Help with Battery Wiring

[RolfP]

I need some help with my wiring plans. I am trying to get on a path from original 1982 wiring to current practice. I have attached two PDF pages of my wiring: Current Battery (not good!) and what it (maybe) SHOULD BE as best I can figure out from months of research and reading here, and elsewhere. I have tried to incorporate everything I've read here and elsewhere, but I need a review. It is likely that I've missed some important detail. I have four questions, also found on the 2nd page of the PDF:

1. I’m planning on the Blue Sea SI-ACR 7610, do I have this wired right?

2. Where should I put an on/off switch? Do I need one or more than one? Should I buy the 3 switch panel from Blue Seas and remove the B-1-2 switch?

3. How would I make sure my instruments are isolated from the “start” of the motor? Threads on this suggest more than just poor connections

4. MOST IMPORTANT: Is there anything wrong with my diagram? I know I have to re-think my fuses and wire sizes, but I need to know that I am creating a “best design” for the connections between all the major components: Battery, 1-2-B, ACR, Engine Start/Alt, Shunt, and Buss Bars. I also want to upgrade to 440ah or 660ah via T-105 batteries eventually

For right now I am hoping to make these changes, install my new bilge pumps, get the boat back in the water, and go travelling for a few months.

BTW - If I knew how, I would post the pictures instead of the attachments, anyone who know how is welcome, and I'll look for instructions as well.

[smac999]

the acr is fine. it could also just join direct to each battery post. your engine is starting off your house battery though...

so I would get 3 switches. house / engine / parallel. blue sea makes a single swtich that will do this but some people don't seem to like it.. I use lots of them.

generally heating systems (espar etc) are unswitched as they require a cool down period when turned off.

[RolfP]

Thanks SMAC, its nice to hear confirmation. Most of my boat was either original wiring or previous owner updated, or me updating knowing nothing. I know more now.

Do you mean the Blue Seas "Traditional Metal Dual Bank Battery Management Panel"? This is the one I was thinking I should replace my 1-2-Both with. Does a person just put both the House and Start switches to on all the time when moving the boat, and turn off Start when docked, anchored, moored, or absent?

I see what you mean about the House wired for starting and this is not what I really want. I have read there is a way to wire the 1-2-B switch to use the house to start the engine, keeping the "start" battery always in reserve. However, right now I loose my AP if I start the engine, presumably from a voltage drop, so I am looking for a way to avoid this. As I understand it, if I get the Blues Seas Switch, then when not "combined", the "start" always starts the motor, the "house" never does. However, I have also read that if your start dies then using the combiner ends up bleeding off amps from the house to the start battery at the same time you need those amps for turning over the engine. So I'm confused on the best way to go, or maybe there isn't one? My best world would be to 1) have the start always start the engine unless it died, 2) then switch to only house for turning over the engine, 3) always charge the house first, then the start, 4) be able to set the switches one way, always, and forget them, unless one set dies.

Any suggestions on this?

Makes sense on the heater - I have Webasto and it does require a cool-down, I'll make sure to check the manual to ensure its wiring is accommodated, it looks right in the original system.

[Stu Jackson]

Originally Posted by RolfP

I have read there is a way to wire the 1-2-B switch to use the house to start the engine, keeping the "start" battery always in reserve. However, right now I loose my AP if I start the engine, presumably from a voltage drop, so I am looking for a way to avoid this. As I understand it, if I get the Blues Seas Switch, then when not "combined", the "start" always starts the motor, the "house" never does. However, I have also read that if your start dies then using the combiner ends up bleeding off amps from the house to the start battery at the same time you need those amps for turning over the engine. So I'm confused on the best way to go, or maybe there isn't one? My best world would be to 1) have the start always start the engine unless it died, 2) then switch to only house for turning over the engine, 3) always charge the house first, then the start, 4) be able to set the switches one way, always, and forget them, unless one set dies.

Any suggestions on this?

Any suggestions on this?

Sure.

You said you've been reading on this forum. If so, then you almost MUST have seen these links, which I and many others have posted so many times that I've asked the mods to make it a sticky.

They answer your questions about switching.

