electrical upgrade

[lowufo]

looking for opinions and recomendations on house batteries .I want to install the longest lasting , most durable ,most cost affective there is.how many should I have ? is more better ? I plane for solar and wind generation in the future .but for now, engine alt. and occasional shore pwr ( 99.9% on a hook ) and honda 2000 watt gen.when needed .....golf carts ? marine deep cycle ? starting from scratch, will be installing an all new electrical system in our B32
thanks

[Sailmachine]

I guess it all depends what you have in your boat. I am designing my system for 6v golf cart batteries. two for the engine and 4 for the house. This might ever be over kill so i will most likely start with two for the engine and two for the house but with room to expand to 4 batteries for the house. I don't see why a similar setup would not work for you. If you spend all your time on the hook or plugged into shore power your batteries should be about the same. You should be adjusting the consumption rather then the battery size. If you were plugged in all the time go ahead and add a TV, computer, dvd, lots of lights, microwave and electric razor. Who cares you're plugged in and don't need any battery. If you're on the hook, get oil lamps, led bulbs, a book and disposable razors. now your using such little power you can stay on the hook forever end never worry. Larger battery banks make life harder not eraser. you will have a hard time keeping them charged with solar and wind alone. You will need a bigger alternator, generator, and more expensive charger. All this just so you can nuke a tv dinner and watch a movie. Give me a grill, and a book or some good friends any day over electronics and no power needed. Sorry for the rant. Its just me.

Pete

[Rachel]

That's a question that could have a very large number of answers, so it's hard to pick just one.

As Pete alluded to, I would work "backwards" if it were me.

1) For starters, how do you use your boat? You did say mostly on the hook, but do you have to have your electric coffee maker? Happy with oil lamps? LEDs? Do you need running lights to stay on all night? Run an autopilot? Laptop? Refrigeration? Electric Windlass? Etc.

2) Next I would make up a consumption list, by taking the draw of the items I have (or want) that use electricity x how many hours per day they would see use on average. Then you know how many amp/hours you "take" per day. It's best if you can keep from drawing down your batteries past 50% - gives them longer life.

3) Another factor is how much room you have for batteries. For example, golf cart batteries are tall as compared to others and need to be used in pairs (I like them so this is not a knock). Can you fit two batteries? Four? Ten? That may or may not be something you want to alter.

4) Tied in with how many amp/hours you use, and the size of your battery bank, is how quickly and reliably you can recharge the batteries. Obviously the quicker/more reliably you can do this, the less battery capacity you need.

5) How about "fuels" and how you will carry and stow them? Gasoline for a generator is a fuel that must be stored safely. Solar panels need room for mounting out of shade. Larger alternators need to be mounted and the engine needs to have the oomph to run them. Wind generators need to be mounted and their location and sound accounted for.

6) What about budget?

I'm no expert, so I couldn't actually design a system, but I also don't think anyone could just "tell you what is best" without having more answers to the questions above. The machine needs data to churn! :D

Rachel

[mitiempo]

I agree with Rachel - work backwards from expected use. But here are recommendations.

Golf cart batteries (flooded lead acid) are probably the most cost effective way to go. If you have room for 4 use them as the house bank - giving you about 450 AH in series/parallel. This gives you 225 AH of use to 50%. As long as your use is less than 100 AH/per day or so you will have 2 days use before charging is needed. If you are miserly about use this may give you 3 days + before charging is necessary.

For starting golf carts are a waste. Best would be a single 12 volt start battery, also flooded. The best way to charge is to send all sources (solar, alternator, wind gen, and Honda) to the house bank. Charge the start battery with an Echocharge or ACR. Starting is only a draw of an AH or so anyway. If you wish you can use the start battery as an emergency battery and use the house bank for everything. Saves switching banks and couldn't be easier.

[Maine Sail]

.I want to install the longest lasting , most durable ,most cost affective there is.how many should I have ?

Longest Lasting:

Gells = Most Expensive: Theoretically gell batteries can last for a very long while BUT they must be charged correctly and they like to be at or near 100% SOC (state of charge) often to get the most life. Rarely do they ever get taken care of and charged in such a manner that they actually outlast a bank of 6V wets. They accept more charge current than wets which can be a benefit and they do not "gas".

AGM = Very Expensive: Absorbed glass matt batteries are CLAIMED to last for a long while, BUT, like gels, they need to be charged correctly and they like to be at or near 100% SOC (state of charge) often to get the most life. On average the reports on many of the cruising forums say that AGM's rarely outlast a bank of 6V wets or even 12V wets for that matter. They accept more charge current than both gells and wets than wets which can be a benefit, and they do not "gas".

With AGM's I often see folks buy them for what I see as the wrong reasons.

Wrong reason's that I have seen:

#1 Bought a 200-800 ah bank for their high acceptance rates then fed them with a 100 amp alt and 40 amp shore charger which did nothing to actually take advantage of the high acceptance rates.

