Charging and battery use questions

C

chpsk8

Member
Dec 1, 2012
145
MN
Boat Info
1990 310 Sundancer DA
Engines
Twin 5.7 Mercruiser w/ Alpha One
I went out saturday and beached. We ran the radio for two hours, and the fridge was on for 6 hours. I had to fire the starboard motor three times to power up on the beach (water on the river was rising throughout the day).
When we went to leave the starboard battery was too weak to fire the motor. I had the switch on 1 the whole day. I switched it to All, but even that wasn't enough and I had to fire the portr motor and I had to use the emergency start switch ( thank you whoever the genius was that put that in the design specs!).
At the end of the day I put it back in the slip, plugged in and turned on the converter/charger.
This morning I went to start the boat and had it on 1 and all I got was a click. I switched to both and it fired up.

So obviously I taxed the house battery pretty good and I'm planning on upgrading, but I want to make sure I know what I'm doing with the current system until then.

The boat has three new batteries this spring, nothing special, but decent size.

When I had the battery on 1 and it didn't start, should I have put it to 2, or was All the right move even though it didn't start. Did putting it in All move some juice to the dead battery, but suck the 2 battery down also? I did lag a couple minutes between switching and starting.

Should I be shutting off the battery switches when charging on the dock or leaving them on?

Thanks for your thoughts.
 
Engine batteriers should never be charged ,they are only supposed to start the engine(s) Each engine must have its own dedicated battery. The engines alternators will keep the motor batteries charged.
twin engines should be stand alone systems, never combined. You really should have dedicated house batteries to run everything 12V.
You need to determine how the switches are wired. the preferred method is using 3 battery switches. If its confusing pm me for my cell.
main cables from the starter goes to common on all switches
port 1 stbd 1 genereator 1
battery charger wired to #2 position on both engine switches switches and gen switch
#2 port connected to stbd #2 position connected to #2 gen switch
How it works:
normal starting is position #1 on all switches,
one engine not starting: engine switches to "both/all". this combines both engine batteries together to start a motor, can also include genny and house batteries, plus engine batteries to start a motor
charger could be used to charge the house system only, but again the charger dosent need to be on all the time. a lot of calls are for dead batteries because constant charging boils a battery dry if the charger malfunctions. Bad batteries never show up if constantly on a charger untill you anchor up for a few and cant start your motor because all 3 batteries were boiled dry and you got the start leaving the dock.
 
Last edited:
I should clarify what I have for a setup.
Port motor has its own battery and an on/off switch that controls no 12v functions like lights or water.
Starboard motor has a switch that is 1-all-2.
This is the one I need to figure out I'm thinking. It appears that any position will run the house or start the boat. Sounds like it should have a function like turning it to 2 and not having the house run, but only starts the motor.

Am I understanding correctly that the charger is only charging the one house battery and not the other two starter batteries?
 
Yep, only the house system is on the charger. I`d be more concerned if both electrical systems are tied together.easy to test by hooking up only 1 battery and seeing what works and what dosent.
start with the port . do the stbd gauges activate with the port gauges?
Does port start only work port starter? does stbd start only work stbd starter? do the stbd gauges activate?
do the same for the stbd, only connect that battery and see what works and what dosent.
also see what 12v systems are on what battery
 
Sorry, BT Doctur, but what?

My boat (a 2000 310) has 3 batteries, 1 for the port engine (and all cockpit electronics, including lights) and 2 for the starboard engine and all "house" electronics. The port battery charges off the port alternator, and the starboard bank charges off of the starboard engine. All 3 batteries are connected to the charger, not just "house". I have two On/Off battery switches (no 1/2/1+2 house configuration).

I'm not sure if you are describing some idealized battery configuration, but it sure doesn't relate to ANY of the real world applications I've seen. Admittedly, I don't have tons of experience with different boats over many years, but I've been doing a LOT of reading, and that's just not what I've seen anywhere.
 
src said:
Sorry, BT Doctur, but what?

My boat (a 2000 310) has 3 batteries, 1 for the port engine (and all cockpit electronics, including lights) and 2 for the starboard engine and all "house" electronics. The port battery charges off the port alternator, and the starboard bank charges off of the starboard engine. All 3 batteries are connected to the charger, not just "house". I have two On/Off battery switches (no 1/2/1+2 house configuration).

I'm not sure if you are describing some idealized battery configuration, but it sure doesn't relate to ANY of the real world applications I've seen. Admittedly, I don't have tons of experience with different boats over many years, but I've been doing a LOT of reading, and that's just not what I've seen anywhere.
Click to expand...

I concur, my battery set-up is the same and the charger charges all the batteries. It is a fairly typical installation....although if you have 3 batteries you should have one battery switch (port) that is "on/off" and one battery switch (stbd) that is "1/2/both/off"
 
GrandMaster said:
I concur, my battery set-up is the same and the charger charges all the batteries. It is a fairly typical installation....although if you have 3 batteries you should have one battery switch (port) that is "on/off" and one battery switch (stbd) that is "1/2/both/off"
Click to expand...

Thats the way mine is also
 
Ok guys with the 1,2,both, off switches.

how should I set mine for beaching and hanging out? Currently I set it on 1. When I am out running around and no motor off time I leave it on both. Is that the best way?

Went out today and didn't run radio or fridge and had no issues starting, but sure would like to run some music at least and the fridge would be great.
 
