Batteries #1 #2 or both
- Thread starter MerSea
- Start date
- Status
All Three
I normally start on #2. #2 is reserved for starting. #1 is for house power. #1 or both when I'm running for charging. #1 is a deep cell. #2 is a starting battery. Don't leave them connected all the time. One or both can be damaged. Bill
I normally start on #2. #2 is reserved for starting. #1 is for house power. #1 or both when I'm running for charging. #1 is a deep cell. #2 is a starting battery. Don't leave them connected all the time. One or both can be damaged. Bill
Our scheme
I have two batteries (both deep cycle 115 AH marine batteries). We leave them on BOTH when charging, starting, and running the engine. We switch to either #1 or #2 after the engine is stopped and we're sailing along. Our method is to use #1 on odd-numbered days and #2 on even numbered days to sort of spread the load. There are better schemes involving different starting and house batteries, battery isolators and combiners, etc. but this works for us (as long as I remember to switch from BOTH to only one of the batteries when I turn the motor off). Gary
I have two batteries (both deep cycle 115 AH marine batteries). We leave them on BOTH when charging, starting, and running the engine. We switch to either #1 or #2 after the engine is stopped and we're sailing along. Our method is to use #1 on odd-numbered days and #2 on even numbered days to sort of spread the load. There are better schemes involving different starting and house batteries, battery isolators and combiners, etc. but this works for us (as long as I remember to switch from BOTH to only one of the batteries when I turn the motor off). Gary
You should have a starting battery
You really should have a dedicated battery that is rated as a "Marine Starting Battery". Using a deep-cycle battery to start your engine will prematuraly shorten the battery's life. Conversely, a starting battery should not be used for house loads. The two types of batteries are very different and should not be mixed. That said - use the starter to start - the deep for houseloads and when the engine is running - its good to keep it on "both" as both batteries are geting charged.
You really should have a dedicated battery that is rated as a "Marine Starting Battery". Using a deep-cycle battery to start your engine will prematuraly shorten the battery's life. Conversely, a starting battery should not be used for house loads. The two types of batteries are very different and should not be mixed. That said - use the starter to start - the deep for houseloads and when the engine is running - its good to keep it on "both" as both batteries are geting charged.
Rob
"Using a deep-cycle battery to start your engine will prematuraly shorten the battery's life." Is that true? Why? Thanks
"Using a deep-cycle battery to start your engine will prematuraly shorten the battery's life." Is that true? Why? Thanks
Complex Subject
Richard - It's a rather complex subject - battery design. I recommend reading one of Caldors books on the subject. Basically the lead plates that make up the cells have different design for various applications. A starting battery is designed for short burts of high amp draws. Long shallow draws (i.e. house loads) are better suited for the design of a deep-cyle battery. Again - it in the internal design of the plates which are very different between to two designs. A Marine deep cycle/starter is probaly a good alternative if you want the best of both worlds in one (although I am confident a dedicated starter-type battery for starting and a deep cycle for house is probaly better). Good luck - Rob
Richard - It's a rather complex subject - battery design. I recommend reading one of Caldors books on the subject. Basically the lead plates that make up the cells have different design for various applications. A starting battery is designed for short burts of high amp draws. Long shallow draws (i.e. house loads) are better suited for the design of a deep-cyle battery. Again - it in the internal design of the plates which are very different between to two designs. A Marine deep cycle/starter is probaly a good alternative if you want the best of both worlds in one (although I am confident a dedicated starter-type battery for starting and a deep cycle for house is probaly better). Good luck - Rob
You do not need a starting battery
When the wife is running the hair dryer, (1000W @120V = 83.3 amps at 12 volts to the inverter) the deepcycle house battery sees an 83 amp load for about 3-5 minutes. When I hit the start buttion on a 35 HP engine the start battery sees 50-60 amps for 10 seconds. Can somebody tell my why I HAVE to have a marine starting battery when my deepcycle battery is already being taxed way beyond what a starter motor will put on it with my wife's hir dryer???? Gary K's setup is best. It is what I use and I have never had ANY problems. Then you don't have to concern yourself with different types of batteries fighting each other because of voltage and AH differeces.