#2 Bought them for the "low maintenance" then ran the engine 35 hours a season. Even the worst wet cell on the worst charger won't boil off on 35 engine hours per year unless there is a serious charger problem.

#3 Bought them for low self discharge rates, which they DO have, but then left them sitting at 50% - 80% charged after each sail and killed them in three seasons.

#4 Bought them for the claimed "longer life" then found out they were dead in 4 seasons anyway, when the previous wet cells lasted 7.

#5 Bought them to replace wet cells that died a premature death then the AGM's proceeded to do the same because the owner refused to address his/her battery practices.

6# Bought them because they don't give of "gas fumes" when charging. In this case the owners previous bank had zero signs of corrosion and in four years had never even taken water due to such limited use. When I opened them up they were still full and load tested at nearly new. Gave that bank to a friend who got two more seasons out of them. The "new" gas-less AGM's died at year five.....

#7 "The guy at West Marine said they were the best." He then proceeded to fry two stock alternators and finally had to buy a fully gourmet charging system for another 1.3k. Previous wet bank on a dumb regulated alt lasted six years and the bank cost $300.00 vs. $1000.00 + $1300.00 alternator regulator installation. $2300.00 vs. $300.00. I'll be surprised if he gets 6 years out of the Deka/WM AGM's (only on year two now)...

I see and work on boats left on moorings, it's Maine, and the only thing I can ascertain is that AGM's do not like to sit discharged as on-mooring boats often do. I have seen LOTS of expensive AGM banks die before 5 seasons. I also check date codes every time I am at my local battery distributor on the core pallets. The 6 year old AGM core is a rather rare up here while the 6 & 7 year old wets are not all that uncommon on the pallet. Most of the dead AGM date codes are between 4 & 5 years at my friends shop.

Nearly every boater I know with AGM's has bought them for their ability to take a fast charge then fed them with a diminutive alt that took no advantage of the high acceptance, wrong reason #1. I have personally seen a 100 Ah Lifeline take 85 amps for more than just a few minutes. I have yet to see any boater truly take advantage of the actual acceptance rates on a large bank because you'd need a HUGE alt to do so and small sailboat AUX engines just can't do this. On top of that you really need at the least and alternator temperature sensor so you don't fry your alt. This will require external regulation which is another added expense.

I replaced four T105's on a Sabre that had lasted 7 years with a 90 amp dumb regulated alternator. Boat resided on a mooring with no solar or wind. The Lifeline bank cost over $1400.00 and was flat dead going into the spring of what was to be their fifth season. At the same time we upgraded the batts we did a full gourmet charging system with 150 amp alt, dual pulleys, MC-612 Balmar regulator, temp sensing etc. etc. on and on. He even bought a maintenance charger that was recommended by Lifeline tech support for the off season where they were stored in his 55 degree basement and cycled on and off the charger to keep them at 100% SOC. Total cumulative motor run time over the four previous seasons was just over 400 hours. The bank had never been discharged below 60% SOC during these four seasons as monitored by Link 20. Dead, grave yard dead. Lifelines attitude, not out of the ordinary, try equalizing. He's back to 6V wet cells again, an expensive experiment. This is one I really feel terrible about because at the time I had bought the AGM static hook line and sinker and really pushed this guy towards this set up. I have wracked my brain as to what cased this but there is no answer. Everything was done by the book.

Oh and then their is my buddy who is the head systems tech at a very well respected boat yard here in Maine. He is an ABYC marine electrician, NEMA certified etc. etc. on and on and on. Probably one of the best marine guys I know in terms of knowledge. His own bank of AGM's in his own boat lasted three seasons (Deka's). He's gone to gel.

Don't get me wrong, there ARE benefits to them, and if you can truly take advantage of these benefits they can definitely be worth it. Most I see don't truly take advantage of the benefits, but some do. If you go AGM try and keep them fully charged as best you can. If on a mooring get solar or wind to augment. If you can afford a $1300.00 bank you should really take care of them. In my opinion and based on the "claims" these banks should have all easily gone 7+ years.

I find this statement from Trojan very interesting compared to what was originally marketed about AGM's.

Generally, gel and AGM batteries have about 20% less capacity, cost about two times more, and have a shorter cycle life than comparable flooded lead acid batteries. However, Gel and AGM batteries do not need watering, are safer (no acid spilling out), can be placed in a variety of positions, have a slower self-discharge characteristic, and are more efficient in charging and discharging than flooded batteries (see table below). Gel batteries are more suitable for deep cycling applications whereas AGM batteries are more for light cycling and engine-starting applications.

