I have 6V batteries on a 12V boat???" , so builders are left with 12V batteries and the 4D's and 8D's certainly look impressive at boat shows. performs impressively, not so much..
In any case where a 6V battery would fit, height wise, on a sailboat, I would always opt for 6V batteries over a 4D or 8D.. Even if 6V batteries won't fit height wise, I opt for group 31's or 27's over 4D's every day of the week due to ease of fitment..
6V GC2 batteries are specifically designed for deep cycling, cost less per Ah, and will give many, many more cycles before dying. They also tend to take charging abuse better due to the thicker plates.
You don't need to buy Trojan's to get good quality 6V GC2 batteries as this is a very, very competitive market and there are lots of players in it from Trojan to Deka, Superior, Crown, US Battery etc.... Many of these batteries get relabeled and sold for even less than the companies own branded battery.
You can also usually fit more Ah's per sq in of floor space with 6V GC2's. The average 4D is somewhere between 140 and 200 Ah's in capacity and is approx 21"L by 8.25"W. Two 6V GC2 batteries take up 20.75"L X 7.125" wide and give 225 - 245Ah's of capacity....
Ah's however are not the only good measure of a battery. Buyers very often don't take cycle life into account, and they should.
As an example Trojan Battery rates their own 12V "deep cycle" (automotive format batteries G-24, 27 & 31) at HALF the cycles as their T105/GC2 or their 12V GC12 battery... HALF the cycle life.....!
Two Trojan SCS 225's, which are 12V group 31's deep cycle batteries, will give you 260Ah's of capacity. This is the same Ah capacity as a pair of 6V T-145's. The T145 or T105 however will deliver about double the number of cycles as rated by Trojan in their lab..
Same Ah capacity yet double the factory rated lab life. DOUBLE.....
Trojan does not even produce a 4D or 8D flooded battery. Good for them!The only place I see any sort of a need for a 4D or 8D is on very large (Cat's, Cummins, Mann's, Deer's etc....) diesel engines for starting purposes. We simply don't need that cranking ability on sailboats. Even two G-31 batteries can easily exceed the cranking performance of an 8D..
Even when I had a massive Cummins, on our power boat, I still started it with two T105's, even in the middle of February..
The question was about 4D's as I read it.....??
This is a Deka GC15 relabeled as a Duracell EGC2. It is a true deep cycling golf cart GC2 battery. They are rated at 230Ah's for $88.74 at Sam's Club..... That comes out to just 77¢ per Ah @ 12V, and we've not even taken the extra cycling life into account which drives the savings between a 4D and a true deep cycle battery even further...
6volt
My 07 H-36 came with 2 4D's and it was setup to switch to 2 banks and was OK first year until one went bad and few years later both needed to be replaced and the fact that we use a lot of 12volt power for many things.
So any way I now have 1 big bank with 4-6volt T-105's and so glad I do not have to deal with those big heavy 4-D's.
I really like my T-105's and got them at a good price from golf cart shop in Florida and they don't seem to need fluid as much as my 4-D's always needed.
Nick
My 07 H-36 came with 2 4D's and it was setup to switch to 2 banks and was OK first year until one went bad and few years later both needed to be replaced and the fact that we use a lot of 12volt power for many things.
So any way I now have 1 big bank with 4-6volt T-105's and so glad I do not have to deal with those big heavy 4-D's
.I really like my T-105's and got them at a good price from golf cart shop in Florida and they don't seem to need fluid as much as my 4-D's always needed.
Nick
Went from two 8D batteries to 4 Costco 6 volt golf cart batteries. Cost was around $100/battery in California.
Weight of each 8D was 136 lbs. Had to use a block and tackle to get them out. The golf cart batteries were 64 lbs each. I could carry those down below.
New battery boxes as one 8D battery was longer and shorter than two golf cart batteries.
Needed to fab battery cables to connect the 6 volt batteries together as the over the counter cables weren't of a large enough gauge. Don't remember the specific wire sizes.
Also one of the existing ground cables had to be replaced because the battery terminals were physically in a different location and one cable wasn't long enough to reach.
Last but not least two 12 volt 8D batteries at 136 lbs. each were considered two cores and wouldn't cover the four core charges of the four 6 volt batteries replacing them.
Weight of each 8D was 136 lbs. Had to use a block and tackle to get them out. The golf cart batteries were 64 lbs each. I could carry those down below.
New battery boxes as one 8D battery was longer and shorter than two golf cart batteries.
Needed to fab battery cables to connect the 6 volt batteries together as the over the counter cables weren't of a large enough gauge. Don't remember the specific wire sizes.
Also one of the existing ground cables had to be replaced because the battery terminals were physically in a different location and one cable wasn't long enough to reach.
Last but not least two 12 volt 8D batteries at 136 lbs. each were considered two cores and wouldn't cover the four core charges of the four 6 volt batteries replacing them.
It may be "pssible" that the "D" in 4D and 8D means: "Dual Purpose" and NOT "Deep Cycle." As mentioned before, NOT a great idea or choice for a deep cycle battery.
Maine Sail's description of the serious deficiencies of the 4 & 8 Ds is something he's written about before, but this writeup is one of the most definitive I've ever read.
Seems to me that anyone with those monster batteries who doesn't have a bad back is prone to developing one as soon as they have to replace one of those puppies!
Maine Sail's description of the serious deficiencies of the 4 & 8 Ds is something he's written about before, but this writeup is one of the most definitive I've ever read.
Seems to me that anyone with those monster batteries who doesn't have a bad back is prone to developing one as soon as they have to replace one of those puppies!