My question is is it recommended to leave main battery and start battery activated while under power and sail in my Hunter 38? Also, is it recommended to leave only main battery on while not under sail but shore power? I do have an inverter so maybe it makes no difference here but everyone I ask approaches this question differently. In essence, is there a proper way to operate my batteries? Thank you.
Battery operation
- Thread starter carriemeaway
- Start date
Do you want your fridge to stay cool and instruments active? then one would have the house bank on, the charger/inverter has (2) functions the inverter allows for the use of limited (depending on the capacity of the inverter) 120V circuits on the boat while not on shore power, while the charger function restores the house and start battery to full charge when on shore power. While under motor power the circuit will charge both the house and start batteries. Batteries in my opinion are a consumable, every so many years you must replace them as they do wear out, longevity is directly related to the voltages at which the batteries are charged and the regular maintenance of ensuring that the electrolytes are at the proper level. I don't believe that turning the batteries off will help much with the life cycle, charge voltages, temperature compensated charge voltages more specifically are of the utmost importance to battery longevity.
I know it's stupid to assume, but in this case I'm guessing you mean "Batteries never off" while you are physically on the boat. I've read, and been told, that one should never leave a boat with the battery switches on.
Why would that be??? I leave my batts on, so the automatic bilge pumps will work, the solar will keep them charged, etc.
If you every disconnected your batteries from your alternator while it's running, it would cease to function because you'd blow your diode(s) on the alternator.
I think you need to describe your system CarrieMeAway.
How many batteries? What size
What do you mean by "activated"?
How are batteries differentiated "Main" and "Start"? How is it wired to the engine?
Does your AC shorepower charger have independent charging for 2 (or 3) banks of batteries?
Etc., etc.
I think you need to describe your system CarrieMeAway.
How many batteries? What size
What do you mean by "activated"?
How are batteries differentiated "Main" and "Start"? How is it wired to the engine?
Does your AC shorepower charger have independent charging for 2 (or 3) banks of batteries?
Etc., etc.
GorrilaToast; I've read, and been told, that one should never leave a boat with the battery switches on.
GorrilaToast; I think, as JViss points out, that's not a general practice. It may applicable in your situation. Many boats have the bilge pump wired directly from a battery (or bank of batteries) so the selector switch is not controlling the bilge pump -- Then, if you leave a boat on a mooring, or don't have a shorepower charger, don't have ongoing refrigeration, etc., then shutting off the selector switch may be advantageous. However, unless your really shutting the systems down, you would be less likely to do that.
GorrilaToast; I think, as JViss points out, that's not a general practice. It may applicable in your situation. Many boats have the bilge pump wired directly from a battery (or bank of batteries) so the selector switch is not controlling the bilge pump -- Then, if you leave a boat on a mooring, or don't have a shorepower charger, don't have ongoing refrigeration, etc., then shutting off the selector switch may be advantageous. However, unless your really shutting the systems down, you would be less likely to do that.
Connecting direct to the batteries, one can leave isolator switches off. ON starting run under load till fully warmed up to normal. Have solar panel linked to each battery
Nope never off. Boat sits in canal behind my house. I am on and off the boat all the time. I want lights to be working, etc. Never touch the selector switch. I do leave the shore power disconnected unless I want to charge the batteries or run the A/C.
A lot depends on the equipment on board and usage. However, the newer boats have indicators how much capacity each battery is at. This is crucial knowing what is there. However, when under sail, I have always told my customers to leave the house battery on and the engine battery off. Why? What if you leave your batteries on without any charging of sorts and both fall below the point that you cannot start your engine? Then you are in a sense in deep crap if returning to dock without an engine. Again a lot depends on how the boat is rigged along with charging for example, solar but many do not have that. Food for thought.
It all depends on how it is wired.
These two replies clearly indicate this.
carriemeaway, you need to study the electrical design and installation of your boat to understand how it works. DayDreamer41 explained how an inverter works.
What many of us have done is to route ALL charging sources to the house bank, so that the selector switches become USE only switches, rather than both charge and use switches (i.e., if the charging sources require that the switches be activated to designate which batteries get charged.)
You may be interested in these:
OEM 1-2-B Switch Wiring History http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101
Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html
This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615
This is a newer primer for boat system wiring design with a thorough digram: Building a Good Foundation (October 2016)
http://forums.sailboatowners.com/in...dc-electrical-foundation.181929/#post-1332240
The Short Version of the 1-2-B Switch Stuff: http://c34.org/bbs/index.php/topic,5977.msg38552.html#msg38552 This is a link to the Electrical Systems 101 Topic, reply #2
Probably several right or at least adequate answers to this one. 
