Help with batteries: TWO lead 4Ds or ONE gel 8D.

[zeehag]

d8 weigh in at 160 not 120 pounds. golf cart batts ar eliftable by me--less than 70 pounds.
durability of golf cart batts---i have had em lasting, normally, up to 10 yrs. my last set on this boat was 10 yrs before i replaced them. regular maintenance and charging properly is important.
dont think there are no d8 deep cycle..lol they are everywhere--just impractical as hell due to size and impressive weight--i caall em 3 man and a boy batts, as that is how many it takes to replace em. each kind of battery has ee=deep cycle and cranking availability. must read fine print.
as for deep cycle vs cranking batts--i prefer to use deep cycle in both and all banks as they do have a better longevity factor and i use both banks as house. yes especially when cruising..with panels for regular recharging, depending on use. cranking batts are a pita, in my book. they dont last long(3 yrs approx, give or take) and they are only for one use. all must have more than one use on my boat, including batteries.
i have been stuck in pair a dice here for a lil over a year--- and finally i am reinstalling my newly awesomely purpuk(sorry beni) engine--it was mechanix choice the color, so isnt my call..lol...
as for mechanics in barra denavidad--i have found a real good guy. you must bring interpreter or know spanish..lol he is a maestro and not expensive. does excellent work and puts the gringo ripoff alleged mechanix in mexico to total shame.
when cruising in mexico, it is merely laziness that keeps gringos from finding decent mechanics. no english--not used. oh well. i defied that and hired THE maestro of diesels. yes i spoke with johnco here--he is a scam con and is not appropriate fro use as a repair guy here-- ripoff .. hire local and thrive. hire gringos here and be victimized.

best info you will get, ever-----
when you plan a cat ass trophic fail, make sure it is within a few miles of a major shipping port, as you will find decent repair guys. i am 20 miles north of manzanillo, a major shipping port

[hlev00]

Sorry if this is a repeat, but here us a really good site - http://batteryuniversity.com.

From what I've read in the thread it won't contradict advice you've gotten but there might more good info there for you.


Sent from my iPhone using Cruisers Sailing Forum

[masterolive]

Well After reading all of theses posts,
Ive decided to prepare the next few weeks to getting my boat ready for a new installation of "4" 6v golfcart batteries, and a second 100W RENOGY solar panel.

-First off, I spent all day visiting 5 automotive stores across the county and could only find prices from $95-120. My last stop was Orileys, being at the right place at the right time, an old-timer talked some "sense" into me by telling me to buy NAPA cause they where cheaper.
The manager at Orileys decided to price match it and would them to me for 85 instead of their $119 with a one year warranty, compared to NAPAS 90 day warrantee.

-Second, since I have to buy a pair, money has become an issue considering the cost for 6 would hit in/over the 500s, so even with a larger 6bat bank, I would be bottlenecked at my recharge capabilities with one solar panel.

Therefore after much re-reading and thought,
I think that "4" 6v bats for cabin,
my "2" deep cycle marine batts for engine,
and "2" 100w solar panels will be the most practical option for me, and we will have to force our consumption habits to THAT limitation and disregard using the fridge all the time.

I would rather spend 500+ for a more versatile option that has a solution, than plainly 6 batteries. As we continue to prepare for our voyage in December we may end up getting more financial support or make more money to add more batteries later.

I still have a few more questions now regarding the possible 4 golf car battery setup, Im wondering if I could take one of the two deep cycle batteries I already have, and add it to the golf cart bank, or would that be a bad idea to mix batteries?
(I am still referring to this page and soaking up as much info from these helpful links you are all providing me.)

[Stu Jackson]

Originally Posted by scherzoja

Stu, thank you again for all your help a few months back.

Glad to help, glad it helped. I read the Pearson material. Interesting, but seemingly, in many cases, too theoretical. Maine Sail developed his ideas in parallel with mine, two different coasts, 15 years ago.

The sbo thread is a LOT more realistic, same results.

Happy electrons.

[Stu Jackson]

You really don't need two 12V batteries for a reserve/start bank. Why lug around the lead? Find the one that's in the best shape (hydrometer - or you should know by now) and sell the other one.

