Questions about the Catalina 34 Electrical System Upgrade

[ptidwell]

I just completed the project described here on my 1989 Catalina 34.

https://www.c34.org/wiki/index.php?title=Catalina_34_Electrical_System_Upgrade

However, I did not upgrade my alternator.  I decided to save that for a future project.

The goal of the upgrade was to extend the utility of my house bank since I no longer need to conserve a whole bank for starting the engine.  It also addresses an intermittent starting issue I was having that seemed related to an electrical problem I just could not track down. 

As I drifted off to sleep last night, thinking about the new ease of boat operation I can now enjoy, I realized the electric fuel pump is still connected to the starting battery.  This is not addressed in the project write up or indicated in the diagram.

Diagram of Soliton's new electrical system
https://imgur.com/a/kDt0YzX

The pump only draws 1.6 Amps on average, while the echo charger will potentially deliver 15 Amps to the starting battery. So perhaps there is no problem here, but it is not true as the diagram indicates "Starting battery isolated and used only for starting." 

Should I move the fuel pump to the house battery, or will I be fine with it on the starting battery?

PS, as a bonus, I recreated and attached the "Revised" diagram from the original article.  The version on the article is impossibly small and difficult to read.

[Jon W]

Is your AC charger 20A or is that a typo?

[KWKloeber]

@P

Unless you've changed something the lift pump is powered by the same source as your panel, gauges, alarms, and blower.
Without having to decipher the upgrades, let's make it easy.  What's your concern with that?

I just completed the project described here on my 1989 Catalina 34.

https://www.c34.org/wiki/index.php?title=Catalina_34_Electrical_System_Upgrade

However, I did not upgrade my alternator.  I decided to save that for a future project.

The goal of the upgrade was to extend the utility of my house bank since I no longer need to conserve a whole bank for starting the engine.  It also addresses an intermittent starting issue I was having that seemed related to an electrical problem I just could not track down. 

As I drifted off to sleep last night, thinking about the new ease of boat operation I can now enjoy, I realized the electric fuel pump is still connected to the starting battery.  This is not addressed in the project write up or indicated in the diagram.

Diagram of Soliton's new electrical system
https://imgur.com/a/kDt0YzX

The pump only draws 1.6 Amps on average, while the echo charger will potentially deliver 15 Amps to the starting battery. So perhaps there is no problem here, but it is not true as the diagram indicates "Starting battery isolated and used only for starting." 

Should I move the fuel pump to the house battery, or will I be fine with it on the starting battery?

PS, as a bonus, I recreated and attached the "Revised" diagram from the original article.  The version on the article is impossibly small and difficult to read.

[Kyle Ewing]

Congratulations on your upgrade!  My fuel lift pump also runs from the starter battery with no issues.

If concerned that the stock alternator won't produce enough electricity to keep the starter battery charged with electric fuel pump draw, watch voltage while under way to ensure it doesn't drop.  How many amp hours reserve does your start battery have?

A lesson learned when I added a separate start battery: Make sure nothing else is inadvertantly consuming power from the start battery. In my case, the auto pilot was pulling power from behind the cockpit instrument panel.  I discovered this when I didn't see the current draw on my battery monitor.

[Ron Hill]

ptid : You didn't mention which engine you have, but I'll guess that it is an original M25XP engine.  The electric fuel pump should be wired so when you turn ON the key switch the fuel pump is energized!!     It should be OK on the starting battery!

A thought

[ptidwell]

Is your AC charger 20A or is that a typo?

Jon, the image attached to the post is a recreation of the original from the article.  That showed 20 Amp.  The charger on my boat (Soliton), is a Heart Interface Freedom 10, which documents says is 50 Amp (not sure how that can be since my AC input is only 30 Amp).

I am not sure what values are most likely.  Is 20A uncommon?

[ptidwell]

@P

Unless you've changed something the lift pump is powered by the same source as your panel, gauges, alarms, and blower.
Without having to decipher the upgrades, let's make it easy.  What's your concern with that?