Wet Cells = Best Bang For The Buck:

The 6V wet cell battery is a tried and true work horse. The entire golf car industry and industrial machine industry relies heavily on 6V batteries often of the GC2 size, which is very common amongst cruisers, because nearly everywhere on the planet these robust batteries are widely available. The reason many cruisers use 6V batteries is for increased cycle life, $$ per discharge, and $$ per Ah of capacity. The plates are thicker, taller and more robustly built than a 12V deep cycle of the same capacity. The 6V battery will have only 3 cells where the 12 will need 6 cells thus thinner plates in the 12V battery. 6V wet cells win on price, Ah per dollar, and value every time. They do lack high acceptance rates, which with many charging systems on sailboats is a non-issue because they can't actually benefit from this due to HP and belt restrictions, the lack ability to lay them on their sides, and they do require maintenance and can "gas". A bank of four 6V batts at 450 Ah's can accept charge current of about 20-25% of the 20 hour Ah rating. a 450 Ah wet bank can take the full output of a 100 AMP alt when deeply discharged but this won't last for very long as they charge begins to taper due to acceptance once at or near 80% of capacity or so. If you want to go bigger than 100 amp you will spend a lot of money on custom pulleys and brackets to fit a larger alt. In contrast that same bank in AGM could theoretically take over 300 amps IF you had a way to feed it that which most don't.

Testing has been done between 6V and 12V longevity but it does not take a scientist to see why a typical 12V battery with plates that are roughly .040-.060 thick can't compete longevity & cycle life wise with the typical 6V battery that has plates in the .105 -.110 thick range.

Here are typical plate thicknesses from four of the leading US 6V battery makers:

US Battery US2200 - 232 Ah, +Plate Thickness .110

Crown CR225 - 225 Ah, +Plate Thickness .105

Superior GC1200 - 220 Ah, +Plate .115

Trojan T105 - .110 (Trojan will not disclose this data but US Battery has done destructive testing on the Trojan's and confirmed the plate thickness)

My current favorite battery from the list above is the US Battery US2200 if you have a distributor near by, we don't have one in Maine so going to MA to get them is a pain.. They compete directly with Trojan and the US2200 is their T105 killer and costs significantly less.

is more better ?

Before asking, "is more is better?" you should ideally know what the baseline of consumption is before you can know what "more" needs to be. I would always suggest a battery monitor so you know accurately what your system is using in terms of consumption and what your charging sources are actually returning to the bank over how long a duration.

The Victron BMV-601 from Jamestown distributors is only $175.10 and a very good value. Buying this first can actually pay for other upgrades because you may find your calculations were way off and that 450 Ah bank you thought you needed really only needed to be a 225 Ah bank, thus paying for the battery monitor. Every boater I have installed a battery monitor for raves about them and can't believe they did not do it sooner.

In short, more is better. The bigger the bank the shallower the discharges will be. Deep discharges kill banks faster. If you have a bank you regularly cycle to 50% SOC vs. one you cycle to only 75% SOC then the bigger bank only dropping to 75% SOC will outlast the one regularly being discharged to 50%. 50% is the lowest you generally want to discharge to.

I plane for solar and wind generation in the future .but for now, engine alt. and occasional shore pwr ( 99.9% on a hook ) and honda 2000 watt gen.when needed .....golf carts ? marine deep cycle ? starting from scratch, will be installing an all new electrical system in our B32
thanks

In my opinion 6V wet cells would be your best bang for the buck, should last a good long time if properly cared for, and you don't need a fancy regulator to run them. Also, remember that when charging off an alternator you will rarely charge the bank back beyond 80%-85% of capacity due to time constraints and basic battery acceptance curves. This means a 450 Ah bank quickly becomes a bank with only 135 usable Ah's before you hit 50% bank capacity if only getting back to 80%. 80% of 450 Ah's means you charged back to 360 Ah's of capacity. 360 Ah's minus 225 Ah's (50% capacity) = 135 Ah's that are usable while away from the dock and only using the alt to re-charge.

Good luck!!

[lowufo]

Thanks for all the input ! I think I'll be useing the 6v US batteries. But........ I have a westerbeek W21 with only a 50 amp alternator. If I am correct in my understanding ,I will need to upgrade the alt. to 90-100 amp unit, is this correct ?. I want to keep the system as simple as possible. is a bolt on alt . an option or do I need to get more involved . I'm think 450 AH should be enough for our needs
thanks !

[Maine Sail]

You MAY find that 225 Ah's is enough. As i mentioned do an accurate energy budget or get a battery monitor. A 50 amp alt may be fine so long as you are not totally depleting your bank.

Our own boat had a stock 50A alt running on her for 2982 engine hours and
many, many thousands of hours of solar charging, 5 1/2 years of solar charging, to be exact, and an additional 4 seasons since we've owned her.

The boat did a five year 24/7, 90% on the hook, world cruise under the ownership of my good friends Norm & Judy before we bought her and used the stock alt on a 250 Ah bank.

For the average coastal cruiser who does 100 engine hours per year or less 2982 hours is nearly 30 years worth of engine/alternator charging time. 30 years! In that time the batteries survived quite well considering the 24/7 live aboard, on the hook, nature of use.