[masterolive]

Originally Posted by Stu Jackson

You really don't need two 12V batteries for a reserve/start bank. Why lug around the lead? Find the one that's in the best shape (hydrometer - or you should know by now) and sell the other one.

They are both in good condition and where given to me by my father.
I would just give one back if there was nothing else I could do with it, so unless anyone has an Idea I guess Ill give one back when its time.

[Ex-Calif]

How is the start bank charged?

I am going with the Blueseas 7611 ACR - It advertises to lower the paralleling cut out. This means the batts are in the system to be used along with house a little longer.

If you engine starts easily this could be an option to get more utility out of two start batts.

http://assets.bluesea.com/files/reso.../ChooseACR.pdf

About $80 on amazon

http://www.amazon.com/Blue-Sea-Syste...s=bluesea+7611

[ranger58sb]

Originally Posted by masterolive

-Second, since I have to buy a pair, money has become an issue considering the cost for 6 would hit in/over the 500s, so even with a larger 6bat bank, I would be bottlenecked at my recharge capabilities with one solar panel.

Therefore after much re-reading and thought,
I think that "4" 6v bats for cabin,
my "2" deep cycle marine batts for engine,
and "2" 100w solar panels will be the most practical option for me, and we will have to force our consumption habits to THAT limitation and disregard using the fridge all the time.

I would rather spend 500+ for a more versatile option that has a solution, than plainly 6 batteries. As we continue to prepare for our voyage in December we may end up getting more financial support or make more money to add more batteries later.

I still have a few more questions now regarding the possible 4 golf car battery setup, Im wondering if I could take one of the two deep cycle batteries I already have, and add it to the golf cart bank, or would that be a bad idea to mix batteries?

Originally Posted by Stu Jackson

You really don't need two 12V batteries for a reserve/start bank. Why lug around the lead? Find the one that's in the best shape (hydrometer - or you should know by now) and sell the other one.

Originally Posted by masterolive

They are both in good condition and where given to me by my father.
I would just give one back if there was nothing else I could do with it, so unless anyone has an Idea I guess Ill give one back when its time.

Common recommendations are that all batteries in a given bank be the same chemistry (flooded lead acid, AGM, gel, etc.), type (deep cycle, dual purpose, starting), age... and some also say size.

Perhaps another possibility for your consideration is to sell BOTH of your current "deep cycle?" starting batteries, replace with a single starting battery, and use what's left to fund at least part of a third pair of 6v batteries for your house.

Even if you get "more financial support or make more money to add more batteries later" sometime down the road, adding a third pair of 6v batteries at that time may not be optimal.

-Chris

[Maine Sail]

You really need to stop looking at batteries based on physical size and look at the "intended" use.

The only 4D & 8D batteries I am aware of, marketed in the US, that are actually available in a true "deep cycle", are the following:

*Lifeline AGM 4D & 8D
*Dyno 4D & 8D Deep Cycle
*Deka / East Penn Gel 4D & 8D (private labeled to many other brands)
*Trojan 8D GEL

I may have missed one but have not had my coffee yet.. Every other 4D or 8D battery out there is really a dual purpose truck battery NOT a true deep cycle battery.. 4D & 8D are best optimized for starting large diesels NOT cycling applications. They are also well optimized for keeping your spine surgeon in business.

There are big differences between typical 12V "marine batteries" and 6V deep cycle batteries in terms of cycle life, which is really what you want.

When buying batteries one must consider well beyond just Ah capacity. The most critical aspect to longevity will be the cycle life or how many cycles to 50% DOD you can pull off.

Most all 12V "deep cycle" marine batteries are imposters including top end brands like the Trojan 12V G-24/SCS-150, G-27/SCS-200 & G-31/SCS-225... They are not a true deep cycle battery and will yield far less cycles than a 6V GC2 battery. Trojan rates the SCS "deep cycle 12V line at about half the rated cycles as their own 6V T105 golf cart battery.

Some brands will claim more cycles than others in these group sizes but none compete directly with a GC2 in terms of cycle life. Cycle life data across brands needs to be ignored. There is no standard for rating batteries for cycle life so best to use data across a single manufacturer..

You are not just buying Ah capacity you are buying cycle life & expected durability and longevity.

