The best way to ensure you can always start the engine is to have a dedicated starting battery that is directly connected to the starter motor solenoid and serves no other purpose. Connecting to the house bank through a switch will provide a means of emergency starting if the engine battery suddenly croaks, or you kill the house battery in a forgetful, over-served moment and need some emergency power from the engine start battery for the house load.
Rich Knowles LF 38 in Halifax (For sale) Nanaimo, BC > On Feb 3, 2015, at 03:10, Josh Muckley via CnC-List <cnc-list@cnc-list.com> > wrote: > > Mark, > > Just keep in mind that the voltage method is not very accurate...though > neither are the A-hr meters if they are not periodically recalibrated. That > being said, I believe that my method errors on the conservative side. > > Just in case I do forget (or lose my shore power) I installed a Priority > Start device which will monitor battery voltage and then disconnect prior to > dropping below the requisite voltage to start the engine. A low battery and > difficulty starting can also be assisted by decompressing the engine. > > http://www.prioritystart.com/ > > Josh > >> On Feb 2, 2015 1:57 PM, "Dr. Mark Bodnar via CnC-List" >> <cnc-list@cnc-list.com> wrote: >> Josh, >> Thanks for the info on using voltage to gauge battery level. >> With my tiny bank and very limited loads it does not make sense to be wiring >> in a monitor or Balmar Smart Gauge (to the tune of $360 cdn). But I was >> thinking about adding a voltmeter so I could maintain some track on drain. >> Say something like >> http://www.amazon.com/DROK-Voltmeter-3-50-30-0V-Anti-reverse-Protection/dp/B00DUTJXWO/ref=sr_1_8?s=automotive&ie=UTF8&qid=1422902563&sr=1-8&keywords=voltage+meter&pebp=1422902722997&peasin=B00DUTJXWO >> >> I have to hook up and figure out how to mount my solar panel this spring, >> and I will re-wire my 1-2-off switch as per MaineSail's instructions. >> Rather than going to a "starting bank" and a "house bank" - I'll likely >> stick with A bank and B bank - use them interchangeably for starting and >> house. >> >> Mark >> >> >> >> There is no cure for birth and death save to enjoy the interval. >> - George Santayana >> On 2015-02-02 1:20 PM, Josh Muckley via CnC-List wrote: >>> What you are looking for is an amp-hour meter. Discharging a flooded deep >>> cycle battery rated at 100 Ahrs below 50% should be avoided. This roughly >>> equates to 50 Ahrs of use. 5amp for 10hours or 50 amps for 1 hour....you >>> get the jist. Discharging a flooded deep cycle below 50% will decrease its >>> effective useful service life. Many batteries publish a the number of >>> cycles and depth of discharge. One loose rating convention is that a deep >>> cycle will survive 200 charge/discharge cycles of 50%. The cycle number >>> increases when the depth of discharge is reduced. >>> >>> When using a voltage meter, it is important to take a "no load" voltage >>> after the battery has had time to "recover". The easy way to remember a >>> capacity to voltage conversion is 0.1v per 10%. A fully charged battery >>> will read 12.7v and a fully discharged one will read ~11.7v. By this >>> convention one should avoid voltage readings below 12.2v. I have a total >>> of 500Ahrs between 2 banks so when one gets to a "loaded" voltage of 12.2v >>> I start considering a switch to the other battery. I can go about 2 days >>> in the middle of summer with no charging source before I start to worry. >>> The engine charges at 100amps so motoring on and of the hook keeps me >>> pretty well topped up. >>> >>> I put one of these in my first sailboat. It is similar to the Link 2000 >>> that Edd suggested. I have a Link 2000 installed on my current boat but it >>> has never worked right. I believe the current shunt is bad or somehow >>> bypassed on the charge or discharge circuit.....I'll get to it... >>> >>> http://www.altestore.com/store/Meters-Communications-Site-Analysis/Meters-Battery-Monitors/Ammeters-Voltmeters-Battery-Monitors/Bogart-Engineering-TM-2025-A-F-TriMetric-Meter-Includes-fuse-and-fuse-holder/p10112/ >>> >>> Josh Muckley >>> S/V Sea Hawk >>> 1989 C&C 37+ >>> Solomons, MD >>>> On Feb 2, 2015 8:27 AM, "David Knecht via CnC-List" >>>> <cnc-list@cnc-list.com> wrote: >>>> Looking at the wiring diagrams reminded me of a question I am sure this >>>> list can answer. I have not done much cruising yet, but plan to do more >>>> in the future. One of the things I am unsure of is how people monitor the >>>> state of their batteries when you know shore power is not going to be >>>> available. I have a digital voltmeter on the panel that I can check the >>>> batteries and a chart that translates voltage into percent charge and I >>>> have used that as a rough guide, but that seems crude for such an >>>> important function. My understanding is that you have let the batteries >>>> sit for a while if they have been charging to get an accurate reading. I >>>> am not sure if current draws also have to be off. For instance, how >>>> would I know if it is safe to run the refrigeration while sailing to the >>>> next destination? Can you get a meter that gives you “hours of battery >>>> life remaining”? What strategies to listers use to solve this problem? >>>> Thanks- Dave >>>> >>>> Aries >>>> 1990 C&C 34+ >>>> New London, CT >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> >>>> 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 >
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