Ground for ACR #sabre34MkII


Phil
 

I am planning on installing a Blue Sea ACR (Automatic Charging Relay) on our Sabre 34ii and am looking for a place easy to reach to connect the ground wire. My understanding is that it is not recommended connecting it to the battery's negative terminal post. Would connecting it to the engine with these other three connections be appropriate as shown in the picture? If not what is recommended?


David Lochner
 

The ACR ground does not carry a lot current, it can go to any convenient negative busbar. It only requires a 1 amp fuse. It is necessary for the voltage sense circuit and the LED.


Dave
Second Star
S362 #113
Fair Haven, NY/Lake Ontario

On Mar 21, 2021, at 10:14 PM, Phil via groups.io <pporesky@...> wrote:

I am planning on installing a Blue Sea ACR (Automatic Charging Relay) on our Sabre 34ii and am looking for a place easy to reach to connect the ground wire. My understanding is that it is not recommended connecting it to the battery's negative terminal post. Would connecting it to the engine with these other three connections be appropriate as shown in the picture? If not what is recommended? <Engine Ground2 _1_.jpg>


Terry
 

Ok, I have to ask.....what does an automatic charging relay do that is different from a conventional set up?

Terry


Peter Tollini
 

Terry

Cliff's Notes version -
It separates house and engine banks while discharging, but connects them while charging.  Both automatically are charged by the alternator, but your brother in law can't drain both banks by leaving the stereo and a bunch of lights on all night with a conventional switch on "Both" With an ACR, you'll still have a full starting battery.

On Mon, Mar 22, 2021 at 9:36 AM Terry <webonomist@...> wrote:
Ok, I have to ask.....what does an automatic charging relay do that is different from a conventional set up?

Terry


Phil
 

My goal is to allow my solar panel or alternator to charge both batteries when the battery selector is set to "Off" or "1" or "2" (obviously the alternator only works at 1 or 2).

Today the battery selector needs to be set to "Both" to accomplish the same, which means I run the risk of draining both batteries if neither the solar panel or alternator are providing a charge.

I am an electronics novice so my understanding maybe incorrect.


Phil
 

Hi David,

Are you suggesting I can use the engine connection, or do I need to find a separate busbar. Unfortunately I did not see any busbars easily accessible.


Jim Starkey
 

Since all electrical grounds are tied together and we're talking about an insignificant amount of current, any convenient ground will do.  It's not something to loose sleep over.

On 3/22/2021 10:43 AM, Phil via groups.io wrote:
Hi David,

Are you suggesting I can use the engine connection, or do I need to find a separate busbar. Unfortunately I did not see any busbars easily accessible.
-- 
Jim Starkey


RICHARD GUTHRIE
 

Phil ,
You can ground to the engine block

Rich S402
NYC 
Norwalk CT


-----Original Message-----
From: Phil via groups.io <pporesky@...>
To: SabreSailboat@groups.io
Sent: Mon, Mar 22, 2021 10:43 am
Subject: Re: [SabreSailboat] Ground for ACR #sabre34MkII

Hi David,

Are you suggesting I can use the engine connection, or do I need to find a separate busbar. Unfortunately I did not see any busbars easily accessible.


David Lochner
 

Yes you can ground to the engine block. Best to do that as close to the main ground lug on the engine. Some blocks may have multiple places to ground, Yanmar for one.

Dave

On Mar 22, 2021, at 10:43 AM, Phil via groups.io <pporesky@...> wrote:

Hi David,

Are you suggesting I can use the engine connection, or do I need to find a separate busbar. Unfortunately I did not see any busbars easily accessible.


Harry Keith
 

As others have said, "any ground" is fine.

But, I want to foot stomp the advice you were given in your first post.

I believe fairly strongly that the ONLY thing connected to a battery post is a battery cable.  The rats nest that grows when a battery post gets all those "must be connected to the battery" devices, such as refrigeration, bilge pumps, battery chargers, stereo keep-alive, alternator, ACR leads, battery monitors, etc leads to lots of risk.  Ideal, to me, is a short battery cable from the battery to a big fuse, and then onward.  From the output of the fuse you could run a short lead to a fuse panel for all those "direct to battery loads."  If it's 16" of #6 or #4 wire away from the battery, you aren't losing anything.  The least acceptable (but still OK) option is a second lead to the battery, that goes to the fuse panel.  But I won't allow ANY smaller wires on my battery terminals.

