Start vs. House bank

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
4mo said:
That sounds perfect, so the Blue Sea Si-ACR automatic charging Relay - 12V DC 120a?

I wonder how to wire that with my battery monitor (victron bmv-700) on the house bank?
Click to expand...



I really don’t know what I’m talking about, so ignore me.

I had a sailboat that had 2 4D batteries and a 1/2/Both/Off switch. It sounds as if that is similar to what you have?

I think your plan of using the 4 GC batteries for the house is great and keeping a separate start bank for your motor and windlass.

However, I would scrap that 1/2/Both switch and use an ACR as you mentioned above. I would also direct all your charging sources to your house bank. This way there is no switching. When there is a charge source and the voltage rises to a certain level, the ACR combines the two banks and they are both charged. Typically, this would keep the start battery topped up while it charges the house. Also, if I am correct, this will provide the power to the start batteries that are driving the windlass from the alternator via the ACR.

Anyway, listen to those that know better than I but I think you are on the right track.
 
dhays said:
I really don’t know what I’m talking about, so ignore me.

I had a sailboat that had 2 4D batteries and a 1/2/Both/Off switch. It sounds as if that is similar to what you have?

I think your plan of using the 4 GC batteries for the house is great and keeping a separate start bank for your motor and windlass.

However, I would scrap that 1/2/Both switch and use an ACR as you mentioned above. I would also direct all your charging sources to your house bank. This way there is no switching. When there is a charge source and the voltage rises to a certain level, the ACR combines the two banks and they are both charged. Typically, this would keep the start battery topped up while it charges the house. Also, if I am correct, this will provide the power to the start batteries that are driving the windlass from the alternator via the ACR.

Anyway, listen to those that know better than I but I think you are on the right track.
Click to expand...

:thumb: Yep! I agree with this :) Adding an amp hour monitor to keep track of how deeply your house bank is discharged would round out your system.
 
If you make your own battery box you my gain some space. I did my own box for 4 gc2 and it is taking less space than 4 gc2 boxes.

L
 
Easting said:
.. The ACR just charges the house bank 1st and then moves to the start bank when the house is charged. No need to touch the combiner switch.
Maybe someone else can add something here?
Click to expand...
Why not charge the start batt first, then the house batts. The ability to move the boat under its own power seems the priority. It doesn`t take much to recharge after a start.
 
BruceK said:
Why not charge the start batt first, then the house batts. The ability to move the boat under its own power seems the priority. It doesn`t take much to recharge after a start.
Click to expand...

This is my thinking. I think I would rather my start bank be charged first. Right now I have my starb 45 amp alt. charging my start battery and my port 65 amp alt charging my house bank which includes my windlass. I can combine with switches but this is how I run for now. My generator has it's own battery. So far so good although my 4D's are getting old so I may be switching to GC bats soon for the house keeping a 4D to start both my Perkins 4-236s. Man there are so many combos it's dizzying!

Kevin
 
BruceK said:
Why not charge the start batt first, then the house batts. The ability to move the boat under its own power seems the priority. It doesn`t take much to recharge after a start.
Click to expand...


Precisely why the primary battery should be the largest and the one that discharges the deepest. It should be fed directly (fused) from the alternator and the regulator sense lead (if externally regulated) should monitor the largest bank. Otherwise it's working backwards. What advantage is there to having the alternator regulate its voltage based on the battery that has the the quickest charge rate? In doing so, the alternator sees a higher voltage, and reduces output faster. The battery relay is in use far more than it needs to be, and if it fails, the largest power consumer is SOL.
 
Maerin’s point is a good one. One other disadvantage to an ACR is that both banks are then being charged by the same charge profile. Not a problem if they are the same type of battery, but not optimal if the batteries are different.

That is one reason I like the Balmar Duo-charger, it has some very basic settings for the type of battery it is charging. I also use an Echo-charger for my start battery. When the house battery is reaches 13v the Echo charger starts to feed the start battery at a max of 15 amps. It feeds the start battery at whatever voltage the house bank is at. So in this way it is different than the Duo-charger.

