Battery charger always on?

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I agree. This setup is a scheme that used to be pretty popular. Two main banks. The idea being, when you reach anchorage, you select one bank to use to power the house loads. This leaves one bank untouched for starting up the engine the next day. You would alternate which bank to use so they wear evenly.
If this is the scheme going forward, two separate battery monitors are needed. One for each main bank.
The other option is, get a separate battery for starting the engine and combine the two existing main banks for house loads. Then one monitor is needed.
I would take a little time and think about this if I were you.
Two questions here:

1. the dotted purple line (1) was not provided with the monitor. is it supposed to be at least the same gauge as the existing line (3)?

2. should the dashed orange line (2) be wired to the pos terminal of a random/nearest battery in the bank, or to the pos buss bar on the left end of the below figure?

Screenshot 2024-06-12 212735.png
 
@ranger58sb
@Bmarler
You would be correct if the positive from each bank is not connected. Subject to the OP correction, I understand that this is one bank separated due to space restrictions.
there is a batt selector that can be set to 1, 2, Both and Off. it is my understanding "Both" will connect the positives of the two banks. I haven't managed to see the exact wiring at the selector, it's located at the lower corner of helm station with difficult access
 
there is a batt selector that can be set to 1, 2, Both and Off. it is my understanding "Both" will connect the positives of the two banks. I haven't managed to see the exact wiring at the selector, it's located at the lower corner of helm station with difficult access
Then my suggestion stands if you charge both banks with the same charger(s) and have only one shunt, one monitor. You select 1 or 2 or both flow will be measured.
If you do not connect the two negative to the one shunt then when that 1 or 2 does not go through shunt the monitor will just display the 1 or 2 that is connected.
 
Thanks. Here is my understanding, please correct if I'm wrong. To combine the two banks is relatively easier. Dialing the batt selector to "Both" will do. To be able to use just one batt monitor would require wiring all 6 Northstar batteries in parallel, so that one monitor can be placed before all loads and chargers.

The engine starter is wired to the ignition switches in both the lower helm and fly bridge. I haven't explored the wiring in either area yet. I can see this may be doable just by rewiring, but would think about it later and keep the current layout for now.
Yes, I think you have a good understanding of how it’s wired. In addition to routing power to the house loads, the battery selector switch also routes it to the starter.
Many things would need to change in order to use one monitor. It is simply a matter of re wiring some things, but should be done in a thoughtful manner.
 
Then my suggestion stands if you charge both banks with the same charger(s) and have only one shunt, one monitor. You select 1 or 2 or both flow will be measured.
If you do not connect the two negative to the one shunt then when that 1 or 2 does not go through shunt the monitor will just display the 1 or 2 that is connected.
Functional, maybe. Practical, no. It’s not really a good idea to use one shunt for multiple banks. The amp hour counting depends on measuring in and out, and some are “smart” and learn over time.
It’s a fairly simple thing to wire the banks together, but I would be redesigning the layout and make the cabling simpler and shorter.
In this case, two monitors is a pretty good idea, at least until a new house bank strategy is implemented.
 
Functional, maybe. Practical, no. It’s not really a good idea to use one shunt for multiple banks. The amp hour counting depends on measuring in and out, and some are “smart” and learn over time.
It’s a fairly simple thing to wire the banks together, but I would be redesigning the layout and make the cabling simpler and shorter.
In this case, two monitors is a pretty good idea, at least until a new house bank strategy is implemented.
I intend to leave the rewiring for later on, after the ongoing projects
could you comment on post #151?
 
I just got time last night to check the dc wiring. there are still more wires than I was able to trace, here is what I noted:

the batteries include 6 Northstar NSBG31 batteries (2 banks) and 1 Odyssey Extreme 2150 battery :

bank 1 (port side) has 3 batteries (#1-3 parallel)
bank 2 (starboard side) has 3 batteries (#1-3 parallel)
1 Odyssey Extreme battery next to the engine's port side, wired only to the gen starter

each side has a dc distribution panel. The battery charger has 3 pos wires outgoing to dc panels on both sides and the Odyssey battery. The battery charger is going through the bulkhead to the elec box behind the main dist panel.

main loads on port side panel: two thrusters, xantrex xm1800 inverter, fuel transfer pump
main loads on starboard side panel: charles inverter for fridge, raritan electra scan msd, priming fuel pump for racors

The engine starter seems to take power from the main electrical box via two thick cables

I think it'd be better to put separate a shunt/monitor on each main bank. That would give the ability to view each battery bank level in relation to its specific loads.

