How am I supposed to wire Batteries properly?

[Ebtvision]

I'm rewiring my boat (27" Newport) shortly and need some clarification on how to wire the batteries. It'll be a starting and house battery (regular kind not gels or anything), going to a 1/2/All switch.

I'm not exactly sure where the negative terminals will go.

The positives of each battery will go to the appropriate positive terminals of the switch, how should I be connecting the negative terminals to my distribution panel?

I have a blue sea breaker panel with a negative bus bar and grounding bus bar. Somehow I need to get both battery negative terminals to the negative bus bar? And at the same time also get both battery negative terminals to one grounding wire to the engine bolt? I'm not quite clear on this.

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note: I was planning on wiring the alternator to the house battery so that it removes the risk of one of my kids hitting the switch while motoring, etc.

[sailorchic34]

Originally Posted by Ebtvision

I'm rewiring my boat (27" Newport) shortly and need some clarification on how to wire the batteries. It'll be a starting and house battery (regular kind not gels or anything), going to a 1/2/All switch.

I'm not exactly sure where the negative terminals will go.

Run the negative terminals to the engine, Generally same size as the + side. That's the common ground point. Then take a separate #4 (or #2) ground to the 12" ground on the panel.

From the battery switch, you take a full size + to the starter and a #4 (or #2) to the 12v panel.

[Ebtvision]

Originally Posted by sailorchic34

Run the negative terminals to the engine, Generally same size as the + side. That's the common ground point. Then take a separate #4 (or #2) ground to the 12" ground on the panel.

From the battery switch, you take a full size + to the starter and a #4 (or #2) to the 12v panel.

thanks, but what's going to the main negative bus terminal on the panel? The way you stated it (for the panel) I would have a main ground and main positive but no main negative.

[SteveInMD]

1/2/All battery switches are old school. These days one large bank is considered the best way to go. It's less hard on the batteries to have All on all of the time, draining them 1/2 as far down. Just use a simple On/Off switch rather than the 1/2/All. Add a separate starting battery if you can.

[Ebtvision]

Originally Posted by SteveInMD

1/2/All battery switches are old school. These days one large bank is considered the best way to go. It's less hard on the batteries to have All on all of the time, draining them 1/2 as far down. Just use a simple On/Off switch rather than the 1/2/All. Add a separate starting battery if you can.

I don't get what you mean. I'm using a separate starting battery, I'm using a starting battery and house battery, wired to a 1,2,all switch so that they can both be charged by the alternator. What's the alternative?

[Ebtvision]

Based on sailorchics instructions, I have this setup. I don't get where the neg bus bar needs to go now though, it doesn't seem like I should have all these multiple connections to a grounding lug.

[Stu Jackson]

Originally Posted by Ebtvision

I have a blue sea breaker panel with a negative bus bar and grounding bus bar. Somehow I need to get both battery negative terminals to the negative bus bar? And at the same time also get both battery negative terminals to one grounding wire to the engine bolt? I'm not quite clear on this.

----
note: I was planning on wiring the alternator to the house battery so that it removes the risk of one of my kids hitting the switch while motoring, etc.

House bank (-) >>> start bank (-) >>> NDP (negative distribution post - could be a bus bar or a Power Post) >>> to engine

Connect the electrical panel (-) to the NDP

Put the NDP anywhere you like convenient between the batteries and the engine ground.

Good idea to run the AO to the house bank, like these:

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: Basic Battery Wiring Diagrams

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
1/BOTH/2/OFF Switches Thoughts & Musings | SailboatOwners.com Forums

The Short Version of the 1-2-B Switch Stuff: Electrical Systems 101 This is a link to the Electrical Systems 101 Topic, reply #2

[SteveInMD]

OK - You want a simple On/Off for the house bank and use the 1/2/All as a way to pull in the house bank in case your starting battery goes flat.

As suggested, do some more reading before you start on this.

[Ebtvision]

wow I had no clue this would be so complicated thanks I'll have to read up on all this.

[Stu Jackson]

Originally Posted by Ebtvision

wow I had no clue this would be so complicated thanks I'll have to read up on all this.

Not really complicated, you just need another "point" to collect the wiring before the engine.

Here's the "why" of how it works:

OEM 1-2-B Switch Wiring History Alternator/Batteries & "The Basic" 1-2-B Switch BEST Wiring Diagrams

You may choose to noodle around here for more boat system issues:

Electrical Systems 101 Electrical Systems 101

[sailorchic34]

Originally Posted by Ebtvision

Based on sailorchics instructions, I have this setup. I don't get where the neg bus bar needs to go now though, it doesn't seem like I should have all these multiple connections to a grounding lug.

I have the same 12V panel. You could tie the negative and ground buses together. I did. That as on 12V panels, negative and ground is the same. I suspect blue sea OEM also does AC panels .

[Stu Jackson]

Originally Posted by Ebtvision

Based on sailorchics instructions, I have this setup. I don't get where the neg bus bar needs to go now though, it doesn't seem like I should have all these multiple connections to a grounding lug.

The red wire to the panel should come off the switch at the C post, same as the one to the starter.

Installing Battery Selector Switches (the "posts" in the back don't physically match with the switch positions on the front) http://c34.org/bbs/index.php/topic,6911.0.html

I already commented on the negatives.

[smac999]

Originally Posted by Ebtvision

I don't get what you mean. I'm using a separate starting battery, I'm using a starting battery and house battery, wired to a 1,2,all switch so that they can both be charged by the alternator. What's the alternative?

you use the blue sea add a battery kit. the switch keeps the batteries separated. and the acr charges both.

if you use a 1,2,all switch, you don't have a starting and house battery. you simply have 2 batteries. and no separation between engine and house loads. they are always from the same battery.

[Stu Jackson]

Originally Posted by smac999

you use the blue sea add a battery kit. the switch keeps the batteries separated. and the acr charges both.

if you use a 1,2,all switch, you don't have a starting and house battery. you simply have 2 batteries. and no separation between engine and house loads. they are always from the same battery.

That Blue Sea dual circuit switch is not recommended for sailboats, it's fine for runabouts and motorboats.

Here's why: AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
Darn AGM Batteries | SailboatOwners.com Forums

Please read the link, it's important.

An ACR can be added to the 1-2-B switch design as noted in my previous links, or you can simply use the B position on the switch when you're charging. Not so hard.

The second paragraph above makes no sense, because it's a battery selector switch. I may partially understand his poorly written paragraph, but if you read the links I provided earlier, there are various wiring and switching diagrams that address completely separating starting and house loads.

Your boat, your choice.

[smac999]

Originally Posted by Stu Jackson

That Blue Sea dual circuit switch is not recommended for sailboats, it's fine for runabouts and motorboats.

Here's why: AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
Darn AGM Batteries | SailboatOwners.com Forums

Please read the link, it's important.

An ACR can be added to the 1-2-B switch design as noted in my previous links, or you can simply use the B position on the switch when you're charging. Not so hard.

The second paragraph above makes no sense, because it's a battery selector switch. I may partially understand his poorly written paragraph, but if you read the links I provided earlier, there are various wiring and switching diagrams that address completely separating starting and house loads.

Your boat, your choice.

with a single swtich there is no separation of house and starter loads. both are on the common post coming from the same battery selected. unless you have multiple switches. I put the add a battery kit onto a lot of sail boats and they all work great.

your comment on sail vs motor makes no sense. all the electrical is identical and both will have the same issues. the only difference is power boats will have more charging time from alts.

the power boats I work on go the same places, drop anchor for the same amounts of time, and have similar power draws as the sail boats I work on. electriclly they are no different.