I may be new to sailing but not to boats. My last boat had (3) 12V starting batteries and (2) 6V (in series) for the house bank. All deep cycle wet cell varying in age from one to six years. My current boat has only (2) 12V (age unknown) with nothing to charge them but the A-4. I have never experienced any amount of self discharge to the point of concern over any reasonable amount of time. I have always kept them on the boat over the winter and top them off and check fluid level in the beginning of the season. Last year I didn’t even do that and both engines (1970 GMC 427 Mercruisers) cranked over plenty strong after a winter on the boat. (that was right before I sold her and got my C&C 33)
A agree that the predictions of self-discharging over time have never in my experience come to pass. In response to the concern of spilling acid in a wet cell on a rail-in-the-water-heel, I think they made sealed no maintenance wet cell batteries. They do for uninterruptible power systems (UPSs). Airplanes, too I think. I will have to look into that. The old boat didn’t tip that much. From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Ken Heaton via CnC-List Sent: Wednesday, February 25, 2015 2:20 PM To: Della Barba, Joe; cnc-list Subject: Re: Stus-List Batteries -- Flooded, Sealed or AGM? "wet cells can lose up to 10% of charge per month" I've seen various outlandish quotes like that on the internet. They are pure BS. As I understand it, the storage temperature a flooded battery would have to be well in excess of 100 degrees Fahrenheit for this high rate of self discharge to happen. A quote from Maine Sail: "I was a total disbeliever at the resting OCV of a flooded battery that has sat 100% uncharged for nearly 9 months. I grabbed my refractometer and performed specific gravity checks on each cell. They all agreed and all agreed with the DVM at the SOC.. So this causes one to wonder why there is all the concern around self discharge> I have to assume that nearly 20-30 days of this summer saw the shed temps over 100F. It is uninsulated with a black roof... If we are to believe OCV and SG readings it puts this battery at approx 90% SOC after at least 9 months.. " Read the whole article here, it is worth the read: http://www.pbase.com/mainecruising/self_discharge Other references: http://www.cieux.com/bm/batteryWreck.html "Wet cells can maintain a workable charge for about a year after the last full charge. When cold, wet cells lose power and cannot deliver their rated charge. Instead of waiting a year for the battery to run down, either recharge your wet cell every six months or keep it fully charged all the time by putting a floating charge on it." http://jgdarden.com/batteryfaq/carfaq16.htm "Self-discharge is accelerated by temperature. For batteries that are over 77° F (25° C), the self-discharge rate doubles with a 18° F (10° C) rise in temperature. Thus, sulfation is a huge problem for wet lead-acid batteries not being used, sitting on a dealer's shelf, or in a stored vehicle, especially in HOT temperatures." Ken H. On 25 February 2015 at 14:29, Della Barba, Joe via CnC-List <cnc-list@cnc-list.com> wrote: One thing to keep in mind is wet cells can lose up to 10% of charge per month and gels only lose around 1%. For a boat on a mooring or otherwise off shore power this can be a factor. If you go wet cells on a mooring you will want a solar panel to keep them topped off. Joe Della Barba Coquina C&C 35 MK I From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Marek Dziedzic via CnC-List Sent: Wednesday, February 25, 2015 12:58 PM To: Edd Schillay; cnc-list@cnc-list.com Subject: Re: Stus-List Batteries -- Flooded, Sealed or AGM? Edd, I am not claiming to be an expert, but from what I have read so far, the AGMs might be a costly solution to a somewhat non-existing problem. Check Main Sail’s write ups on batteries (he did a few additional ones recently). If I understand these things correctly, the best performance per $ you will get from the wet cells (proper marine deep cycle ones). The longest duty cycle – from the golf batteries (the main disadvantage – they are higher than most other batteries, but this is for a reason – there is extra electrolyte over the plates and they don’t get uncovered when the boat heels). The most convenient – gel cells (few disadvantages of AGMs and most of the advantages of wet cells plus they don’t spill, don’t have issues with