Besides just hating the appearance, I almost lost my Sabre on delivery home after purchase.  It was a tired boat, needing a lot of work.
*  The batteries were serious toast.  I wanted to do a well planned upgrade, so I didn't replace them before delivery home.
*  I took all the batteries home for a final charge the night before departure.
*  I reinstalled them the morning of departure.  I confused the bilge pump wires, and put both the hot and ground on the hot post (to be fair, the "ground" had an in line fuse!)
*  2 hours later, the prop shaft slipped part way out, destroying the dripless seal.
*  My daughter came up and said "dad, there's water down here."  OH CRAP!

It all worked out fine.  But I have a strong aversion to the confusion of numerous wires on the batteries!

Oh, and as a bonus?  A little 6 circuit blade-type fuse panel is infinitely less confusing than 6 in-line fuses!


On Mon, Mar 22, 2021 at 4:25 PM David Lochner via groups.io <davelochner=mac.com@groups.io> wrote:
Yes you can ground to the engine block. Best to do that as close to the main ground lug on the engine. Some blocks may have multiple places to ground, Yanmar for one.

Dave

On Mar 22, 2021, at 10:43 AM, Phil via groups.io <pporesky@...> wrote:

Hi David,

Are you suggesting I can use the engine connection, or do I need to find a separate busbar. Unfortunately I did not see any busbars easily accessible.


David Lochner
 

The maximum number of connections on a battery post is 4. This allows for 1 connection for the parallel battery, 1 to the positive busbar, and 2 for any important sense wires. And the stack has an order, the parallel cable at the bottom, then the main cable and the 2 sense wires. Same order on the negative side, except temp sensors can be added at the top and they don’t count because they are not current carrying.

Over the past few years battery manufacturers have reduced the height of the terminals making it difficult to impossible to add more than 4 connections to a terminal.


Dave
Second Star
S362 #113
Fair Haven, NY/Lake Ontario

On Mar 22, 2021, at 7:04 PM, Harry Keith <sailor11767@...> wrote:

As others have said, "any ground" is fine.

But, I want to foot stomp the advice you were given in your first post.

I believe fairly strongly that the ONLY thing connected to a battery post is a battery cable.  The rats nest that grows when a battery post gets all those "must be connected to the battery" devices, such as refrigeration, bilge pumps, battery chargers, stereo keep-alive, alternator, ACR leads, battery monitors, etc leads to lots of risk.  Ideal, to me, is a short battery cable from the battery to a big fuse, and then onward.  From the output of the fuse you could run a short lead to a fuse panel for all those "direct to battery loads."  If it's 16" of #6 or #4 wire away from the battery, you aren't losing anything.  The least acceptable (but still OK) option is a second lead to the battery, that goes to the fuse panel.  But I won't allow ANY smaller wires on my battery terminals.

Besides just hating the appearance, I almost lost my Sabre on delivery home after purchase.  It was a tired boat, needing a lot of work.
*  The batteries were serious toast.  I wanted to do a well planned upgrade, so I didn't replace them before delivery home.
*  I took all the batteries home for a final charge the night before departure.
*  I reinstalled them the morning of departure.  I confused the bilge pump wires, and put both the hot and ground on the hot post (to be fair, the "ground" had an in line fuse!)
*  2 hours later, the prop shaft slipped part way out, destroying the dripless seal.
*  My daughter came up and said "dad, there's water down here."  OH CRAP!

It all worked out fine.  But I have a strong aversion to the confusion of numerous wires on the batteries!

Oh, and as a bonus?  A little 6 circuit blade-type fuse panel is infinitely less confusing than 6 in-line fuses!


On Mon, Mar 22, 2021 at 4:25 PM David Lochner via groups.io <davelochner=mac.com@groups.io> wrote:
Yes you can ground to the engine block. Best to do that as close to the main ground lug on the engine. Some blocks may have multiple places to ground, Yanmar for one.

