Starter Battery Component Locations

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Stu Jackson

#30
Quote from: mainesail on January 27, 2016, 11:53:26 AMThis is one reason I prefer battery switches closer to the bank, as does the ABYC...

This is very good advice.

IF I was completely rebuilding the entire electrical system, I might, just might, consider it.

OTOH, what I suggest you do, before you move the 1-2-B switch from the panel, is to consider the DIFFERENCES in the lengths of the load feeders between that OEM location and ANY OTHER you might find.

Since we've had almost 30 years of experience with our boats, and there are only so many places we have learned that things will actually FIT on our boats, the six feet of wire (three across, three up) from the battery compartment to the OEM switch location is not really that long, and I'd be willing to bet that any other location for the switch, EXCEPT for right on the wall of the battery compartment, would not decrease that length all that much.  And besides, even if you moved the switch to that location, you are still faced with running the wires FROM the switch TO the distribution panel and the starter, right?

The ONLY way I can see to follow the guidance offered by Maine Sail, on a Catalina 34, is to move the distribution panel closer to the battery box.  That simply ain't gonna happen.

Please understand, we've BTDT.  The whole purpose of this entire website is to avoid having skippers reinvent the wheel.

We've provided three or four different ways to switch the main wiring from battery banks to the starter and distribution panel.  We've shown and recorded, from various skippers, any number of different places to place more batteries in addition to the OEM central battery compartment in front of the galley sink.

If you can find some more, we're all ears!   :clap :clap :clap 

I'd place first your efforts right now on an understanding of the concepts between the different switching possibilities, sizing the wiring (as Jon has been doing), finding the right switch location(s) that suit your understanding (like Noah did), and designing your system, before you do anything physical on the boat.

Good luck, we're here to help.
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

mainesail

#31
Stu,

Unfortunately there is not much we can often do about the poor battery switch location chosen by Catalina. In terms of voltage transients the closer the take off point for the DC loads to the physical battery bank the less risk we have of seeing damaging transients. Sadly boats are a compromise and we do the best we can. Lots of builders, inclduing Catalina, Ericson & others used the DC panel for switches and this very often results in more wire than is necessary and more risk of chafe and shorting. Part of the reason for my 1/2/BOTH write up is to help owners with situations like this. It is often quoted as "Maine Sail's preferred method" but really its not its just "a method" to work with what we have. Unfortunately we do not always have the luxury of starting from scratch.

With the switch halfway between the starter and bank the risk increases but damaging spikes are still rare if the boat is wired well otherwise..

That said the biggest occurrence I see of electronics blown via transients is though lightning or when an owner passes a battery switch through OFF with the motor running. Sometimes it is just the diodes that go but the alt path is still directly connected to the loads path at the "C" post and despite not being connected to the battery the loads are still connected to an open circuited and spiking alternator.

When this happens the voltage transient can take out electronics too not just the alt diodes. An owner may have started his bank 1000 times via the 1/2/BOTH and never blown electronics but the minute he/she passes through OFF, and the alt takes out electronics, the transient is almost always blamed on the starter motor, instead of the most likely cause, which is open circuiting an operational alternator..

No one in the industry really talks about this but I surmise it is the probably the number 1 killer of instruments in terms of on-board caused voltage transients. We can avoid this type of transient quite easily by direct wiring the alternator to the house bank..
-Maine Sail
Casco Bay, ME
Boat - CS-36T

https://marinehowto.com/

Noah

#32
http://c34.org/bbs/index.php?action=dlattach;topic=3044.0;attach=4689;o

http://c34.org/bbs/index.php?action=dlattach;topic=8790.0;attach=5486;image

The three switches shown include my on/off switch for my house bank. The two switches shown in the aft cabin are my start battery on/of switch. The second one is my emergency combiner switch to hook both banks together if I need to. That switch has a removable key handle  I keep it in the chart table until I ever need it. Stops people from accidentallyflipping it!

The third switch in the main saloon on the outside of the battery box/settee is the on/off for my house bank. I only have breakers and meters/ monitors on my main
1990 hull #1014, San Diego, CA,  Fin Keel,
Standard Rig

mark_53

Quote from: mainesail on January 27, 2016, 11:53:26 AM

The SI wire is not really a sensing wire it disables or opens the ACR the second you hit the start button.


