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Battery choice

5K views 24 replies 11 participants last post by  camaraderie 
#1 ·
Hi Guys and Gals!

I need to replace my batteries and like all of us, I have space and weight constrains.
I'm projecting using in between 100 and 150 A/day and also planning to set up a 200 A alternator with AR 5 regulator..... what is the forum's suggestion?

1) 4- 6 V tall flooded at total of 740 A
2) 4 group 31 12V flooded total 620 A
3) 4/5 group 31 12V AGM at 420-525 A.

I'm partial to the AGM but wih the 6 V a get far more amps...but as usable as with the AGMs?


thank you
 
#2 ·
All good choices and personal preference certainly plays a part in what you finally decide. Given the AH needs to stated, check out the Torjan L16Ts which might give you the longest life presuming your okay with monitoring fluid levels frequently. Everybody has their favorite theory on whether or not AGMs are worth it.
 
#3 ·
Ruiz..First, I might rethink that 200A alternator. That will bequite a strain on most engines and 100-125 should be plenty for your needs. You don't want to be using the engine for charging your bateries unless underway anyhow.

I don't know why 4 AGM's should give you less amp hours than 4 flooded. The mfr. specs may vary between brands and they may rate agressively or conservatively. As a class, Group 31's should deliver the same amps sso you may just need to look at a different brand or determine the "rating" system but I would use 110AH as your average. I don't know HOW any flooded group 31 can deliver the 155A/H's you claim. That is a 4D rating!!
You don't spec out the 6V battery so I can look at it but I am thinking that you may be looking at a VERY different rating spec since each would have 155AH rating at 12V for what you say to be true. Those would have to be VERY big 6V batteries.
Do you have links to any of these products?
 
#5 ·
I suspect Ruiz knows that, and he's done his homework.

Four Trojan L16H's (420AH each) would give him 840AH at 12V. Four Trojan J305H's (335AH each) would give him 670AH at 12v. These are both "tall" 6V batteries. Lots of choices of these from other manufacturers as well.

Ruiz...

My preference would be to go with choice #1. I agree with the comment about rethinking the 200A alternator, because:

a) you don't need that much to charge a 700AH battery bank....100-120A would be sufficient; and

b) the problems of adequately belting at 200A alternator are magnified significantly over, e.g., a 120A alternator.

Bill
 
#7 ·
Thank you al of you for the support, I'm glad I joined this forum.

Few comments
1) the 6 V ad 12 V flooded are all fom Crown batteries which seem to have an excellent reputation.
2) Th 6 v are 16" high instead of the standard 9" average so there is the difference in capacity and also weight about 123 lb.
3) The capacity of 155 and 185 A is for their model CR 155 and CR 185 wich as the same dimensions as the type 31 so therefore I called them 31 to simplify the mail. ( look in the Crown battery site )

4) The AGM batteries mentioned are Lifeline which are suposed to be top notch West Coast made and standard equipment on upscale new boats. I do not know why their rated capacity is somewhat lower that the equivalent flooded, I assumed that is part of the technology etc.

5) The reason why I choosed or planning to, a 200 A alternator is based on Nigel Calder's reccomendation, his book and personal boat and he is considered the "guru" of electrics/electronics.

He has on board his 40 cruiser
-675 A agm's total in house plus 100 a starting AGM
-2 alternators ..1 for the starting battery (plus additional support) of 80 A and Balmar of 200 A. the first one with internal regulator and the 200 A with a AR 5 also from Balmar.
He supplements its power genration with a wind vane and 2 Siemens ( wattage unknwon presumabbly 75 W)

Let us remember that AGM do not have charging limit ( theoretically) while with flooded you do not want to go over 25/35 % of total capacity maximum.

Calder has all standard equipment on board a long range cruise, windlass, 12 V freezer and cooler, SSB, electronics, audio etc etc.

I hope it helps alo lke many of you, I am somewaht concerned about such a large alternator but it seems to be the way to gfo theses days, more eficient, less time running the engine a fairly medium charge ( good) etc.
althogh the power penalty is considerable azt close to 8 HP for the 200 A alone.
 
#8 ·
Thank you al of you for the support, I'm glad I joined this forum.

Few comments
1) the 6 V ad 12 V flooded are all fom Crown batteries which seem to have an excellent reputation.
2) Th 6 v are 16" high instead of the standard 9" average so there is the difference in capacity and also weight about 123 lb.
3) The capacity of 155 and 185 A is for their model CR 155 and CR 185 wich as the same dimensions as the type 31 so therefore I called them 31 to simplify the mail. ( look in the Crown battery site )

4) The AGM batteries mentioned are Lifeline which are suposed to be top notch West Coast made and standard equipment on upscale new boats. I do not know why their rated capacity is somewhat lower that the equivalent flooded, I assumed that is part of the technology etc.

5) The reason why I choosed or planning to, a 200 A alternator is based on Nigel Calder's reccomendation, his book and personal boat and he is considered the "guru" of electrics/electronics.