We have left our house bank 'on' year-around, for over 20 years. Our house bank lasts about 9 years (pair of Trojan GC batteries). The charger is left on all the time to 'float' the batteries when at the dock. The battery powers the main panel and that keeps the bilge pumps and refrigerator both 'on' all the time. Some other loads, several very low amp-draw measuring devices, are tied to the + terminal and are fused at that point with a Blue Seas terminal block.
We do not have a hard-wired inverter, both for reasons of safety, cost, and complexity.
Our stock 50 amp Moto alternator charges the batteries when cruising.
We also have an Optima brand AGM emergency battery that we "test start" the engine with several times a year. It is over ten years old, and also gets a float charge at the dock.
We have left our house bank 'on' year-around, for over 20 years. Our house bank lasts about 9 years (pair of Trojan GC batteries). The charger is left on all the time to 'float' the batteries when at the dock. The battery powers the main panel and that keeps the bilge pumps and refrigerator both 'on' all the time. Some other loads, several very low amp-draw measuring devices, are tied to the + terminal and are fused at that point with a Blue Seas terminal block.
We do not have a hard-wired inverter, both for reasons of safety, cost, and complexity.
Our stock 50 amp Moto alternator charges the batteries when cruising.
We also have an Optima brand AGM emergency battery that we "test start" the engine with several times a year. It is over ten years old, and also gets a float charge at the dock.
Important choices here to note. This skipper keeps his fridge on all the time, so the switch MUST remain on.
Many of us choose to not have anything running when we're away from the boat, so we keep the switch OFF when away and wire the bilge pump to an always on bus direct to the batteries with fuses and perhaps a switch.
I sometime run the fridge the night before I cast off, so leave the switch and fridge ON.
Please note that this is a personal and MANAGEMENT choice, and is NOT a "one-size-fits-all" answer to the OP question.
I'm in a small marina with some questionable vessels. What I mean is boats that you never see a person onboard but are always hooked to shore power some running ACs and fridges all the time. I don't like the thought of being hooked up to all these boats. I have four 6v Trojans for house and a 24 group 12v for starting. I only hook up once a month for a day or two to top off the batts. I am at the boat almost everyday and take her out at least once a week running the engine about 2 hours each time. I check the batts condition monthly and keep the water level up. I keep the selector switch on OFF as I have nothing running when I leave the boat. Bilge pump is wired directly to house bank. So far this has worked and I get at least ten years of use out of the batts. My question is, is my thinking flawed or should I go with the, "if it ain't broke don't fix it" mindset?
What you do is what I do. I think it's just fine. No need to change. Even if you're in a "good" marina, your approach makes sense. Only add? Try a small solar panel for those days you're not there. I do and it keeps my voltage reasonable w/o being plugged in.
My "Smart" charger connects directly to the batteries and is wired to the shore power. I try to remember to turn the batteries off before leaving the boat - sometimes for days. Bilge pump is wired directly and is with a float switch. I turn them off because I perceive there is less risk of electrical fire with it off. I'd like to say all my wires are protected by proper fusing but I just got the boat in June. Just figuring stuff out.
I hand yet to trace this on my new to me O'Day 322, but I think the PO wired the battery charger through the 1-2-both-off switch. I say this because I don't see the battery charger wires connected directly to the batts, and although the charger has 2 sets of leads, only one is used.
So, until I can figure this out, I leave the 1-2-both-off switch on "both" when on shore power (to make sure both batts are getting charged.
When sailing, I may use one batt or the other, just to keep one in reserve. But usually when out for a few hours day sail, I just leave it on both.
I like to keep the beer cold, so I always have a battery on to run the fridge. Having VHF, wind instruments, stereo and other electronics on is second priority behind keeping the beer cold!
Greg
So, until I can figure this out, I leave the 1-2-both-off switch on "both" when on shore power (to make sure both batts are getting charged.
When sailing, I may use one batt or the other, just to keep one in reserve. But usually when out for a few hours day sail, I just leave it on both.
I like to keep the beer cold, so I always have a battery on to run the fridge. Having VHF, wind instruments, stereo and other electronics on is second priority behind keeping the beer cold!
Greg