-Chris

I agree. This setup is a scheme that used to be pretty popular. Two main banks. The idea being, when you reach anchorage, you select one bank to use to power the house loads. This leaves one bank untouched for starting up the engine the next day. You would alternate which bank to use so they wear evenly.
If this is the scheme going forward, two separate battery monitors are needed. One for each main bank.
The other option is, get a separate battery for starting the engine and combine the two existing main banks for house loads. Then one monitor is needed.
I would take a little time and think about this if I were you.

Thanks. Here is my understanding, please correct if I'm wrong. To combine the two banks is relatively easier. Dialing the batt selector to "Both" will do. To be able to use just one batt monitor would require wiring all 6 Northstar batteries in parallel, so that one monitor can be placed before all loads and chargers.

The engine starter is wired to the ignition switches in both the lower helm and fly bridge. I haven't explored the wiring in either area yet. I can see this may be doable just by rewiring, but would think about it later and keep the current layout for now.

OK, I went back through the thread, to sort of "review the bidding"... and I see this is the one that started with a worry about potential overcharging... and then morphed to something about monitoring something somewhere on or around post #81...

But there's the post describing loads on each main bank -- inverter on each, MSD on one, thrusters, fuel pumps -- and I'd imagine there are probably some lighting circuits (nav, anchor, deck lighting, interior lighting), nav electronics. One inverter feed a fridge, the other ....?? Maybe AC outlets for things like laptops, toasters, coffee makers, icemaker, microwave/convection oven, tuner/stereo amp, TV? IOW, the loads are separated...

And near as I can guess, since the main loads are separate, the "two banks" thing is NOT to swap between one and the other at anchor. (In which case, all loads would transfer? Some guessing, there.... ) Instead, I'd guess that architecture was specifically to spread the DC loads (and inverter AC loads), and maybe the only reason for a combiner switch is if the user over-achieved drawing down one bank or the other... so the switch can act as a temporary safety net... until the real fix (recharging) can happen.

If that's anywhere close at all, I doubt I'd spend much time worrying about changing battery architecture. Instead, I'd just (over time) beef up each battery bank to the extent necessary/possible (that extra battery box for each might be applicable), put a monitor on each bank, call it good, and move on to a real problem.

3x G31s on each bank is probably ~300 Ah nominal capacity, ~600 Ah total. Adding a fourth to each bank would make it ~400 Ah each bank, ~800 Ah total. What's not to like? The cost of a second monitor is basically squat, in the grans scheme of things.

(Some of this is guided by experience with battery architecture of our previous two boats and this current boat. All had/have two main banks; each starting an engine and each servicing about half of the DC house loads. Only one had a 1-2-All switch, and it was the boat with only 3x batteries total, 1x on one bank, 2x on the other (fridge) bank, not much room for additional batteries. The DC panels were/are separated for basic load management, not for swapping out which bank happens to be servicing a whole house at any given time. No way to do that on the last two boats without 1-2-All switches. Instead, that's what starting a generator solves.)

Bottom (sorta) line: the current architecture is workable, and a (completely discretionary) monitor on each bank could be a good thing, physically rewiring the two banks into one larger bank would buy not a lot -- at significant expense expressed in either time, money, or both.

It is, of course, highly possible that I don't know what I don't know relative to OPs situation, goals, etc. :)

-Chris
 
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Two questions here:

1. the dotted purple line (1) was not provided with the monitor. is it supposed to be at least the same gauge as the existing line (3)?

2. should the dashed orange line (2) be wired to the pos terminal of a random/nearest battery in the bank, or to the pos buss bar on the left end of the below figure?

View attachment 155562
Missed seeing this post earlier, sorry.
Anyway, the purple line (wire 1),needs to be as big or bigger than the existing wire 3. If it’s close to the batteries, I would just make it up out of 4/0.
I would wire the 2 wire to the battery post. You’ll get the most accurate volt reading there.
 
OK, I went back through the thread, to sort of "review the bidding"... and I see this is the one that started with a worry about potential overcharging... and then morphed to something about monitoring something somewhere on or around post #81...

But there's the post describing loads on each main bank -- inverter on each, MSD on one, thrusters, fuel pumps -- and I'd imagine there are probably some lighting circuits (nav, anchor, deck lighting, interior lighting), nav electronics. One inverter feed a fridge, the other ....?? Maybe AC outlets for things like laptops, toasters, coffee makers, icemaker, microwave/convection oven, tuner/stereo amp, TV? IOW, the loads are separated...