heeling angle and can be placed safely in the cabin). AGMs would require special care (when charging) and may not last that long. You may find interesting the results of the battery survey Main Sail did recently. Here is the link to his “early results”: http://forums.catalina.sailboatowners.com/showthread.php?t=168972. Or his take on the flooded deep cycle batteries here: http://www.pbase.com/mainecruising/deep_cycle_battery <http://www.pbase.com/mainecruising/deep_cycle_battery&page=1> &page=1 Marek From: Edd Schillay via CnC-List <mailto:cnc-list@cnc-list.com> Sent: Wednesday, February 25, 2015 12:16 PM To: C <mailto:cnc-list@cnc-list.com> &C List Subject: Re: Stus-List Batteries -- Flooded, Sealed or AGM? Josh, I’m leaning towards 4 to 6 (depending on the space available) Trojan T-105s, but am concerned about the maintenance, especially since I’m kinda cut off from the boat all winter long. Alternatively, I was looking at these AGMs: http://www.atbatt.com/amstron-gc2-6v-agm-deep-cycle-battery.asp?utm_content=Amstron-AP-GC2 <http://www.atbatt.com/amstron-gc2-6v-agm-deep-cycle-battery.asp?utm_content=Amstron-AP-GC2&utm_term=AP-GC2&utm_category=Sealed-Lead-Acid&gclid=CLy95KfH_cMCFXBp7Aod2WkA2g> &utm_term=AP-GC2&utm_category=Sealed-Lead-Acid&gclid=CLy95KfH_cMCFXBp7Aod2WkA2g, but won’t bother if AGMs are only going to last a few years. My charging system is the alternator, since the Enterprise lives on a mooring during the season (yes — we call that "standard orbit"). I only hook up to shore power a few times a year when cruising. The new system will connect the alternator to the house bank and use a Blue Seas ACR (https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A) to also charge the starting battery. That means I'll have a New-In-Box Echo Charger to sell this Spring. All the best, Edd Edd M. Schillay Starship Enterprise C&C 37+ | Sail No: NCC-1701-B City Island, NY Starship Enterprise's Captain's Log <http://enterpriseb.blogspot.com/> On Feb 25, 2015, at 11:53 AM, Josh Muckley <muckl...@gmail.com> wrote: I was at a point of extremes when I bought 5 AutoZone marine/deep cycle for a total of about $600 and 500Ahrs (~250Ahrs usable without damage). They are the standard maintenance free auto style which can be but are not intended to be watered. For me they were relatively cheap, readily available, easy to claim warranty, light enough to move/install/uninstall. They are also the easiest to charge and discharge since it is such a long standing standard. There are certainly advantages to other technologies and disadvantages to wet cells but for now this solution has met my needs very comfortably. T-105 golf cart batteries would really be my only other concideration but availability, movability, and warranty claimability are hold backs. You also have to consider the charging system when choosing batteries. I have a 100amp balmer alternator with external charge controller and a ProMariner P Nautic 60-12 charger/maintainer. There are disadvantages to staying on shore power 24/7 but it is working for me right now. Maybe I'll change that practice in the future. Josh Muckley S/V Sea Hawk 1989 C&C 37+ Solomons, MD On Feb 25, 2015 11:17 AM, "Edd Schillay via CnC-List" <cnc-list@cnc-list.com> wrote: Listers, As you know, I’m redoing the electrical systems on the Enterprise (thanks to all for diagrams and advice). So now comes the question of what type of battery to use in my house bank — Flooded, Sealed or AGM? What do you have on your C&C and why do you prefer it? And, if you have flooded, how often do you top them off with distilled water? The countdown has begun! http://enterpriseb.blogspot.com/2015/02/launch-of-enterprise-countdown.html All the best, Edd Edd M. Schillay Starship Enterprise C&C 37+ | Sail No: NCC-1701-B City Island, NY Starship Enterprise's Captain's Log <http://enterpriseb.blogspot.com/> _______________________________________________ Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go to the bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com _____ _______________________________________________ Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go to the bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com _______________________________________________ Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go to the bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com
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