Anyway, whether you use a simple DC to DC charger like the two above, or you use an automatic combining relay which turn the two banks into a single bank while they are being charged, they all depend on feeding the charge sources to the house bank. The starter battery will get fully charged .
 
"It should be fed directly (fused) from the alternator and the regulator sense lead (if externally regulated) should monitor the largest bank"

A fuse in an alt output is a big danger.

It might help in a short to not have a fire BUT anytime the working alt is disconnected from a load , it will usually blow the output diodes.

These are not expensive but a PIA to swop out underway.
 
4mo said:
I only have one alternator so my procedure would be to wake up in the morning, check the batteries, make coffee (press) and when its time to pull the anchor i would switch it from the house bank to the start bank, start the motors, pull anchor, then switch it to house bank while i'm under way to charge up the house bank with the alternator.
Click to expand...


I'd have guessed a Carver 370 Voyager would have twin engines? Two alternators?

-Chris
 
You're right on the alternators, not sure why I thought there was only one. I'll see how they are wired today.
 
FF said:
"It should be fed directly (fused) from the alternator and the regulator sense lead (if externally regulated) should monitor the largest bank"

A fuse in an alt output is a big danger.

It might help in a short to not have a fire BUT anytime the working alt is disconnected from a load , it will usually blow the output diodes.

These are not expensive but a PIA to swop out underway.
Click to expand...


Mr. FF makes a great point, one I overlooked. The case could be made that the alternator is self-limiting, so a fuse isn't really necessary. That doesn't alter the fact that the feed wire from the alternator should probably be fused at the battery/buss connection point to protect the wire in the event of a short. The answer there would be a fuse that would protect the conductor in the event of a dead short, but not have the potential for a nuisance trip- perhaps twice the amp output of the alternator. In that scenario a diode failure might be acceptable collateral damage.


If the alternator feed wire is replaced, it makes sense to go big on that conductor. Perhaps more capacity in the future, insuring no voltage drop. Cost difference would be minimal with no impact on labor.
 
Maerin said:
Mr. FF makes a great point, one I overlooked. The case could be made that the alternator is self-limiting, so a fuse isn't really necessary. That doesn't alter the fact that the feed wire from the alternator should probably be fused at the battery/buss connection point to protect the wire in the event of a short. The answer there would be a fuse that would protect the conductor in the event of a dead short, but not have the potential for a nuisance trip- perhaps twice the amp output of the alternator. In that scenario a diode failure might be acceptable collateral damage.


If the alternator feed wire is replaced, it makes sense to go big on that conductor. Perhaps more capacity in the future, insuring no voltage drop. Cost difference would be minimal with no impact on labor.
Click to expand...

Bingo! :thumb:

The fuse protects from a short on the alternator wire, e.g. the wire falls off the alternator and shorts on the engine. My large cable from the alternator to the battery can carry lots of juice and the fuse protects from a possible electrical fire. If the fuse fails and causes the diode to blow, then that can be repaired.

I'd rather repair an alternator than fight a fire.
 
4mo said:
Even though i can always start the generator and then start the mains? that does take a while, which could be an issue if i'm dragging or something. Any other reason?
Click to expand...

That isn't reason enough?
 
I read most posts... lotsa good - batt ways. Here's my 5 cents!

House Bank = 4 g31 deep cycle wet la batts in parallel [they also start my twins] - charged by 60 amp professional mariner [gen set or shore power], and, starboard engine.

1 g24 starter wet la batt for gen set, forward head and windlass - charged by solar trickle, and, 1.25 amp trickle charger off 120 v from gen set or shore power.

1 isolated g24 starter wet la batt for any emergency that may happen - charged by 1.25 amp trickle charger off 120 v from gen set or shore power.

House Bank 31's just reached 9 years - they're still kicking... but run down too soon now. Planning to put in 4 new ones quite soon.