And near as I can guess, since the main loads are separate, the "two banks" thing is NOT to swap between one and the other at anchor. (In which case, all loads would transfer? Some guessing, there.... ) Instead, I'd guess that architecture was specifically to spread the DC loads (and inverter AC loads), and maybe the only reason for a combiner switch is if the user over-achieved drawing down one bank or the other... so the switch can act as a temporary safety net... until the real fix (recharging) can happen.

If that's anywhere close at all, I doubt I'd spend much time worrying about changing battery architecture. Instead, I'd just (over time) beef up each battery bank to the extent necessary/possible (that extra battery box for each might be applicable), put a monitor on each bank, call it good, and move on to a real problem.

3x G31s on each bank is probably ~300 Ah nominal capacity, ~600 Ah total. Adding a fourth to each bank would make it ~400 Ah each bank, ~800 Ah total. What's not to like? The cost of a second monitor is basically squat, in the grans scheme of things.

(Some of this is guided by experience with battery architecture of our previous two boats and this current boat. All had/have two main banks; each starting an engine and each servicing about half of the DC house loads. Only one had a 1-2-All switch, and it was the boat with only 3x batteries total, 1x on one bank, 2x on the other (fridge) bank, not much room for additional batteries. The DC panels were/are separated for basic load management, not for swapping out which bank happens to be servicing a whole house at any given time. No way to do that on the last two boats without 1-2-All switches. Instead, that's what starting a generator solves.)

Bottom (sorta) line: the current architecture is workable, and a (completely discretionary) monitor on each bank could be a good thing, physically rewiring the two banks into one larger bank would buy not a lot -- at significant expense expressed in either time, money, or both.

It is, of course, highly possible that I don't know what I don't know relative to OPs situation, goals, etc. :)

-Chris
Thanks for reviewing the lengthy thread and understanding those boring questions.

my guess is the batt switch only governs the main dc panel. it will not completely isolate either bank ... lighting circuits (nav, anchor, deck lighting, interior lighting), nav electronics -- these are wired from the main dc dist panel that is controlled by the batt switch. e.g. turning the switch to Off, all dc lights are off.

the two inverters, and all devices connected directly to each bank, rather than wired from the main dc dist panel, will remain powered. They will not be affected by the batt switch
 
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Missed seeing this post earlier, sorry.
Anyway, the purple line (wire 1),needs to be as big or bigger than the existing wire 3. If it’s close to the batteries, I would just make it up out of 4/0.
I would wire the 2 wire to the battery post. You’ll get the most accurate volt reading there.
Thanks.

now if I want to add the gen starting batt to the port side batt monitor, by adding two wires -- a and b below, according to the user instruction. wire a) comes with the monitor (18awg). I believe wire b) can use the same gauge as wire a.

Is the wiring of a and b correct for including the gen starting batt to the port side total soc?

Screenshot 2024-06-14 204816.png




Image_20240614205304.jpg
 
Thanks for reviewing the lengthy thread and understanding those boring questions.

my guess is the batt switch only governs the main dc panel. it will not completely isolate either bank ... lighting circuits (nav, anchor, deck lighting, interior lighting), nav electronics -- these are wired from the main dc dist panel that is controlled by the batt switch. e.g. turning the switch to Off, all dc lights are off.

the two inverters, and all devices connected directly to each bank, rather than wired from the main dc dist panel, will remain powered. They will not be affected by the batt switch

???

I thought I saw earlier you said each battery bank went to it's own panel. I didn't see (notice?) mention of a "main" DC panel.

Does that mean you have a main DC panel and two DC sub-panels?

What's the main panel look like? Two rows of DC load breakers? If so, is there a bank breaker to energize each row? Or does that 1-2-All battery switch energize one row on 1, the other row on 2, both rows on All?

-Chris
 
???

I thought I saw earlier you said each battery bank went to it's own panel. I didn't see (notice?) mention of a "main" DC panel.

Does that mean you have a main DC panel and two DC sub-panels?

What's the main panel look like? Two rows of DC load breakers? If so, is there a bank breaker to energize each row? Or does that 1-2-All battery switch energize one row on 1, the other row on 2, both rows on All?