I'm trying to locate where to hookup the SI wire.  I need to connect the SI sensor to a 12V circuit that is activated when the start button is pressed.  My start button has black wires coming out out both terminals on the backside.  Does this mean the switch is from the negative side?  Maybe the is a more convenient place to attach the SI wire on the starter solenoid?

J_Sail

Noah's approach of using a separate On/Off switch for each battery (each right near their battery) and a simple On/Off switch for emergency-combining results in a much simpler/cleaner system in the end. It avoids potential confusion in an emergency related to the more complicated topology of repurposing the 1-2-both factory switch and provides for nice short wire runs, with key loads being connected close to the battery as MaineSail recommends for reliable operation of your electronics at all times. 

The drawback is that it requires more upfront re-wiring to get rid of the factory 1-2-both switch at the panel.

The benefit of the rewire work, though, is that you can use proper heavy-gauge marine wire where needed and create shorter runs that don't have to snake their way to the main panel and back. When done properly you end up with a system that is robust, flexible, and much simpler to understand.  Simplicity can save your ass when you are stuck somewhere, frustrated, cold and wet, and are can't find the damn diagram that says which switch positions to use to get your radio working from your reserve/start battery while keeping your shorted/dead big house bank from draining that critical but smaller reserve battery.

Separately, after looking carefully at the ACR vs EchoCombiner trade-offs, I now favor the EchoCharger, particularly for C34's where you likely need to charge a single reserve/start battery (often AGM) and have a larger flooded house bank. For example, your shore power charger may be set to occasionally do an "equalize" cycle on the house bank, something you would not want to subject the reserve battery to. There are other reasons as well, and although the BlueSea ACR is a great product, in the end I think the trade-offs favor the EchoCharge for this application.

mark_53

#35
Quote from: J_Sail on February 13, 2016, 10:19:21 AM
Noah's approach of using a separate On/Off switch for each battery (each right near their battery) and a simple On/Off switch for emergency-combining results in a much simpler/cleaner system in the end. It avoids potential confusion in an emergency related to the more complicated topology of repurposing the 1-2-both factory switch and provides for nice short wire runs, with key loads being connected close to the battery as MaineSail recommends for reliable operation of your electronics at all times. 

The drawback is that it requires more upfront re-wiring to get rid of the factory 1-2-both switch at the panel.

The benefit of the rewire work, though, is that you can use proper heavy-gauge marine wire where needed and create shorter runs that don't have to snake their way to the main panel and back. When done properly you end up with a system that is robust, flexible, and much simpler to understand.  Simplicity can save your ass when you are stuck somewhere, frustrated, cold and wet, and are can't find the damn diagram that says which switch positions to use to get your radio working from your reserve/start battery while keeping your shorted/dead big house bank from draining that critical but smaller reserve battery.

Separately, after looking carefully at the ACR vs EchoCombiner trade-offs, I now favor the EchoCharger, particularly for C34's where you likely need to charge a single reserve/start battery (often AGM) and have a larger flooded house bank. For example, your shore power charger may be set to occasionally do an "equalize" cycle on the house bank, something you would not want to subject the reserve battery to. There are other reasons as well, and although the BlueSea ACR is a great product, in the end I think the trade-offs favor the EchoCharge for this application.

I'd have agree with you that separate on/off switches would be more robust and simpler to operate, but that seems like much more rework then
re-purposing the 1-2-B switch.

As far as the EchoCharger vs ACR, using mixed battery types was not an issue to me since a FLA battery was low cost and suited my purpose, which was an isolated dedicated start/reserve battery.  The ACR could also fit in the house battery box.  The EchCharger seemed larger and I was looking for a concealed solution.

mark_53

I thought I would follow-up and post the final configuration of my start battery upgrade. The schematic may be useful for those who want a dedicated isolated start battery to protect their sensitive electronics but chose not to upgrade to a high output alternator at this time.  Below is a simplified schematic of the system wiring. The LED on the engine panel indicates ACR is functioning properly before I lose charge.  Also as an indicator if I left the start battery switch on and closed the thru hull before leaving the boat.

Locations I chose for the system components are listed below.

ACR - Aft wall of existing Battery Box
Start Battery on/off switch - starboard wall under head sink
Start Battery - In new battery box mounted behind prop shaft in aft cabin.
House Batteries - In existing battery box
1-2-Both Switch - In existing location on DC Panel.
Battery Charger - In existing location under Nav Table



Thanks to all who helped with their comments.