When the wife is running the hair dryer, (1000W @120V = 83.3 amps at 12 volts to the inverter) the deepcycle house battery sees an 83 amp load for about 3-5 minutes. When I hit the start buttion on a 35 HP engine the start battery sees 50-60 amps for 10 seconds. Can somebody tell my why I HAVE to have a marine starting battery when my deepcycle battery is already being taxed way beyond what a starter motor will put on it with my wife's hir dryer???? Gary K's setup is best. It is what I use and I have never had ANY problems. Then you don't have to concern yourself with different types of batteries fighting each other because of voltage and AH differeces.
Depends
I routinely start with the starting battery and it's used only for starting. I have forgotten to switch and used the deep cycle for starting. I have also used both to start when neither battery had enough charge to start and had good results. BUT!!!! if one battery is fully charged and the other pretty much dead putting on both will rapidly drain the good battery. As a last resort for starting with a low battery I have been sailing at 4-5 knots and been able to start with a low battery by putting the transmission in gear. This is not a recommended procedure but it has worked. What happend was we were sailing all day and hadn't motored much and when we stopped the motor tht morning we didn't switch to the house battery. When we were getting close to the marina I tried to start but couldn't with either battery alone or with both in neutral. But when I had it on both and in gear it started right up. We were sailing along pretty fast and we have a large three blade prop. There was not detectable harm tothe engine or transmission but it probably isn't a good way to start kinda like pushing a car to start the engine.
I routinely start with the starting battery and it's used only for starting. I have forgotten to switch and used the deep cycle for starting. I have also used both to start when neither battery had enough charge to start and had good results. BUT!!!! if one battery is fully charged and the other pretty much dead putting on both will rapidly drain the good battery. As a last resort for starting with a low battery I have been sailing at 4-5 knots and been able to start with a low battery by putting the transmission in gear. This is not a recommended procedure but it has worked. What happend was we were sailing all day and hadn't motored much and when we stopped the motor tht morning we didn't switch to the house battery. When we were getting close to the marina I tried to start but couldn't with either battery alone or with both in neutral. But when I had it on both and in gear it started right up. We were sailing along pretty fast and we have a large three blade prop. There was not detectable harm tothe engine or transmission but it probably isn't a good way to start kinda like pushing a car to start the engine.
You don't HAVE to
as a deep cycle battery will start your engine without damage. However, with respect to Gary K's set up I'd suggest two improvements: 1. Arranging two banks with dedicated On-Off switches and a combiner means never waking up at anchor with TWO dead banks because you forgot to switch from the Both setting after you finished motoring. Yeah, I know, you guys would NEVER forget, right?
2. Cycling between two mirror house banks "to spread the load" isn't better for the individual batteries. In fact, since batteries discharge at a non-linear rate dependent the load/capacity ratio if you apply the same load to a big bank and one that is 50% smaller the smaller bank will reach discharge MORE than twice as fast as calculated by Peukert's formula. That produces more discharges over the life of the battery and a shorter life, not to mention recharging more often. Recharging is the same deal. That bigger bank will accept a greater ratio of charge with respect to it's size. That's why for an optimized set up you'll want a bank that is SIZED for a house load (and it's charge/discharge regimen) and a starter bank that is appropriately sized for it's load. Combining a starter bank and deep cycle bank during charging will not compromise either bank. Combining different types (wet/gel/AGM) will.
as a deep cycle battery will start your engine without damage. However, with respect to Gary K's set up I'd suggest two improvements: 1. Arranging two banks with dedicated On-Off switches and a combiner means never waking up at anchor with TWO dead banks because you forgot to switch from the Both setting after you finished motoring. Yeah, I know, you guys would NEVER forget, right?
2. Cycling between two mirror house banks "to spread the load" isn't better for the individual batteries. In fact, since batteries discharge at a non-linear rate dependent the load/capacity ratio if you apply the same load to a big bank and one that is 50% smaller the smaller bank will reach discharge MORE than twice as fast as calculated by Peukert's formula. That produces more discharges over the life of the battery and a shorter life, not to mention recharging more often. Recharging is the same deal. That bigger bank will accept a greater ratio of charge with respect to it's size. That's why for an optimized set up you'll want a bank that is SIZED for a house load (and it's charge/discharge regimen) and a starter bank that is appropriately sized for it's load. Combining a starter bank and deep cycle bank during charging will not compromise either bank. Combining different types (wet/gel/AGM) will.Great system (until...)