-Chris
Yes, there two dc panels in the bilge each directly connected to a bank. The main dc panel is at the lower helm. The batt selector is at lower right corner in the photo

IMG20240615095123.jpg


Batt selector seen from the elec box behind the main dist panel:
IMG_20240615_095629.jpg

A little bit challenging to trace wires under this bottom up approach. I haven't attempted to figure out all the wiring here. Turning selector to Off essentially shut off all dc breakers.
 
OK, I went back through the thread, to sort of "review the bidding"... and I see this is the one that started with a worry about potential overcharging... and then morphed to something about monitoring something somewhere on or around post #81...

But there's the post describing loads on each main bank -- inverter on each, MSD on one, thrusters, fuel pumps -- and I'd imagine there are probably some lighting circuits (nav, anchor, deck lighting, interior lighting), nav electronics. One inverter feed a fridge, the other ....?? Maybe AC outlets for things like laptops, toasters, coffee makers, icemaker, microwave/convection oven, tuner/stereo amp, TV? IOW, the loads are separated...

And near as I can guess, since the main loads are separate, the "two banks" thing is NOT to swap between one and the other at anchor. (In which case, all loads would transfer? Some guessing, there.... ) Instead, I'd guess that architecture was specifically to spread the DC loads (and inverter AC loads), and maybe the only reason for a combiner switch is if the user over-achieved drawing down one bank or the other... so the switch can act as a temporary safety net... until the real fix (recharging) can happen.

If that's anywhere close at all, I doubt I'd spend much time worrying about changing battery architecture. Instead, I'd just (over time) beef up each battery bank to the extent necessary/possible (that extra battery box for each might be applicable), put a monitor on each bank, call it good, and move on to a real problem.

3x G31s on each bank is probably ~300 Ah nominal capacity, ~600 Ah total. Adding a fourth to each bank would make it ~400 Ah each bank, ~800 Ah total. What's not to like? The cost of a second monitor is basically squat, in the grans scheme of things.

(Some of this is guided by experience with battery architecture of our previous two boats and this current boat. All had/have two main banks; each starting an engine and each servicing about half of the DC house loads. Only one had a 1-2-All switch, and it was the boat with only 3x batteries total, 1x on one bank, 2x on the other (fridge) bank, not much room for additional batteries. The DC panels were/are separated for basic load management, not for swapping out which bank happens to be servicing a whole house at any given time. No way to do that on the last two boats without 1-2-All switches. Instead, that's what starting a generator solves.)

Bottom (sorta) line: the current architecture is workable, and a (completely discretionary) monitor on each bank could be a good thing, physically rewiring the two banks into one larger bank would buy not a lot -- at significant expense expressed in either time, money, or both.

It is, of course, highly possible that I don't know what I don't know relative to OPs situation, goals, etc. :)

-Chris
Sorry this post might be a little fragmented, I wrote some of it last night after a cocktail or two…
Pretty sure his architecture has been an evolution over time. The main loads off the two busses started out as things that run when the engine is on. The inverters added later.
The distribution panel is what is powered off the 1-2-both switch. So, the usual house loads except for refrigeration.
I believe that the two panels in the engine room are really the buss bars. The big loads are taken off there, and there’s a cable to the 1/2/all switch on each buss bar.
There may be some minor loads connected to the buss bars as well using individual fuses.
 
Thanks.

now if I want to add the gen starting batt to the port side batt monitor, by adding two wires -- a and b below, according to the user instruction. wire a) comes with the monitor (18awg). I believe wire b) can use the same gauge as wire a.

Is the wiring of a and b correct for including the gen starting batt to the port side total soc?

View attachment 155614



View attachment 155615
That’s the correct wiring. You will only get a volt reading from the aux input. It will be completely separated from the meters amp hour/soc measurement. Still, it’s a good thing to have. That battery just site there with no loads on it, so a fairly accurate state of charge can be had by looking at the resting voltage. Resting voltage is after the battery is unused for 24 hours.
 
That’s the correct wiring. You will only get a volt reading from the aux input. It will be completely separated from the meters amp hour/soc measurement. Still, it’s a good thing to have. That battery just site there with no loads on it, so a fairly accurate state of charge can be had by looking at the resting voltage. Resting voltage is after the battery is unused for 24 hours.
Thanks for the confirmation.
 
Yes, there two dc panels in the bilge each directly connected to a bank. The main dc panel is at the lower helm. The batt selector is at lower right corner in the photo

Given that there's a single pair of meters with a 1-2 battery selector test switch...

