I think ABYC is a little to conservative on this issue if that is their stance. "AGM's are advantageous anyplace where you need a reliable totally sealed battery for safety or environmental reasons - wheelchairs, medical standby power, inside RV's, computer room UPS systems, or in enclosed spaces in boats."
Bob Bob Boyer S/V Rainy Days / Annapolis MD 1983 C&C Landfall 38 - Hull #230 email: dainyr...@icloud.com blog: dainyrays.blogspot.com "There is nothing--absolutely nothing--half so much worth doing as simply messing about in boats." --Kenneth Grahame > On Nov 19, 2015, at 1:19 PM, ed vanderkruk via CnC-List > <cnc-list@cnc-list.com> wrote: > > Technically vapors are an issue. All battery types - wet/sealed/gel/AGM - are > subject to ABYC venting guidelines. There are some solutions - venting the > battery enclosure or having vented caps for wet cell directed overboard > somehow. > > Ed > >> On Nov 19, 2015 12:50 PM, "Robert Boyer via CnC-List" >> <cnc-list@cnc-list.com> wrote: >> I DO use AGMs--so, vapors are not an issue. I have some space just forward >> of the mast under the settee but close to the boat's centerline that might >> work for battery storage--I have to check out the dimensions but this would >> remove weight aft and add it close to the center of gravity. >> >> Bob >> >> Bob Boyer >> S/V Rainy Days / Annapolis MD >> 1983 C&C Landfall 38 - Hull #230 >> email: dainyr...@icloud.com >> blog: dainyrays.blogspot.com >> >> "There is nothing--absolutely nothing--half so much worth doing as simply >> messing about in boats." --Kenneth Grahame >> >>> On Nov 19, 2015, at 11:54 AM, Marek Dziedzic via CnC-List >>> <cnc-list@cnc-list.com> wrote: >>> >>> Bob, >>> >>> as you said, the current from the house batteries should never be high, so >>> the wires should not be an issue. However, if you calculate your load at 30 >>> A and select appropriate gauge of the wire (for distance), make sure that >>> you install an appropriate fuse (probably not larger than 50 A) (I would do >>> it right on the terminal, but ABYC says, within 6 or 7 in from the >>> terminal) to protect that wire. Such fuse would probably allow for one >>> quick start of the motor (it would not allow for cranking a cranky motor). >>> But if you want to be able to use your house batteries for cranking, you >>> have to allow for at least 80 – 100 A in that cable (i.e. appropriate >>> gauge). Keep in mind that if you install bigger cable, your voltage loss >>> would be less, so you would have more energy available to you lights and >>> instruments (instead of heating the cabin). >>> >>> One other thought. I am not sure if putting batteries under the V-berth is >>> the best idea. As much as you could, you should avoid placing heavy objects >>> far away from the centre of gravity. In heavy weather the heavy bow would >>> be your enemy, not a friend. >>> >>> And finally, at least theoretically, you should not install the normal >>> lead-acid batteries in the cabin (where they are not vented directly >>> outside). If you want to install batteries below, you should use the gel or >>> AGM batteries. This, in turn, leads to a more complex charging system >>> (especially, if you are going to use AGMs). >>> >>> just a few ideas to consider >>> >>> Marek >>> 1994 C270, “Legato” >>> Ottawa, ON >>> >>> >>> From: Robert Boyer via CnC-List >>> Sent: Thursday, November 19, 2015 11:24 AM >>> To: cnc-list@cnc-list.com >>> Cc: Robert Boyer >>> Subject: Stus-List Changing weight distribution in Landfall 38 >>> >>> I am equipping my boat for 8 months per year of cruising in the Bahamas. I >>> have added a 19-gallon auxiliary diesel tank where my holding tank was >>> located (under the navigation seat) which adds weight aft. I currently >>> have 4 group 27 batteries which will be eventually upgraded to Group >>> 31's--these also are located aft. >>> >>> I have been considering moving 2 or 3 batteries from the aft cockpit locker >>> to some dead space under the v-berth. This would take some weight from the >>> aft and add it forward. (My boat currently sits about 2" high at the bow >>> and maybe 1 inch low at the stern with no one aboard but full fuel tanks.) >>> >>> I could configure the batteries such that the new forward bank could be the >>> house bank and the starting bank (which I could probably reduce to 1 or 2 >>> batteries) could remain aft. My problem is sizing the cables that would >>> run from the forward batteries to the aft controls. As I see it, these >>> cables would never carry more than 30 amps (maximum charging from my solar >>> panels) unless I needed them for starting (in the event of a dead starting >>> battery). >>> >>> Does anyone have any comments or suggestions on this matter? >>> >>> Bob >>> >>> Bob Boyer >>> S/V Rainy Days / Annapolis MD >>> 1983 C&C Landfall 38 - Hull #230 >>> email: dainyr...@icloud.com >>> blog: dainyrays.blogspot.com >>> >>> "There is nothing--absolutely nothing--half so much worth doing as simply >>> messing about in boats." --Kenneth Grahame >>> >>> >>> _______________________________________________ >>> >>> 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 >
_______________________________________________ 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
