adding automatic charge relay and slight rewire

[Thank you dad]

First off, please forgive my awful system diagrams, not sure what everyone else has used to sketch out their systems, but they are using something better than me!


I currently have the classic, 1-2-B switch with everything running through the switch. I have a 120 amp alternator with a balmar 614H. Currently i have a single wire coming off the C post of the switch running to the starter with a short jumper going to the alternator. The electriction that installed the 614 wired the sense wire to a power wire coming off the alternator.


I have 4 lifeline group 31 house batteries wired in parallel for a house bank and 1 lifeline 3100 start battery.


Below should be an accurate layout.




My plan is to disconnect the start battery from the 1-2-B switch along with the wire going from the switch to the starter.


I will install a new On/Off switch with a direct connection from the start battery to the starter. Run a new cable from the alternator to the house battery and then put the Blue Sea ACR, that can be manually controlled so i can combine if needed, between the start and the house batteries as shown in the plan below. I will then move the sense wire for the balmar directly to a positive post on the house bank.


My questions for the group are, am I thinking this out right?


Where should i be installing fuses and what size fuses?


My Current xantrax battery charger has dual outputs, should i leave it as is or take the charging wire off the start battery and allow the charge current to be pushed through the ACR.

I currently have 200W solar through a MPPT that is also wired directly to the house bank.


Thank you again for your help
Jeff

[Stu Jackson]

Don't forget to remove the jumper from the starter to the alternator output.


Fuse at the battery ends, the ACR will tell you what to use for that.


Drop one of the shorepower outputs, let the ACR do its thing for ALL charging sources (to the house bank, you got that perfectly right).


By moving the start off the 1-2-B you're losing the ability to use either H or S for the boat. Might wanna rethink that unless your eletronics drop out. There are better wiring diagrams for that though.



Here are some:


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

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)
http://forums.catalina.sailboatowner...d.php?t=137615

This is a newer primer for boat system wiring design with a thorough digram: Building a Good Foundation (October 2016)
http://forums.sailboatowners.com/ind.../#post-1332240

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


Good luck.

[Thank you dad]

Originally Posted by Stu Jackson

By moving the start off the 1-2-B you're losing the ability to use either H or S for the boat. Might wanna rethink that unless your eletronics drop out. There are better wiring diagrams for that though.

Correct, i could not start off of the house bank alone, but could use the combiner feature of the ACR and start using both banks in an emergency.

[Stu Jackson]

Originally Posted by Thank you dad

Correct, i could not start off of the house bank alone, but could use the combiner feature of the ACR and start using both banks in an emergency.

That's the very last thing you want to do. Don't mix good with bad, anytime.



And it doesn't work that way. Combiners only combine when charging V is present.



If there is an emergency, you switch batteries, never connect them.


That's why the 1-2-B switch is so good. Just switch, never B, no rewiring required. Once you change to a USE only switch, you stop using B. B was only when it was a charging switch too, and before you had the combiner with the AO on the C post too, you'd need B to charge the second bank.


Unless you have serious electronic dropout using the house bank to start your engine, then keep what you have. This is all covered in the links I posted.


Happy reading, hope we might have saved you some work and the cost of a new switch and lugs. Good luck.

[Thank you dad]

Originally Posted by Stu Jackson

And it doesn't work that way. Combiners only combine when charging V is present.

https://www.bluesea.com/products/762..._-_12V_DC_500A


I believe that this ACR allows you to lock the batteries together if needed.



I have read some of those articles before and they are very helpful.


thanks

[Stu Jackson]

dad,


So it does. Still remains a useless tool and the last thing to do with a dead bank.


Think about it: good drains into bad right away. Not so good.

[john61ct]

Batts can be combined, but honestly if one side has failed, the other should be healthy & big enough to take over.

A shorted batt can instantly flatten the good one.

Charge sources should go to House. The VSR or echo charger keeps starter topped up.

The 1-2 switch redirects a load circuit between banks, not charging.

[CharlieJ]

For this exercise, remove the concept of "combining" or "paralleling" from the lexicon when discussing using the house battery to start the propulsion engine as a result of a failed dedicated starting battery. Instead, let's use the phrase "Emergency Start".

To build this emergency start feature, the propulsion engine has to have a standard ON/OFF isolation switch installed in the B+ from the start battery to the starter solenoid. BTW, this is an important feature that should be installed anyway and is called for by ABYC Standard E-11.

The Emergency Start Switch (ESS) is a second ON/OFF switch installed between the House Bank B+ buss and the load side of the starting battery isolation switch described above. I usually install a Blue Sea m/n 6004 with a removable plastic key https://tinyurl.com/y2y7kuy4 The ESS is OFF and the removable key is cable tied to the wire.

If the starting battery fails, OPEN its isolation switch to take it off line. CLOSE the ESS to bring the house battery capability directly to the propulsion engine starter with the failed starting battery.

[john61ct]

Or just use a properly wired VSR with the feature built in

[CharlieJ]

John
Absolutely correct.

The objection is that the Blue Sea m/n 7622 lists for nearly $300 and, to have full functionality, a Contura operating switch must be installed. The same amount of heavy wire has to be run to the ACR (VSR) as in the method I proposed so that feature is a wash.

The Blue Sea m/n 6004 lists for about $30.

[witzgall]

Ok, my take on this. Note I work for Balmar.

1. Consider running MC-614 the sense wire (with fuse) directly to the battery. One of the big differences between the ARS5 and the MC-614 is this seperate sense wire, to give you more accurate (and maybe faster) charging.
2. Consider using a Balmar Digital Duo charge instead of the combiner. Do this only if the start battery is only used for starting, and not other current draining activities (Bilge pump, and the like ok.) Why? Simplicity. You are only drawing tiny amounts of power from the start battery. The DDC excels at keeping the start battery charged and healthy. It is all that it does, and it is programmable and can work with different chemistries. So you can have AGM house, and sealed LA start. If you must have a paralleling function, that can be added. When my wife and I bought the boat we cruised on, it came with this setup. I learned to appreciate it (Before I started to work at Balmar) and have recommended it as the solution in your situation since. It simplifies wiring and does not require heavy cables, as it only works up to 30A of current without adding a relay (Which you should not need).

Chris

[smac999]

Originally Posted by CharlieJ

For this exercise, remove the concept of "combining" or "paralleling" from the lexicon when discussing using the house battery to start the propulsion engine as a result of a failed dedicated starting battery. Instead, let's use the phrase "Emergency Start".

How many damaged / failed batteries have you ever seen?

99% of the time you are dealing with a drained battery. Not a damaged battery. And paralleling is the way to go. Simple and works fine.

As to the battery charger. Leave both wires. It keeps reducancy if one charger output fails or the charger wire fuse blows. Either lead will be able to charge Both batteries via acr if the other stops. I have seen both those things happen.

[CharlieJ]

smac999 #12

In 19 years in the marine electrical business I have seen many damaged and failed batteries although I don't see the relevance to this discussion.

Paralleling, as I think we are using the term in this thread, is taking the output of the good battery and electrically connecting it to the dead battery. Depending on a lot of factors like wire size, resistance at terminations, length of wire, etc. the good battery may well provide a significant amount of its energy attempting to bring the depleted battery's OCV up and, hopefully, start the engine with whatever energy is left over. So, no, paralleling is not the way to go IMHO. Simple, yes; works fine, maybe.

Finally, what possible, rational objection, do you have to the simple addition of a $30 switch that will function as the Emergency Start Switch?