I'd say it looks like the whole left side of the main panel runs on one of the main battery banks (1?) and the other whole side of the main panel runs on the other main battery bank (2?).

If so, that should mean load management already sorta happens simply because of that separation architecture.

If so... back to my premise that it's easy enough and generally efficient to keep the banks separate, maybe adding a battery to each bank (in the Batt 4 boxes) to increase capacity if you need it, and then if you want meters install two, one on each bank. Voila!

-Chris
 
I agree. This setup is a scheme that used to be pretty popular. Two main banks. The idea being, when you reach anchorage, you select one bank to use to power the house loads. This leaves one bank untouched for starting up the engine the next day. You would alternate which bank to use so they wear evenly.
If this is the scheme going forward, two separate battery monitors are needed. One for each main bank.
The other option is, get a separate battery for starting the engine and combine the two existing main banks for house loads. Then one monitor is needed.
I would take a little time and think about this if I were you.
anther question, is it necessary to open the dc circuit before adding a ring terminal to the dc panel? if so, does this mean to disconnect the neg cable that is wired from the buss bar shown here to the battery bank?

Image_20240612091334.jpg
 
Given that there's a single pair of meters with a 1-2 battery selector test switch...

I'd say it looks like the whole left side of the main panel runs on one of the main battery banks (1?) and the other whole side of the main panel runs on the other main battery bank (2?).

If so, that should mean load management already sorta happens simply because of that separation architecture.

If so... back to my premise that it's easy enough and generally efficient to keep the banks separate, maybe adding a battery to each bank (in the Batt 4 boxes) to increase capacity if you need it, and then if you want meters install two, one on each bank. Voila!

-Chris
i think both sides of the main panel is run by either bank or both. bilge pump breaker is on the left side, sump pump (forward bilge pump) is on the right side, with the batt selector on 1, sump pump is still powered. with the batt selector to Off, both pumps are offline.
 
i think both sides of the main panel is run by either bank or both. bilge pump breaker is on the left side, sump pump (forward bilge pump) is on the right side, with the batt selector on 1, sump pump is still powered. with the batt selector to Off, both pumps are offline.

I don't see how that particular test would prove it, but maybe I'm not understanding. Should be easy to check, anyway. Put battery selector on 1, see what works. Put battery selector on 2, see what works.

If everything (both sides) works on both tests, yep, you're right. Although at that point I might begin to wonder if some morphing caused by prior owners might have happened...

-Chris
 
anther question, is it necessary to open the dc circuit before adding a ring terminal to the dc panel? if so, does this mean to disconnect the neg cable that is wired from the buss bar shown here to the battery bank?

View attachment 155637
It’s always best practice to de-energize the circuit before working on it.
That said, I don’t always do it. I weigh to possibility of making a short by accident.
If you’re adding a cable to the positive buss pictured, I might just add it to an open terminal without de-energizing it. (Unless there’s something on the terminal already that’s producing or consuming power.) After all, there should be a fuse close to the end of the wire you’re adding. Just leave the fuse out till everything is hooked up.
 
I'm getting stuck at the cable from the batt neg to the batt minus. There is a spare neg cable to use but the connector stud is too small on both ends to fit either. For comparison I placed a ring terminal with 3/8" stud on top. 3/8" or m10, is the correct size.

How to enlarge the hole? I tried guiding a drill bit around the hole inside but saw no effect. I have a dremel, but don't know the material is the connector, or what bit to use.

IMG20240707214257.jpg
 
I just drill through the hole with a 3/8" bit. I can advise to use channel locks or crescent wrench or vice grips to hold the lug when you drill as the bit will grab and torque the lug. Good also to have a wood block under for when the bit goes through
 
The ends are tin plated copper. Very soft, and will grab a drill bit without warning. I have drilled them out before, many times, but as mentioned, use a tool to hold it and a wood block underneath.
If you have a carbide burr for the dremel , that works well too.
 
The ends are tin plated copper. Very soft, and will grab a drill bit without warning. I have drilled them out before, many times, but as mentioned, use a tool to hold it and a wood block underneath.
If you have a carbide burr for the dremel , that works well too.
I was able to enlarge the hole using a 3/8" drill. I had to clamp the cable to a portable work bench, drill it in consecutive pulses.

I also tried a burr bit on a dremel. The bit always bumped around against the edge even at the lowest speed. The first bit from right was what I used. Maybe a smaller bit works.

IMG20240820220713.jpg
 
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