The first start battery & house bank was retired at the beginning of year seven after 5 1/2 years 24/7 use and nearly 2700 hours of engine run time, or 27 coastal cruising years of "dumb" 14.4 volt alternator charging. It was only retired because a new bank was purchased. The start battery was charged via an VSR/Yandina combiner during that time.

The old bank was still performing when retired it. The only reason for
replacement was a re-configuration to a slightly different bank and I did not want to mix ages.

I still use two of those batteries to this day in my barn for running a 12V
stereo for music when working as well as a 12V transfer pump I use for servicing my spa. It drains the entire contents of my 9 person hot tub via a Rule bilge pump with no complaints after "27 years worth" of dumb charging a 250 Ah bank with a 50A alt. It has been charging a 375 Ah bank now for the last 4 years. While I would never use this old house battery on a boat it is not totally "dead" and still, surprisingly, actually performs duties.

The start battery is still going too and is currently on my brothers Mako. It is
now 10 years old. It starts a 225 HP two stroke outboard, not a big load, though is admittedly finally starting to get weak and will get replaced this winter. At 10 years old after the equivalent of 27 coastal cruising years of dumb charging via an ACR/combiner and it is still actually working. This was also a very inexpensive start battery to begin with, Wal*Mart, but even after 2700 hours of alternator charge time, thousands of hours of solar charging, all with an automatic combing relay, the battery still works and starts a 225 HP outboard at year ten. Of course, it did take three years off before we threw it in the Mako this summer after an unfortunate incident that killed my brothers existing bank (read partial sinking thanks to PVC seacocks used by Mako DUMB!!).

My long winded point is that you have nothing to lose by trying the stock alt. I am STILL using that stock alt even though I have many 90 & 100+ amp alts sitting in the barn along with regulators, I just don't need them.

While there is the potential for overworking that alt, and burning it up, if you are not depleting below 50% you may be just fine. "Dumb" regulators, like smart, are really nothing more than voltage limiters. Until the bank gets to what ever the voltage set point is, say 14.2V, the alt will put out what ever the bank will "accept". Batteries decide what the amps supplied are, not the alternator. Once the voltage reaches the alternator set point voltage it is more drastically limited by the batteries acceptance rates which will continue to decline until they are taking very little in terms of amps. The regulator and alt do not put out "amps", unless they have somewhere to go, they try to raise the voltage and the batteries "accept" amps based on internal resistance of the battery which varies with the state of charge.

I'd say to try the 50A and spend the saved money on a battery monitor. The best investment you can make is is reduced consumption, LED's and energy conservation go a long way.

[lowufo]

Excellent !! I'll take your advise.1st calculate power consumption, , what would you suggest for a solar set up ? I am starting from basicly new when it comes to the 12v wiring on the boat, and i would like to run a laptop for a few hrs a day at times,(hate to miss all the cool stuff here online ) inverters ??
Thanks Again !

[sail_fix]

One of the nicest things about forums like this is that we share non-judgemental information about what we have seen work or... sometimes not.
On our 34 footer I have tried to stick to a relatively simple system. I often wish for more gadgets and add-ons, but that's often just because I like gadgets. :)

We have a 23 hp diesel with the stock Moto 50 amp alternator. Right after acquiring the boat in '94 I changed from the stock pair of group 24's to a house bank of two Trojan T-145's, and an added emergency AGM spiral-cell battery because it had to fit back under the aft cabin berth where there is no way to monitor liquid level in a flooded battery.
The charging curves are extremely similar, so I keep both banks on a multi-stage solid state charger at the dock, and underway almost never charge the "spare" battery. We start the diesel once a year with the AGM just to check its condition.

This is not really proper according to many experts, but it seems to work ok for us. I get about 5 to 7 years out a bank.

We have Frigoboat 12 volt refrigeration that runs pretty much year around at the dock easily two or three days at anchor.

Someone mentioned a laptop -- I admit that when I run my old iBook for charting at the nav table, I can see a 4 amp jump in usage. I suppose that there is a lot of conversion loss going thru the little inverter and then to the computer's plug-in charger.

Fair Winds.

[Duncan]

Someone mentioned a laptop -- I admit that when I run my old iBook for charting at the nav table, I can see a 4 amp jump in usage. I suppose that there is a lot of conversion loss going thru the little inverter and then to the computer's plug-in charger.

Yes, lots of conversion loss up to 110, then back down to 12 again. I have a 12V DC-DC adapter for my laptop.

[timsterspuffin]

Hi loufo!

The electrical conversion ideas I've been researching the last several months have been impressive and offer answera to most/all of your questions. The factors that will make your choice(s) will be primarily a linear function of your wallet!

The Aussies, Kiwi's and Euro-folks have worked these systems out and offer a variety of "packages". The pods, saildrives and inboards fitment will drive your selection. You can always use these as a "kicker" on most any boat you can mount anything else.