Gen set / front head / windless g24 batt 2 yrs. old. Isolated emergency g24 batt 1.5 yrs old.

Also have a g24 starter batt in tow behind runabout... it's about 1 yr .old.

All batts are from Batteries Plus; they're made by East Penn. Good service good prices.

Note: I've found that dual purpose [starter/deep cycle] batts wear out way too quickly.
 
Last edited:
Easting said:
“ only have one alternator so my procedure would be to wake up in the morning, check the batteries, make coffee (press) and when its time to pull the anchor i would switch it from the house bank to the start bank, start the motors, pull anchor, then switch it to house bank while i'm under way to charge up the house bank with the alternator. “

Even more simple......

Keeping the start bank and the house bank separate and having an ACR would do this for you. (Except making the coffee) :)
Click to expand...

Exactly!! This is the process on 'Slo~Belle' Upon engine start, the ACR switch is made and the start battery is joined with the house battery for charging purpose while underway. On shore power or shutdown, the ACR isolates the start battery. The anchor winch is tied to the start battery for the same . the engine is running while the anchor is being retrieved.
 
Al said:
Exactly!! This is the process on 'Slo~Belle' Upon engine start, the ACR switch is made and the start battery is joined with the house battery for charging purpose while underway. On shore power or shutdown, the ACR isolates the start battery. The anchor winch is tied to the start battery for the same . the engine is running while the anchor is being retrieved.
Click to expand...

While I would have preferred a solution that makes me coffee as well, this certainly sounds the best.

I installed the 4 GC batteries yesterday and got the Victron 700 working (i believe) I kept the 2 group 27 start batteries as dedicated starters/windlass power and will be hooking up an ACR this weekend to combine them for charging.

Thanks all for the helpful ideas, input and patience with a newbie!
 
Easting said:
Not sure one will have anything to do with the other. The ACR just charges the house bank 1st and then moves to the start bank when the house is charged. No need to touch the combiner switch.

Maybe someone else can add something here?
Click to expand...


My understanding is different. From Blueseas website Q&A:

“An ACR senses when the voltage of either of the batteries rises to a level indicating that a charge source is active (13.0V for 2 minutes). The ACR′s contacts then connect and the ACR applies the charge to both batteries. If the voltage on both of the batteries subsequently drops to 12.75V for 30 seconds, the ACR will disconnect, isolating the batteries.”

https://www.bluesea.com/products/7610/SI-ACR_Automatic_Charging_Relay_-_12_24V_DC_120A/FAQ

So it house bank isn’t charged first, and then the start bank. Only that the batteries are combined when the charge source reaches 13.0 V.

Jim
 
"Even more simple......

Keeping the start bank and the house bank separate and having an ACR would do this for you. "
Simpler yet,(and less costly)

The simplest of all is an RV solenoid , about $17. at the camper store , Plus about $20 for a Cole Hersee start switch with an ACC terminal.

On starting the key operates the starter from the start batt and the ACC terminal is not powered.

This saves anything that might be damaged by a stuck starter , 150V or more is much un-fun for many boat goodies.

The start engine alt is also powered from the ACC terminal so the starting load does not include the alt. attempting to make juice.

After starting the ACC terminal on the key is powered so the start batt is merged with the house bat by the RV relay.

No hassle as the batts with the lowest voltage (usually the house) gets the big charge .
Eventually all will have the same voltage .

On shut down the key removes the power from the ACC terminal so the house system is now isolated from the start.

So simple there is no shut down check list , just like your car.

The price is right and best of all should there be a relay failure its easy to find and a few seconds to bypass.


KISS!
 
Last edited:
Start vs. House Bank

We had a full house bank put in in '16.

It consists of 6-L16 6V AGM batteries. They are wired in series & parallel.

The 2-4D wet cells engine batteries were just replaced at the beginning of this season with 2-4D AGM's.

Charging is handled 2 ways.

We have an SW3012 Xantrex charger/inverter connected to the house bank.