He has on board his 40 cruiser
-675 A agm's total in house plus 100 a starting AGM
-2 alternators ..1 for the starting battery (plus additional support) of 80 A and Balmar of 200 A. the first one with internal regulator and the 200 A with a AR 5 also from Balmar.
He supplements its power genration with a wind vane and 2 Siemens ( wattage unknwon presumabbly 75 W)

Let us remember that AGM do not have charging limit ( theoretically) while with flooded you do not want to go over 25/35 % of total capacity maximum.

Calder has all standard equipment on board a long range cruise, windlass, 12 V freezer and cooler, SSB, electronics, audio etc etc.

I hope it helps alo lke many of you, I am somewaht concerned about such a large alternator but it seems to be the way to gfo theses days, more eficient, less time running the engine a fairly medium charge ( good) etc.
althogh the power penalty is considerable azt close to 8 HP for the 200 A alone.
 
#9 ·
Well, I would give the lifelines a positive reccomendation. They are pros and have great customer service. They know their stuff and believe in their product(s).

As far as the alternator, I have to say that I agree that 200amps is pretty darned high. What if you are going to weather or into a strong current. If that thing is pulling 200, is your engine strong enough to still maintain the power you need? I don't know what you have, displacement of your boat, etc... (so telling us what your engine is will probably not do a lot of good, since there are many other varying factors). I would probably just drop a 100-120 in with a MS Charge controller, and plan on running it longer. If you have a generator, I would DEFINITELY not go with a 200 because the generator will be more efficient (fuel).

Instead, consider a wind gen and solar panels to help you balance out your load needs.

Just my thoughts.

- CD
 
#10 ·
Ruiz...understand your reasoning. I have over 1000AH of batteries on my boat and still would not put a 200AH alternator on my engine...despite Calder!! He is indeed a guru and I follow his advice myself on many things but the stress on the engine bearings is considerable. May I suggest you contact your engine manufacturer and ask them is attaching a 200AH alternator would have any effect on your warranty.
I understand now why your battery A/H atings are a bit higher than standard wet group 31's. One thing I guess you are considering is that with a larger wet cell bank you should probably be able to deliver the same bulk charge amps in a relatively short time as you could with the AGM's if you are close to 800AMP capacity with wet cells and a 200Amp alternator. Plus...you'll have extra usable capacity. Offsetting this is the additional maintenance you will face and the longer projected life. Tough decision...but cost differential should probably sway you to the flooded unless the space is really difficult to get at for maintenance.
 
#11 ·
My experience with a 450 Ah battery bank and 150 amp alternator.
The alternator would reach full output only at engine criuse speed. A lot of my charging was done at anchor. I never saw more than 90 amp going into the batteries and this only for less than 5 min. before it dropped off (this with a top of the line Ample Power regulator). As a result I changed the alternator to a 90 amp unit that reached full output at a fast idle. This has been a much better setup.
 
#12 ·
I installed 3 Group 31 AGMs for 315 amphours. I run a 70 amp Balmar Hi-Output alternator w/external regulator. Also, a Group 27 AGM for a start battery. On my setup, and particularly since I only have a 13 hp Yanmar, I have a cutout switch that allows me to freewheel the alternator, use external, or internal. I found the cutout switch to be well worth the effort. I had a terminal break on the external, so was able to switch to the internal regulator till fixed, and though the alternator has a 45 second delay on starting, in cold weather, it will bog the engine down enough to stop it. It also came in handy when I had to run against a very stong current.

I went with the West Marine AGMs for two reasons over the Lifelines. One, I got a heck of a discount through a friend (almost 50%). Second, if you have a problem with the Lifelines, it is handled direct, not through a dealer. So that, if you had to return one, it had to be sent to the factory (info from the local Lifeline dealer).

I also have a Air-X wind generator, and so far, have been very content with my whole battery setup. I'm using around 100 ah a day, and have gone for 2 days without using the engine and still had plenty of juice.
 
#16 · (Edited)
No Small Wonder!

QC1111,

"My experience with a 450 Ah battery bank and 150 amp alternator.
The alternator would reach full output only at engine criuse speed. A lot of my charging was done at anchor. I never saw more than 90 amp going into the batteries and this only for less than 5 min. before it dropped off (this with a top of the line Ample Power regulator). As a result I changed the alternator to a 90 amp unit that reached full output at a fast idle. This has been a much better setup."

And, no wonder this is better. 150A is much too much for a 450AH bank, assuming flooded batteries. Trojan recommends a charge of 10 to 13% of the 20-hour AH capacity or, when a "fast" 8-10 hours charge is needed, they say up to 20% of rated capacity. This would be the 90 amps. Maybe the Ample Power regulator knew that? Or, maybe, the drive pulley was too large to turn the alternator fast enough?

Anyway, glad to hear all is fine now. And, it's a good lesson in sizing a charging capacity.