The "hybrid" concept is a great one- my US-27 will end up with some rendition of the DES/GES systems widely available. By no means the solution for anyone with a small boat.

If you/others are patient- I will be happy to share my research........my project is 2 years from the drink and electric drive technology is flipping over faster than I imagined. Our group surely has some others also bitten by the electric bug and considering these conversions.Since I am an inland/freshwater sailor, my conversion is aimed at reducing the stinky,noisy, oily "floaties" we have polluting our slips and launch ramps.

Most (electric) companies' motor engineers are keen on calculating your specific needs and offer data for your boat.

My US-27 is a 6,250 lb masthead sloop which gives me lots of space and options for batteries, generators and some PV arrays.
One U.S. company suggested a 20-30 KW motor, another claims 10 KW is plenty. 10 KW equals apx 7.5 HP in gas a little more in torque in diesel and beats either petro-fueled option in that power BEGINS at 0 RPM! When you look at power curves comparing all these you soon realize why electrics are so superior in that sense.My guess is you'll find something that works pretty good off of 24-48 VDC.

If others are curious- please post your thoughts. My winter is full of such research.(Meanwhile,many questions are clearly answered and detailed by various companies as part of their retrofits.

Keep it keelside down!

[Ric in Richmond]

Great discussion and so timely for me. I have a set of 5 season old batteries that just don't hold much of a charge now.

I run a start battery and 4 6 volt Group 24s. Charged off a stock universal alternator and a combiner.

Two port.two starboard through a 1/all/2 switch so I can "set aside" some power if the kids are rocking the stereo or won't turn of lights.

Anyone find a set of group 24's they like for house batteries? Right now I have a 4 interstate 6 volts that, while advertised as deep cycle, apparently aren't really.

[Maine Sail]

Great discussion and so timely for me. I have a set of 5 season old batteries that just don't hold much of a charge now.

I run a start battery and 4 6 volt Group 24s. Charged off a stock universal alternator and a combiner.

Group 24 is a 12V size designation. Are you sure they are 6V? If they are 6V they are most likely the GC2 (golf cart 2) size which is similar in dimension to a group 24 but taller.

Two port.two starboard through a 1/all/2 switch so I can "set aside" some power if the kids are rocking the stereo or won't turn of lights.

You are significantly better off to run one large bank rather than two smaller ones. Separating the two banks of 6V batts only serves to more deeply discharge each bank and thus shorten it's life. The shallower the discharge the longer the life. The bigger the bank the less discharge at the same Ah;s drawn down.

Taking 150 Ah's out of a 225 Ah bank, two 6V batts, puts you at a 33% state of charge on that bank. If you left the two banks together and then drew 150Ah's off it. 450 Ah's - 150 Ah's = 67% SOC. Your batteries will last significantly longer when only drawn down to 67% SOC vs. 33% SOC. You are using the SAME Ah's in each situation but the batteries will last a LOT longer the less you draw them down. If you don't have a reserve battery then a group 24 12V would be great and you could permanently combine the 4 6V batts for one 450 Ah bank and add a group 24 starter batt.

Anyone find a set of group 24's they like for house batteries? Right now I have a 4 interstate 6 volts that, while advertised as deep cycle, apparently aren't really.

Again 6V batteries will be a GC2 size generally speaking and group 24, 27 and 29/31 are 12V sizes. You need to determine if you have 4 12V group 24's or 4 6V golf cart batteries. Any 6V battery will be a deep cycle battery as that is their intended and designed use. Two group 24 batteries, even deep cycles, will never last as long as a 6V used in the same manner.

Five years is not bad if you are treating them as you are. You could likely get seven - ten years out of that same bank by adding a battery monitor and practicing good battery management. Without knowing what your state of charge is, how often you are back to 100% etc. etc. it is very tough to blame the battery for not being "deep enough" cycle... I have seen folks kill t-105's in a year from poor battery management and others get 10+ years out of a set from good bank management. Knew one guy who though deep cycle meant you could draw them to dead each use "deep cycle". He would kill them then start on the reserve battery, and did it every weekend. He replaced banks almost every year and always complained about how much "marine" batteries sucked.....? Couldn't tell him otherwise though, yet he was a good customer for the battery supplier, I bet they wish they had more of him.

[Ric in Richmond]

Appreciate the reply.

They are 6v. They fit a group 24 box with little room to spare. I will get the model number ASAP.

It used to be 2 banks of 2 x 12v in parallel and a 1/all/2 switch that you could switch in the start battery.

I pulled them and rewired to 6 volts in series to make 12v then in parallel across the 1/all/2 switch. Ran a separate circuit for the start battery and charge off a combiner. usually leave the house bank on all and that is a good point on running them all on all the time.

I usually do that, but will sometimes reserve a bank. I may need to rethink that.