Balmar 125A alternators, on each engine, are connected to Balmar regulators, which are connected to Duo-chargers which are connected to something called a centerfielder.

When we are running the alternators produce power which ultimately finds it's way to the centerfielder. That decides where the power goes, house or engine bank and how much.

When we are on shore power the Xantrex charges the house bank as power is passed thru to the house.

Good or Bad, if we lose shore power the boat instantly switches to battery power. This has happened on a few occasions, we didn't realize we were on battery. I've got to put in a red light, or some way to know, if we switch from shore power to battery.

We also had installed when all this equipment was going in a dual ELCI and Galvanic Isolator.

We find that this setup works very well and while we are on the Loop it provides power for 2-3 days while on a wall or anchoring.

Future plans include investigation of a fuel cell and or solar cells.
 
FF said:
The simplest of all is an RV solenoid , about $17. at the camper store , Plus about $20 for a Cole Hersee start switch with an ACC terminal.
Click to expand...

How does this system protect the system from a battery which shorts out or otherwise dies in service. Seems you could run all day and find all your batteries are similarly drained because there is no low voltage cutout.
 
Nepidae said:
We have an SW3012 Xantrex charger/inverter connected to the house bank.

Balmar 125A alternators, on each engine, are connected to Balmar regulators, which are connected to Duo-chargers which are connected to something called a centerfielder.

When we are running the alternators produce power which ultimately finds it's way to the centerfielder. That decides where the power goes, house or engine bank and how much.

When we are on shore power the Xantrex charges the house bank as power is passed thru to the house.

Good or Bad, if we lose shore power the boat instantly switches to battery power. This has happened on a few occasions, we didn't realize we were on battery. I've got to put in a red light, or some way to know, if we switch from shore power to battery.
Click to expand...


I'm a bit confused by the use of the alternator regulators, Duo-Chargers, and the Centerfielder. Generally, the Duo-charger is connected between the house bank and the start batteries. The regulated alternator usually then feeds the house bank directly. The Centerfielder sounds interesting. I've never heard of it.


Your charger inverter likely has a setting where it will shut off the inverter if the battery voltage drops to given level. That can protect you from draining the battery bank too low with the inverter. What you describe happened to me for the first time a couple weeks ago and I didn't know it until the inverter cut out due to the battery voltage hitting that low-bat cut off.
 
rgano said:
How does this system protect the system from a battery which shorts out or otherwise dies in service. Seems you could run all day and find all your batteries are similarly drained because there is no low voltage cutout.
Click to expand...

I have something similar. A 90 amp continuous duty relay, 150 surge. Activates when port engine ignition turns on, AND I have the manual switch set to on.
When I turn off port engine, OR flip off manual switch, the relay disconnects.
To wire it up, I used a 4 gauge wire, runs from start bank to relay then to house bank. Relay control wire comes from port motor ignition, to manual switch, to combiner relay then to ground.

I have noticed combining when running both alternators share the load. They are 12SI one wire design.

Also doing it this way, you get a boost from the house when you start your engines. Like a jump start, so less wear on the start bank. Just start port engine first, or turn on it's ignition, then start the starboard engine.

With the manual switch, you can force a disconnect to the system.

These relays are real cheap on Amazon. 150 amp continuous, 300 amp surge!

https://www.amazon.com/CONTINUOUS-S...0BGTL9GI/ref=cm_cr_arp_d_product_sims?ie=UTF8
 
Last edited:
You must log in or register to reply here.

Similar threads

L
Prosport 20 not charging
Replies
8
Views
368
C lectric
C lectric
dhays
Time for new Thruster Bank I'm afraid 😟
Replies
26
Views
2K
Capt Ray
C
R
Hot off-gassing house batteries?
Replies
27
Views
2K
OldDan1943
OldDan1943
Xfirepop
Dead Battery Bank
Replies
26
Views
1K
Lepke
Lepke
X
New Lithium Bank
Replies
1
Views
466
READY
R

Latest posts

Back
Top Bottom