I wanted to chime in and agree with Tom, Bill and Gary. Used Gary's method for many years. Works great, until you forget to take if off of "Both", or not charge the 'off' battery enough. Anyways, to Bill's question, you don't have to have a starter battery. I agreed with that approach until last year; yes, I am adding a starter battery with all its inherent problems. At least I'll know that one source of juice will always be available (in case I get into the juice and leave lights on again...or whatever). Many good sailors do without a starter battery and have better memory and skills than I. To MerSea's question, already answered, but start using one and keep the second in reserve. Use Gary's method to make sure both are charged. Paul
I wanted to chime in and agree with Tom, Bill and Gary. Used Gary's method for many years. Works great, until you forget to take if off of "Both", or not charge the 'off' battery enough. Anyways, to Bill's question, you don't have to have a starter battery. I agreed with that approach until last year; yes, I am adding a starter battery with all its inherent problems. At least I'll know that one source of juice will always be available (in case I get into the juice and leave lights on again...or whatever). Many good sailors do without a starter battery and have better memory and skills than I. To MerSea's question, already answered, but start using one and keep the second in reserve. Use Gary's method to make sure both are charged. Paul
Back up
I keep a portable jump starter charged up and on the boat in case my regular batteries fail. It also provides a source of power to my 10" tv/dvd player while anchored.
I keep a portable jump starter charged up and on the boat in case my regular batteries fail. It also provides a source of power to my 10" tv/dvd player while anchored.
Battery #1 is dead
Update This morning I went to the marina and tried to start on #1 ,nothing the battery was dead... West Marine here I come. I have been sailing for over 30 years ( 470 dinghy and Hobie-cat 16) ; 2 years ago we bought a H27 and most of the mechanical and electrical issues are kind of new to me ,but I am not doing to bad around the buoy I like to thank every body for their replies,as always this forum has been very helpful. Phil.
Update This morning I went to the marina and tried to start on #1 ,nothing the battery was dead... West Marine here I come. I have been sailing for over 30 years ( 470 dinghy and Hobie-cat 16) ; 2 years ago we bought a H27 and most of the mechanical and electrical issues are kind of new to me ,but I am not doing to bad around the buoy
I like to thank every body for their replies,as always this forum has been very helpful. Phil.
Both Batteries
I have been starting my boats with 2 deep cycle batteries for a span of 16 years. Bateries have lasted about 6yrs. I also keep charger on 24/7 even when I am gone for a week or more. I only sail in summer and garage bateries in winter.I know others wouldn't advise this arrangement but it works for me.
I have been starting my boats with 2 deep cycle batteries for a span of 16 years. Bateries have lasted about 6yrs. I also keep charger on 24/7 even when I am gone for a week or more. I only sail in summer and garage bateries in winter.I know others wouldn't advise this arrangement but it works for me.
Solar, wind, alternator, shore power charger
They charge the batteries, you should have all your batteries tied into which ever "charging device" you are using at the moment. The real question is how do I manage the system when I have 2 or more charging devices working at the same time. My solution is I turn off all but the biggest or the one I can't turn off. So when I start my engine, I turn off the wind gen and or solar panel. Of course now we are back to "flipping switches" to manage our batteries and from what I am reading on the post, most just want to "have a device handle it for me". More stuff to break and leave me high and dry. I'd recommend adding this kind of procedural stuff to your "boat operations" check lists. That way the brother-in-law will not be able to get himself (and your boat) into trouble as easily.
They charge the batteries, you should have all your batteries tied into which ever "charging device" you are using at the moment. The real question is how do I manage the system when I have 2 or more charging devices working at the same time. My solution is I turn off all but the biggest or the one I can't turn off. So when I start my engine, I turn off the wind gen and or solar panel. Of course now we are back to "flipping switches" to manage our batteries and from what I am reading on the post, most just want to "have a device handle it for me". More stuff to break and leave me high and dry. I'd recommend adding this kind of procedural stuff to your "boat operations" check lists. That way the brother-in-law will not be able to get himself (and your boat) into trouble as easily.
- Status