[timsterspuffin]

The exchange here regarding batteries, types and pros and cons are good food for thought- I'm impressed with the amount of knowledge out there.
My sincere apologies for throwing a few bucks worth of thought into the topic!!
BTW,The folks at MIT and research universities are bustin' their picks mining out better battery stuff.
The considerations for electric power storage technology is driven with a lot of new batteries coming out of R & D, showing impressive output -, AH and longevity. As someone estated earlier-- batteries are only as good as their maintenance and the mindful monitoring by their owners.That person also correctly stated: most batteries that experience deeper discharge (past 50% as average) are doomed to shorter, less predictable lives and output. The FLA (flooded lead-acid) manufacturers are neck-to-neck as their premium plate materials are good for 5-8 years typically- if discharged to no more than 50%. No matter who makes them- you can only package and provide the best recipe for electrolytes and lead alloys.
Who can afford the NMH or Lithium-ions at this point in time? These are not allowed for sale to Joe Public as they have hazmat reuse registration tied to them.
Back to the point: your car battery lasts 5-8 or more years because it stays well above 50% discharge most of its life.
Temperature has alot to do with CCA with FLA's- they lose amperage severely below freezing and more below zero- I doubt many will be in a boat at these temps.Note "marine" batteries have ratings at 32 degreesF.

My experience in industrial batteries and charge systems (telephone company) is a vastly different duck! Bell labs engineers (circa late 70's) invented FLA vertical-stacked cell batteries that nominally produced 2.25 volts with a design life of 40 years! Needless to say,also out of reach for most.These are large, stationary monsters, monitored with "pilot cells" in each string of 24. Strings of batteries are only as good as their weakest link (cell(s); same is true for any multiple arrangement of what is a bunch of cells tied in series or paralell.
All of this vulnerability has been applied to "strings" where series batteries are now gang-charged to optimize their life and assure max output.These "monitoring" charge systems are the best answer to date- and should be available for 6 or 12 volt batteries, whatever type they are. They aren't cheap but save you some costs of identifies the failing batteries and bank issues before they take down the whole string.

I apologize for runnung off on this palaver.............I'm waiting for cheaper Lithiums and other technologies like "molten metal".

Timster

[lowufo]

cool stuff boys !!

[brob76]

Ric,

Where do you house the battery bank on your A35? I'm getting ready to buy a new bank of 4 Trojan T105s and was considering building a box in the bilge just aft of the water tank. Right now they are in the stbd cockpit locker but I'd like to get all that weight as low as possible.

[Ric in Richmond]

The batteries on my A35 are behind false drawer fronts at the front of each settee port and starboard. The weight is low and centralized. There are lift off hatches above them for service and access. They aren't gas tight so that might concern some.

I have the model with the galley that runs across the hull at the companionway.

The batteries in there now are interstate u2xhd which I really think are a mixed use (ie heavy duty starting battery) and not suitable for a deep cycle in any way. They are 10.5 x 7 x 9.5 . LxWxH

I need to find a decent deep cycle to fit that space or modify the boxes. Current boxes are works of art. 3/4 marine ply all screwed and glassed together and look like art....really want to try to NOT have to rip those out.

[Duncan]

They aren't gas tight so that might concern some.

I wonder about this, since I would like to centralize the location of my batteries as well. This is mostly to improve the trim of the boat, since the batteries currently sit on a shelf high in a cockpit locker (i.e. too high and too far aft).

Here is the state of my knowledge/assumptions/questions before actually checking any of it yet.

1) It is hydrogen gas, which is lighter than air, so that we don't have the same type of explosion risk as with propane or other heavy gasses?
2) If the battery box is adequately vented, that will keep the box itself from becoming a bomb of trapped gas?
3) I have the impression that the batteries only outgas when they are charged hard, and that "normal" charging does not result in the production of hydrogen gas?.
4) Even when batteries do outgas, the amount of hydrogen gas released is small and fairly easily diluted in the atmosphere?

Based on the above (all of which needs checking), I get the impression that putting lead-acid batteries in the cabin is ok so long as the battery box is vented. I wonder if it is worth it to improve this venting by providing a line to, say, the side of the cabin trunk, and/or providing a small fan outside the box to force along more venting?

Edit: Here's what looks like a pretty good paper that addresses a number of the issues on gassing/ventilation - http://www.battcon.com/PapersFinal2008/ ... ROOF_6.pdf
I don't understand it yet, but the general impression I get is that if you can ventilate to keep hydrogen concentrations below 2%, that meets applicable (IEEE) safety standards.

[Hirilondë]

They aren't gas tight so that might concern some.

I don't think I have ever seen a gas tight battery box.

Current boxes are works of art. 3/4 marine ply all screwed and glassed together and look like art....really want to try to NOT have to rip those out.