BTW, I believe Nigel has a 200A alternator because he favors AGMs on his boat, and they can be bulk-charged at a much higher rate than flooded cells.

Bill

RE: the battery caps, there are two basic types. The older and more popular one is the HydroCap. You can Google it for sources...there are lots of them, including this one: http://store.solar-electric.com/hydrocaps.html

They do, indeed, work very well. Rolls/Surette even includes them on their high-end batteries. Wish I had the space for them, but my battery boxes are too low; otherwise, I'd buy them right away.

The HydroCaps require that you remove them when equalizing your batteries, I believe, or they can be damaged. There's another brand that's popular, too, and doesn't require removal; but it has different disadvantages.

B.
 
#18 ·
Ruiz-
The rule of thumb is that you can recharge wet cells at 1/5th of the stated max capacity, and AGM cells at 1/4 capacity. This is because of the different chemistry. Lifeline make some statements that indicate they may simply have a very robust case--and that could mean less space inside, lowering capacity. Or, they may simply use a different alloy for other reasons. Or both.<G>
If you run your battery bank down to 60% capacity (I think most would argue 50-70%, so I'm splitting that) then you are looking at putting 40% of the capacity back into the batteries during every charge. That means about two hours or run time, at maximum acceptance rate, with an alternator that "only" puts out 1/5th of the battery capacity. Anything more is wasted--unless you are running other loads (watermaker, reefer, etc.) at the same time.
So even with 700A of capacity, you only need a 140A alternator for maximum charging speed.

Once you reach 100A or thereabouts, you can no longer run an alternator from one simple v-belt, you need a ribbed belt or double belts, which are problematic unless you adjust them both very evenly. Something to consider, as is the option of using twin 80A or 100A alternators, plain belt, full redundancy, if there is room to install them on opposite sides of the engine.

Wet cells are still cheaper than AGM, but AGM will charge faster, and since they are sealed you *can't* top up the electrolyte if you overcharge them. But, they will keep working even if flooded or knocked over. There are tradeoffs.
 
#19 ·
Giu..here is one sourc but I don't know if they ship out of the USA.
http://store.solar-electric.com/hydrocaps.html

Here is the manufacturer information:
Hydrocap
975 NW 95th St
Miami, FL 33150
(305)696-2504

Ask for George and he will send you a form to fill out for correct fit to your batteries and installation. I couldn't find any e-mail or direct website.

Note...they make your battery taller so you must have additional room in your battery box to accomodate them. Also...you most remove them when doing an equalizing (hi voltage) charge routine if you do those occasionally for maintenance.
 
#20 ·
HelloS...I think your "rules of thumb" are way off on the AGM's. There is NO effective current limit to charging AGM's...only the same voltage limit as wet cells. Example:
Most flooded batteries should be charged at no more than the "C/8" rate for any sustained period. "C/8" is the battery capacity at the 20-hour rate divided by 8. For a 220 AH battery, this would equal 26 Amps. Gelled cells should be charged at no more than the C/20 rate, or 5% of their amp-hour capacity. The Concorde AGM batteries are a special case - the can be charged at up the the Cx4 rate, or 400% of the capacity for the bulk charge cycle. However, since very few battery cables can take that much current, we don't recommend you try this at home. To avoid cable overheating, you should stick to C/4 or less.In other words...I could put a 400Amp current into my AGM's to recharge them as long as I didn't put in too much voltage. Therefore you get a MUCH MUCH quicker "fill-up" from a high amp alternator than you do with a wet cell battery. The only concern I have about Ruiz's plan is the effect of the alternator on his engine...not the ability of the AGM batteries to take more current. The whole article is a great battery primer and well worth a read:
http://www.windsun.com/Batteries/Battery_FAQ.htm#AGM,%20or%20Absorbed%20Glass%20Mat%20Batteries
 
#21 ·
Crown batteries

I'm thinking of replacing my 2 4D house batteries with 4 6v Crowns that are made for industrial use, such as floor polishers The rep stated he was concerned that my 40 amp charger and 120 amp alternator with smart reg would fry them. He recommended only 20 amps of charge at any time. Any thoughts or feedback?
 
#24 ·
So the batteries are each 245Ah @ 6V, and you will be combining them to get
245Ah @ 12V from each pair?

If you run them as two separate batteries, each 245Ah @ 12V, each can take about a 49Ah maximum* charging rate.

If you run them as one big 490Ah battery, 98Ah is the max charging rate.

So your 40Ah charger is way safe, either way, and your 140Ah alternator is more than you need, either way. As long as your regulator is working properly, the fact that there is extra power available should NOT be a problem, it just means your alternator will run cooler and last longer. But, you want to make sure the regulator is working properly.

And for best battery life, you ideally want a 3-stage marine regulator which also has a temperature sensor that installs on the battery post. (3 or 4 stage, either one, with a provision for equalizing the cells once a month or so.)

[*maximum, meaning 20% capacity, a rule of thumb not an absolute figure.]
 
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