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

This is a newer primer for boat system wiring design with a thorough digram: Building a Good Foundation (October 2016)
Building the DC Electrical Foundation | SailboatOwners.com Forums



They come from here:

Electrical Systems 101

The Blue SEa switch is not good for sailboats. 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

[RolfP]

Thanks Stu - I reworked my diagram in light of what I've been learning on all those pages. I've been reading and re-reading them for days, but some new diagrams you pointed to have helped.

[Privilege]

The ACR is voltage sensitive. If your house batteries are not receiving an incoming charge, the relay will remain closed and not allow one bank to drain into the other. Your diagram is sound although, as pointed out your engine starter is being fed from your house bank. I would lean towards having a separate switch for emergency paralleling the two banks in the event that you have trouble starting your engine - which is always the priority. With luck you should never have to use it so you can install it and forget it. With your set-up. you will still have the occasional worry of having the two banks connected if the switch is not switched correctly.

[RolfP]

I am struggling to understand how to get the House battery directly wired to the engine alternator (as well as the shore power charger and solar) so it is charged first while the engine is running, and at the same time, have the Start Battery be used to start the engine, not the house battery. My AP kicks off when I start my engine from the house side currently.

As I understand it, one or the other of the + House or Start Batt needs to go to the Starter/alternator + side, and depending on which one, that is the one that always starts the motor.

Or can they both go there?

Or can I put the House Batt direct to ALT and the Start Batt direct to Start?

It seems I'm getting close. If it helps, I have a Perkins 4-108 and 100amp Balmer with MC-614, Genasun for solar.

[smac999]

Originally Posted by RolfP

I am struggling to understand how to get the House battery directly wired to the engine alternator ]

remove the wire between alternator and starter post. and run a new longer wire from alternator to house bank. of proper size for the lengh. to the unswitched anl fuse block. leave the starter wire going to the start swtich.

make the start battery anl 300a (or an MRBF which is easier)

don't switch the house battery line. just fuse it with ANL or MRBF
or if ANL block is close to battery (5') I wouldn't even bother.

the way the 2 switches are wired is a little weird. but as long as you label it and know how it works you'll be ok. there are different combos of swtiches on and off that will do different things, and you'll have to know each of them. using two 1,2,all would be a bit simplier to understand.

the solar and heaters likely don't need expensive anl fuses / fuse blocks and could go on the smaller fuse block below.

VHF normally switched

the AM/FM is only the mem. 2nd line should be on panel

[chala]

Originally Posted by Stu Jackson

then you almost MUST have seen these links

Perfect example of

Originally Posted by chala

very poor electrical installations

Originally Posted by chala

It would be preferable to show acceptable drawings.

[RolfP]

THANK YOU ALL for the HELP and TIME looking at this. I have updated my plan based on thoughts from SMAC and others.

My revised plan looks like this:



What I intend by this plan is that my Batteries will always be charging when my shore power, alternator, or solar panels are generating power, and my unswitched items will always have power from my house batteries.

If the House batteries die, then I can put the 1/2/B to 1 and the on/off switch to ON, and start and run the engine. While the engine is running the House batteries will charge, followed by the Start.

If the Start battery dies, then I can put the 1/2/B to 2, the on/off to OFF and start the engine from the House, then switch the 1/2/B back to 1. The Start will be charged through the ACR.

Again, happy to hear suggestions and corrections! This picture is the current state of affairs with the batteries removed, shunt to bottom right, 1/2/B, PDP, and Windlass breaker ahead. I believe I will be able to install all the new parts in here, and with some effort, label and organize all the wires.

[smac999]

looking better. I would fuse the alternator line as it goes into the house distro post. you can use an MRBF fuse on a post. 150% bigger then the alt rating.

also make sure the ACR fuses as close to the posts. once again you can use MRBF's for this right on the posts. makes wiring much easier.


yes engine neg can go to neg bus bar.

if you use something like the this for the fuse block
https://www.bluesea.com/products/502..._Bus_and_Cover

you can also run a single neg to the block, and then all the small negs don't have to go all the way. then can all end at the fuse block with the pos wires. not a big issue if the fuse block is near the neg bar. but helps alot if far away

depending on charger size and fuse size it may need to get wired to the pos post with a bigger style fuse.