I don't blame you. Well constructed/installed battery boxes take significant time to build/install. I have made them out of FRP as well as epoxy saturated plywood with glass reinforced joints. I think the primary purposes of a good battery box are:

1. contain the battery in place under all conditions including a knock down and roll over
2. contain the boil over under normal conditions
3. protect the batteries from contact by other objects, especially conductive ones
4. if in the bilge: protect the battery from bilge water, at least until it rises to cover them

[Tim]

Batteries are routinely found in and beneath accommodation spaces. There are no standards to suggest this is not completely acceptable.

The boxes should not be gas tight; in fact, they're supposed to be vented in order to cleanly and safely release the minimal gasses produced under some conditions. As summarized in the previous post, the box itself need only contain the battery to certain specifics (see below) and is also supposed to contain spilled electrolyte.

ABYC E-10.7 (PDF File 17.0 kb)

[Hulukupu]

It may be implicit in some of the discussion above, but inexpensive plastic battery boxes serve the purpose of secondary containment within a self-made FRP or plywood battery box. The plastic boxes provide redundancy in holding leaking juices, keeping your outer box clean and, sometimes, convenient handles to pull your batteries out with. Of course, if they are tight-fitting, they can be a pain to get the battery out of unless you have had the foresight to install a strap on the battery itself.

[Duncan]

I got a chance to study the reference paper I posted the link for a bit more carefully, and I have summarized what I learned below.

I also wrote one of the authors to ask him if he might be able to answer this question:

Typical practices aboard sailboats are to mount the batteries away from accomodation areas (the cabin), in a box that will contain spills, and to ventilate the box. The first practice, however, conflicts with the desire to improve sailing characteristics by centralizing weight fore-and aft and side-to-side in the boat, while concentrating it as low as reasonably possible.
So, my question is: how much ventilation would be required to safely mount, say, a 450 Ah battery bank, on top of the keel of a sailboat (i.e. under the middle of the cabin accomodation space). Just to be arbitrary, would a pair of 1 square foot grilles at each end of the battery installation be likely to be sufficient?
I realize that this request presumes on your time and energy, and good nature, so I would understand completely if it's not possible for you to answer. On the other hand, I'd be happy to buy you a beer sometime, take you for a sail, or preferably both, should the opportunity ever arise

So, I promise I will post an answer, if I get one..

With respect to the questions I posted this morning:

1) It is hydrogen gas, which is lighter than air, so that we don't have the same type of explosion risk as with propane or other heavy gasses?

It is hydrogen and oxygen, at a ratio of 2:1. This mix can burn at atmospheric concentrations of 4%, so applicable standards for ventilation (IEEE, DIN) are aimed at keeping the level below 2%, or preferably 1%.

2) If the battery box is adequately vented, that will keep the box itself from becoming a bomb of trapped gas?

Yes, but "adequately" means below 1% concentrations, and these can be higher close to the battery.

3) I have the impression that the batteries only outgas when they are charged hard, and that "normal" charging does not result in the production of hydrogen gas?.]

Not completely true, they outgas constantly, but the rate increases exponentially under hard charging in warm conditions.

4) Even when batteries do outgas, the amount of hydrogen gas released is small and fairly easily diluted in the atmosphere?

Still trying to puzzle this out. There is a formula quoted which seems to indicate less than 1/2 litre of gas produced per Ah charging, so recharging a 450 Ah bank from 50% discharge could theoretically produce 225 * 0.45 = 101.25 litres of oxy/hydro gas. Diluting this to 1% obviously requires 10125 litres of ventilation (or about 350 cu.ft.), all divided by the time for this charge to be accomplished. I'll guess 6 hours, so about 60 cu/ft/hr.

So, 1 cu.ft./min., doesn't seem unusual in a sailboat, if there is a 1 sq.ft. grille at each end?

Anyway, apologies for being geeky. but I would like to put my batteries under the settees, without worrying that I had done something dumb. What d'ya think?

[Skipper599]

I myself have built a pair of open top, f/g covered ply holding boxes (one on each side under cockpit seating). In addition, I also have plastic, full covered, primary containment battery boxes, having lifting handles incorporated as well as Hold-down straps. I expect the batteries to have built-in lifting handles when I purchase them too.

[Hirilondë]

Just to complicate things I will present another issue in setting up a new batter system. If you expect to charge all of your batteries from the same source, usually the engine alternator for most of us, then proximity to each other is a concern regarding the batteries. Should the wire leads from the charging source to each battery be significantly different in length, or any battery significantly far down stream from another, then you will never really be able to keep them all equally charged. This means that one or more (depending on how many you have and locations) will likely never be at full charge. It also means that this (or these) battery(s) will most likely not last as long as they will have a poor charge/discharge cycle. In a perfect situation all batteries will be:

1. low and centered in the boat
2. near each other
3. near the charging source
4. well secured and contained

as well as meet all of the ABYC parameters.

Like everything in a boat, there is no perfect, parameters must be sorted out and compromises made, and the ever famous "damned because it's all related" applies.