Dave

On Mar 22, 2021, at 10:43 AM, Phil via groups.io <pporesky@...> wrote:

Hi David,

Are you suggesting I can use the engine connection, or do I need to find a separate busbar. Unfortunately I did not see any busbars easily accessible.





Terry
 

Thanks folks, I learn so much from this site.

I think an ACR might be overkill for us (I don't have a brother-in-law and would not entrust the boat to anyone else) but I have an older solar panel that I want to install so that raises the question about a regulator to charge two banks of AGM batteries and maybe then an ACR would be useful.

The only issue with older battery switches is that you have to go through "ALL" to get from 1 to 2. I once had a battery dead short on me and I'm sure it drained the other bank when I went to switch over. I notice newer switches alow you to go through "OFF" to switch between the two banks. It was our one and only Coast Guard tow!

Terry


Jim Starkey
 

I'm not convinced that the engine block is a good choice, though the primary electrical ground would be OK.  Copper and lead are good conductors.  Cast iron is not, and anything attached to the block is a good corrosion candidate.  And having the ACR fail to activate due to a lousy or corroded connection is not likely to be noticed until the second bank is found dead.  Either negative battery terminal would be a better choice.

An even better reason not to use a engine block connection is that an ACR works by comparing the voltage on either positive side to ground, activating the relay is the voltage goes about 13.4.  An engine block is not a great conductor and there is certain to be a voltage drop, possibly enough to keep the ACR from activating.

The best choice might be to recognize that the number of things that need an electrical ground is only going to increase and  ground bus bar in a quasi-convenient place would be a smart thing to add.  It would also give your ACR an accurate reference ground.


On 3/22/2021 4:24 PM, David Lochner via groups.io wrote:
Yes you can ground to the engine block. Best to do that as close to the main ground lug on the engine. Some blocks may have multiple places to ground, Yanmar for one.

Dave

On Mar 22, 2021, at 10:43 AM, Phil via groups.io <pporesky@...> wrote:

Hi David,

Are you suggesting I can use the engine connection, or do I need to find a separate busbar. Unfortunately I did not see any busbars easily accessible.

-- 
Jim Starkey


Jim Starkey
 

The reason to go through ALL is not a property of the switch but preserving the health of the diodes in your alternator.  Suddenly remove 100% of the load will cause the alternator voltage to spike zapping the diodes.  There used to be a product call Zap-Stop (essentially a Zener diode) that would protect the alternator diodes, but I don't think it's available anymore but a number of voltage regulators have a similar feature builtin.

A momentary short in a flood cell battery should have caused any significant discharge.  Think about the energy stored in a fully charged 12V battery and what would happen if it were instantaneously discharged.  I suspect you had a different problem...


On 3/23/2021 10:30 AM, Terry wrote:
Thanks folks, I learn so much from this site.

I think an ACR might be overkill for us (I don't have a brother-in-law and would not entrust the boat to anyone else) but I have an older solar panel that I want to install so that raises the question about a regulator to charge two banks of AGM batteries and maybe then an ACR would be useful.

The only issue with older battery switches is that you have to go through "ALL" to get from 1 to 2. I once had a battery dead short on me and I'm sure it drained the other bank when I went to switch over. I notice newer switches alow you to go through "OFF" to switch between the two banks. It was our one and only Coast Guard tow!

Terry

-- 
Jim Starkey


Harry Keith
 

Jim is right on this.  It is right in line with my aversion to things on battery terminals!

I put one of these on my Sabre when I redid the battery box area, and added one to our new boat within a year of purchase.  Really cleans things up.  Run a #6 or #4 back to the negative battery terminal, should be ample for all those little wires.   Note, I have a suspicion that these guys once were the OEM for Blue Seas -- the products really look like older stuff from Blue Seas.  The products are solid quality at great prices.

or

On Tue, Mar 23, 2021 at 10:48 AM Jim Starkey <Jim@...> wrote:
The best choice might be to recognize that the number of things that need an electrical ground is only going to increase and  ground bus bar in a quasi-convenient place would be a smart thing to add.  It would also give your ACR an accurate reference ground.