KW, good point, everything on the panel, plus the blower are connected the same way. I became concerned because the project documentation indicates the starting battery is used for nothing other than starting the boat. I thought I may have misread the diagrams or instructions.  The responses here make me think I don't have much to worry about.

[ptidwell]

Congratulations on your upgrade!  My fuel lift pump also runs from the starter battery with no issues.

Kyle that's good to hear!  Did you do the alternator upgrade at the same time?
I will definitely monitor how the charging is going.   The battery spec says there are 130 reserve minutes.

I am curious where you mounted your starting battery.

[ptidwell]

ptid : You didn't mention which engine you have, but I'll guess that it is an original M25XP engine.  The electric fuel pump should be wired so when you turn ON the key switch the fuel pump is energized!!     It should be OK on the starting battery!

A thought

Ron, you are correct.  It is an M25XP and is wired just as you described.  Sounds like I may be ok.  Thanks for you input!

[ptidwell]

I would not mind updating the original article with refreshed images and any other updates the article might need.  Does anyone here know how I might go about doing that?

[Jon W]

ptid, with a house bank of 4 T105's you want your AC charger to be 40 to 50a range. If yours is 50a you're good.

When I was doing my upgrade I was given the guidance that the AC charger should be sized at ~10% of the bank it is directly charging.

[KWKloeber]

I'm wondering, why do you feel you need a "starting" battery, opposed to a "reserve" battery to be used only in an emergency (the house back is down?

We're did you read that about the battery used only for starting, nothing else?

@P

Unless you've changed something the lift pump is powered by the same source as your panel, gauges, alarms, and blower.
Without having to decipher the upgrades, let's make it easy.  What's your concern with that?

I just completed the project described here on my 1989 Catalina 34.

https://www.c34.org/wiki/index.php?title=Catalina_34_Electrical_System_Upgrade

However, I did not upgrade my alternator.  I decided to save that for a future project.

The goal of the upgrade was to extend the utility of my house bank since I no longer need to conserve a whole bank for starting the engine.  It also addresses an intermittent starting issue I was having that seemed related to an electrical problem I just could not track down. 

As I drifted off to sleep last night, thinking about the new ease of boat operation I can now enjoy, I realized the electric fuel pump is still connected to the starting battery.  This is not addressed in the project write up or indicated in the diagram.

Diagram of Soliton's new electrical system
https://imgur.com/a/kDt0YzX

The pump only draws 1.6 Amps on average, while the echo charger will potentially deliver 15 Amps to the starting battery. So perhaps there is no problem here, but it is not true as the diagram indicates "Starting battery isolated and used only for starting." 

Should I move the fuel pump to the house battery, or will I be fine with it on the starting battery?

PS, as a bonus, I recreated and attached the "Revised" diagram from the original article.  The version on the article is impossibly small and difficult to read.

[KWKloeber]

I would not mind updating the original article with refreshed images and any other updates the article might need.  Does anyone here know how I might go about doing that?

Yes but I've lost access so it's difficult to assist you to do that.
Maybe one day I'll regain access.

[KWKloeber]

Is your AC charger 20A or is that a typo?

Jon, the image attached to the post is a recreation of the original from the article.  That showed 20 Amp.  The charger on my boat (Soliton), is a Heart Interface Freedom 10, which documents says is 50 Amp (not sure how that can be since my AC input is only 30 Amp).

I am not sure what values are most likely.  Is 20A uncommon?

Are you understanding electrical circuits or just following an A B C upgrade like a paint by number?  You can't equate current @ 12v to current @ 120v in that manner.

50 amp output @ 12v would require 5 amp input @ 120v. That's a perfect world with the efficiency of the charger being 100%, which it's not. If it's more like 80%, the draw would be like 6.3 amps.

[waughoo]

I am curious where you mounted your starting battery.

I too am curious to know where you put it.  I am planning this project for the winter.  Present location I'm looking at is under the aft bberthdirectly aft of the footwell bulkhead.