There are 12V golf cart batteries such as the Trojan T1275, and they do have the same cycle life as a 6V, but they are also taller, like the 6V, and a built to use the same plates thickness as a GC2 battery. These are not your typical 4D, 8D, Group 31, 27 or 24 battery. Group 4D, 8D, 24, 27 & 31 batteries simply do not have the plate thickness a GC2 battery does with very few exceptions.

Deka/East Penn is perhaps the largest private labeler of marine batteries in the US, the NAPA GEL you linked to is an East Penn GEL battery (1000 lab rated rated cycles)..

There are more re-branded East Penn batteries out there than any other I see. One example the Deka / Sea Volt / West Marine line. In that line up you have starting, dual purpose and deep cycle G-24, 27 & 31 12V batteries which all share the same case. They simply do not offer a deep cycle 4D or 8D other than GEL, because it does not exist in the East Penn line up...

However, the G 24, 27 & 31 are only really deep cycle when compared to the starting or dual purpose batteries with which share the identical case. They are not deep cycle when compared to the GC2 or other true deep cycle batteries..

Here's the data across the Deka / East Penn / West Marine line up:

Flooded Batteries - Group 24, 27, 31 & 6V GC2

12V Starting - Cycles to 50% = Not Rated
12V Dual Purpose - Cycles to 50% = 200 (*4D & 8D flooded)
12V Deep Cycle - Cycles to 50% = 350
6V Golf Cart - Cycles to 50% = 700-1000


*Note: The above are LAB RATED cycles. Expect considerably less in the real world..


As you can see the 12V "deep cycle" battery is only a "deep cycle" when compared to the starting or dual purpose batteries it shares a case with. If you absolutely must buy a 12V Group 24, 27 or 31 buy the deep cycle version. If you absolutely must buy a 4D or 8D buy GEL or Lifeline AGM otherwise find a way to fit GC2 6V batteries. In many cases a 12V deep cycle is all that will fit. It is easy to see from the raw manufacturer data that these are NOT deep cycle when compared to a real deep cycle battery.

The only ones that have lab rated cycles for flooded 12V batteries the same or close, to their own brands 6V batteries, are Lifeline and the US Battery DCXC 12V series (at least those are the claims). In the real world I see US Batteries 6V GC2's outlast the 12V DCXC by a fair margin pretty consistently...

I know of no other brand, other than those listed above, that will rate their 4D, 8D, G-24, G-27 or G-31 flooded batteries at even half the cycles of their GC2 6V batteries.

The Deka / East Penn / WM product in 4D, 8D, 24,27 & 31 is less than half the rated cycles as their own 6V GC2 and these are by far the most popular marine batteries out there....

Don't just buy on Ah's buy on expected cycle life and buy a battery physically designed and intended for deep cycling not an imposter just labeled as a "deep cycle".......

[savoir]

When considering golf carts it is important to measure the available space in the battery box. Golf carts are taller than everything else and measure in at 10 1/2 - 11". Allow another 1" for the cables.

You may have to rebuild the battery box to make them fit and it could be that golf carts will not fit at all without a major and expensive cabinetry rebuild.

[accomplice]

As others have posted, there do exist deep cycle 4D and 8D batteries. I'm not saying they're better GC batteries, but they are *much* better for a house bank than starting or dual-purpose batteries.

I have a few things to add to the excellent advice others have given.

First, although deep cycle batteries can be discharged to 50%, they will last longer if only discharged to 60% (or even longer at 70%).


Second, charging is important, non-trivial and non-linear. Gensets and alternators may be great at getting from 60%-80% charge state, and ok from 80-90%, but IMHO they're not so good at the last 10%. I find solar excels for the last 10% -- I don't mind letting the silent and green solar charge the batteries for an extra N hours, but I don't want to listen to the diesel run and waste fuel. A smart alternator charge controller might help, but still you're limited in the rate that batteries will accept charge as they get full.

Third, (related to first and second) if you can afford the $, the weight and the space, larger battery banks are always better. Your usage requirements will determine the minimum bank size, but you will extend the # of cycles if you discharge them a lower %age and will decrease the charging time (per Ah) as you increase capacity.