How many batteries do you have? If you just have 2, then try the odd/even method. On odd days, use 1, on even days, 2. That way you exercise your batteries evenly, and don't continually run one down, which shortens the life.

If you have 3 batteries, find out which bank (1 or 2) has two batteries on it and use that one.

Either way, check your batteries and make sure that (a) they are good and (b) all cells are full. Even "sealed" batteries can go dry. Also, "nothing special" batteries might not be up to the load you are asking them to carry, especially if you are running off a single battery for extended periods.
 
GrandMaster said:
I concur, my battery set-up is the same and the charger charges all the batteries. It is a fairly typical installation....although if you have 3 batteries you should have one battery switch (port) that is "on/off" and one battery switch (stbd) that is "1/2/both/off"
Click to expand...

I agree also, either that or companies like Promariner are selling a lot of 2 & 3 bank chargers that we can't use.
 
Your all missing the point of chpsk8 issue. He really dosent know how he`s wired.
what if the fridge is on the port system and the stero and lights are on the stbd system?
you have 2 dead batteries, dead MOTOR BATTERIES.
If the emer start solenoid is wired to the dead battery, it wont work either. Thats the reason to wire the batt switches the way I posted.
Given the electronics in todays boats, a true independent system is required
http://www.*******.com/merc/Bullet/97/97_05.pdf replace the *`s with b,o,a,t,f,i,x no comma`s.explains the need for engines and batteries
Recommendations
Batteries: Boats with multi-engine EFI power packages require each engine to be connected to
its own battery. This ensures that the engine’s Electronic Control Module (ECM) has a stable voltage
source.
Battery Switches: While engines are running, battery switches should be positioned so each
engine is running off its own individual battery. DO NOT run engines with battery switches in
“BOTH” or “ALL” position. In an emergency, another engine’s battery can be used to start an
engine with a dead battery.



EFI Electronic Control Module (ECM): The ECM requires a stable voltage source. During multiple
engine boat operation, an electrical onboard device may cause a sudden drain of voltage at the
engine’s battery. The voltage may go below the ECM’s minimum required voltage. Also, the idle
alternator on the other engine may now start charging and this could cause a voltage ‘spike’ in
the engine’s electrical system. In either case, the ECM could shut off. When the voltage returns
to the range that the ECM requires, the ECM resets itself. The engine will now run normally. This
ECM shut down usually happens so fast that the engine just appears to have an ‘ignition miss’.

 
BT Doctur, that may be a recommended wiring method, but it isn't how boats are wired from the factory, or it certainly didn't used to be. Also, I think you may be overly strict in your interpretation of the phrase "connected to it's own battery". Yes, each engine should be wired to a separate bank, but the common wiring setup is that one of the banks is used for both an engine and the house circuit.

Absolutely, he has to find out how his boat is wired, but I seriously doubt he has 3 different circuits (1, 2, House), and unless it was re-wired after the factory, I can almost guarantee that the charger circuit includes all batteries/banks. Looking at the manual for his boat, it shows either 2 or 3 batteries, depending on options ordered, and only 2 battery switches.

The wiring you describe might be an ideal, but I've never heard of it being used in real life on boats like ours, and certainly not from the factory.
 
chpsk8 said:
Ok guys with the 1,2,both, off switches.

how should I set mine for beaching and hanging out? Currently I set it on 1. When I am out running around and no motor off time I leave it on both. Is that the best way?

Went out today and didn't run radio or fridge and had no issues starting, but sure would like to run some music at least and the fridge would be great.
Click to expand...

First make sure that all of the house electrical power comes from the 2 battery side. Have the single battery side turned off and the 2 battery side set to 1 or 2 and just go through the boat checking all of the 12v items

Once thats confirmed, when the boat is running both engines I would have ALL batteries switched on. When you park it, single battery off, and just one battery on the double side on. That way you should always have a good battery on each side to start the engines when its time to leave.

Personally I cant figure out what Bt Doctur is trying to say. If you had one battery not connected to any engine how would you charge it while underway without running a genny?
 
I have 2 batteries, 1 motor. I keep the battery switch on 1 all the time. The 2nd battery I keep fresh and there only so I can flip the switch over to 2 in the event that I run batt 1 down enough that it won't start.

I know, doesn't apply at all to this situation.
 
Ok, I have the same setup as everyone else, except Bt Doctor. My question is which battery does the GEN start off of? How does the EMERG Start switch work? I have killed battery's on both sides at different times and it always works. Is it smart, as in it looks for the best battery and connects it to the start circuit?
 
Since this thread just made me go back and look at my wiring diagram, I just learned something...

Apparently my shower sump pump is connected to the the PORT battery switch. So my theory of turning off the port battery switch while on the hook would be bad if taking a shower or running the AC. It is the only thing connected to the Port battery switch. However the high-water bilge pump and the stereo memory are connected directly to the Port battery.

Good to know that one bilge pump is connected to the Stbd batteries and one to the Port battery.
 
My genny run a off the house battery which is port I know this when my port batteries were junk and I had to start my starboard and the. Use my emergency start to charge them because my genny would not crank after I had the port engine running I started genny. Now I won't run my house down that low anymore since I replaced my batteries.
 
Thanks guys, looks like I have some experimenting to do.
I played a little with the 1-2 all switch today. It appears I can run the house or start the starboard side in any position. I need to spend some time really playing with it, but the little biti played that's the impression I get.
I'll post what's find.
 
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