[Duncan]

... the reference paper I posted the link for ...I also wrote one of the authors....I promise I will post an answer, if I get one..

I think we may get an answer here. I heard back from him, and he was reminiscing about drinking Mount Gay from dirty coffee cups aboard Ted Turner's boat in the SORC.

Small world! He promised to give it some thought, and I promised we could ventiiate a bottle of Mount Gay sometime ;)

[Capn_Tom]

I've been following this discussion as I am about to purchase all new batteries. My plan has always beens 4 Trojan t-105s for the house bank. I have been struggling with placement primarily because I prefer to keep them all together. I've started considering the Trojan L16H or the US Battery equivalent as an alternative. They basically provide the same AH in 1/2 the footprint but 50% more height. Availability is trickier and the cost would be slightly higher. Does anyone have experience with this model or additional points I should consider?

[Ric in Richmond]

Resurrecting an old thread.

Anyone have any experience with these?

http://www.batteriesplus.com/product/33 ... up-24.aspx

150 min @ 23 amps

75 ah.

Batteries Plus says the are DEKA rebranded to their house brand.

For 80 each I am not sure you can go wrong as long as they aren't total junk.

[mitiempo]

Are you planning on using it as a start battery? Or a house battery?

It is not a true deep cycle. And a pretty small battery. Good for starting though.

True deep cycle batteries seldom if ever give CCA specs.

[Ric in Richmond]

House battery. Will be 4 in parallel.

So I need a deep cycle in a group 24 box. Any ideas? This is kind of why I went off to the 6 volts that fit in the GR24 box. Those were disappointing.

The numbers I listed are taken off the actual battery. It says deep cycle and they also sell combination and starting batteries.....but is also lists CCA which is disappointing.

Same specs as the westmarine deep cycle group 24. And they mention CCA as well.....

http://www.westmarine.com/webapp/wcs/st ... 2011Annual

Not ripping out the 4 boxes so got to work with what I have!

[Maine Sail]

House battery. Will be 4 in parallel.

So I need a deep cycle in a group 24 box. Any ideas? This is kind of why I went off to the 6 volts that fit in the GR24 box. Those were disappointing.

Ric,

If you thought four 6V batteries were disappointing then you'll likely be very disappointed with four group 24 12V batts.

Deka re-brands that battery to many folks including NAPA. If you buy from NAPA get the one that is labeled Deep Cycle, it has a teal label, and you'll get the identical battery that WM sells for about half the price. NAPA does not list the Ah but it is the identical battery to the WM/Deka deep cycle spec wise. Do NOT buy the "starting/deep cycle"...

I would still suggest 6V batts over four group 24's...

What was disappointing about the 6V batts..?

[Ric in Richmond]

The 6 volts seemed to never hold a decent charge.

Autohelm / gps would pull them down as well as radio (FM/ ipod) by day and then anchor out and next day they would be way down.

Just didn't seem to do what I thought they should.

See the early post that details the 6 volts I had been using.

thanks!!!!!

[mitiempo]

I agree, the group 24's don't hold a candle to 6 volts in series/parallel. I have installed 6 volt batteries, Trojan and off branded ones, in many boats - in groups of 2, 4, 6, and even 8 batteries without any charge issues. There is not a better bang for the buck.

Do you have a battery monitor? That is the key to knowing the state of charge of any battery bank. Without it you will not really know what is happening to your batteries.

The Victron BMV-600 is $158 at Jamestown. Highly recommended.

[Ric in Richmond]

No monitor. I should add one!

T105's won't fit the Z axis of my box.

[mitiempo]

I would pick the batteries best suited and modify the box or build a new one to fit. Or look at other locations where they may fit with short wire runs ideally.

My boat came with 2 group 24 batteries, one of which died and the other is close to death. I am not replacing them until I head off cruising as they aren't needed at the dock.

I plan on a bank of four 6 volt (Trojan T-105 or similar) in series/parallel and will have to build a box for 2 on each side of the engine, low and as far inboard as possible in the cockpit lockers. There will be a start battery elsewhere.

I already have the battery monitor.

[captphil416]

The information passed on here has been outstanding. Another point for anyone going offshore, Gel and AGM batteries can be prohibitively expensive. Fisheries Supply up in Seattle sells an outstanding Polyethelene battery box for 2 GC batts. at a very good price. My last set of GC batts went 8 years and were replaced only because I was headed offshore. Amongst sailors here in Solomons there is also a minor revolt underway against exotic high output alternator systems. Check the charge profile for conventional batteries, and you'll see what I mean. On the ICW you have plenty of run hours for recharge. A fine reliable Honda generator is cheaper than a 150 amp Alt. set-up. Rebuttles are welcome.
Phil

[mitiempo]

Not only are gel and agm batteries expensive but they often do not last as long as good flooded 6 volts. Agm batteries really need a full upgrade of the alternator and regulator as well.

I prefer solar over a Honda gen - quieter.