Stu's Wiring Diagram & The 1-2-B & Dual Circuit Switches

[Tom Soko]

Gary,
I've followed this thread, and just had to stick my $0.02 into it.  I didn't see where you mentioned that you were planning to install a separate starting battery, in addition to the 4 house batteries.  If you do, I would highly recommend a new type of battery switch to replace the 1-2-B switch installed now.  It's the dual circuit Blue Seas #5511e
http://bluesea.com/category/1/products/5511e
For 99% of the time it is a simple on/off switch, connecting the house batteries to the house load, and connecting the starting battery to the starter.  IF it is ever needed, another 1/4 turn of the switch, and you can combine all (5) of your batteries for an emergency start. I installed one on a friend's boat (he's mechanically challenged), and it's been perfect. 
Many years ago I installed an Ample Power EMON on my boat.  After 17 years it finally gave up the ghost, and two years ago I went looking for another energy monitor.  I was told that the Link 10 was no longer in production, so I bought the XBM.  In short, it has been wonderful.  It measures the house bank, which is really all I have a need to do.  Hope this helps

[Stu Jackson]

It would also be helpful to read this, from Tom's reference:  http://bluesea.com/viewresource/69

You see this "new fangled" switch is just another switch.  I do not yet see it's difference from a 1-2-B switch, because it provides ALMOST the same functionality.  Either of the two battery banks or Both will provide power to the only two outputs that should be coming off a switch:  the distribution panel and the starter.  I'd be pleased to learn more about this switch, but I just can't justify recommending it when it costs more and seems to require the ACR to make it operate to charge the reserve bank automatically, which is no different than an ACR, echo charger or combiner or oil pressure relay for a 1-2-B switch.

[Tom Soko]

Stu (and Gary),
I should have been more clear in my explanation.  My house circuit is separate from my starting circuit.  The house bank feeds the house load, and the starting battery feeds the starter.  My alternator output goes directly to the house bank, and is NOT connected to the starter.  I wired it this way so that the house bank can be left on, and the starter circuit can be left off.  The only time the two circuits are combined is when I combine them.  I have an on/off switch for the house load, and I have a 1-2-B switch for the starter.  If the Blue Seas dual circuit switch had been invented when I re-wired my boat, I would have bought it.  It would have eliminated the need for a second switch for me. 
If on the other hand you do not separate the starter from the house load, then the OEM 1-2-B switch would work fine.  Hope this helps.

[Stu Jackson]

Tom, it certainly is amazing how many different ways there are to arrange electrical systems on our boats.

I believe there are two very important things skippers should keep in mind when wiring (or rewiring) their boats:

1.  Remove the alternator output from the 1-2-B switch (or any other combining switch) and run it directly to the house bank.  This assures that the current flowing to the banks when the alternator is running is always ON and avoids someone from turning the switch and frying (possibly) the alternator diodes.  It also completely avoids the issue of having to have the 1-2-B switch in the B position to select which bank(s) to charge.  This assures that the 1-2-B (or any other switch) is ONLY being used to decide which battery bank is being used to either start the engine OR to run the house electrical distribution panel.  Because so many boats were built with the alternator output going to the 1-2-B switch, too many skippers thought they had to start their engines on BOTH because they thought they needed the power, which was, and still is, just plain wrong.  It was because they needed to use the switch to charge both of the battery banks when the alternator was producing, because the alternator output was put on the common "C" post of the switch by the factory.  In most cases, with a good reserve bank, the switch could just as well have been left on the house bank, but the power went from the alternator to the switch to the banks in what usually then became undersized OEM wiring for higher output alternators.

2.  Find an appropriate (easy to understand) method of charging the emergency reserve backup (sometimes incorrectly called the "start" bank) from single output sources which are the most prevalent in most boats (few folks have dual output alternators).  This can be any of the relay types, another switch or just using BOTH, which parallels the batteries even if the alternator output goes directly to the house bank.  In fact, there's really no reason to ever have to parallel the two banks, because if one doesn't work the other should and putting them together to start makes little sense if one is "dead."  That's the BIG "problem" with the new dual circuit switch. The only need to parallel is for charging, which can be done with switches or relays, and reserve banks rarely need to be charged given their use, since so little is taken out, even with glow plugs and numerous starts (you can get an awful lot of starts out of a 'meager' 60 ah reserve "start" battery without recharging, at from 2 to 5 amp hours per start because the high amperage draws are of such short duration).

I do not dismiss the new switches completely because perhaps making things "easier" for people to understand is certainly good, but I don't buy the hype that it is better - it still does ALMOST the same danged thing as the old 1-2-B switch.

I encourage people to understand what they have so they know how to properly use it.

[jmnpe]

Here are few random comments on various topics emerging in this discussion, in no particular order.

Xantrex Echo Charge Function If you are using the built-in function contained in the larger Freedom Series inverter/chargers, be advised that you do not want to use the Echo Charge function with any low internal discharge batteries: i.e. - any form of AGM or Gel battery technologies. The way the Echo output(s) receive their power internally in the Freedom unit causes high voltage spikes to propagate through the Echo output and can result in float voltages appearing across connected low loss batteries up to 16 volts. This will result in rapid degradation of the positive plates in the battery and seriously reduce the useful life of the batteries. I haven't specifically looked at the stand-alone Echo charge module in detail, but I have seen the same problems appear with them when used with a few older chargers and some alternators that had "dirty" outputs.

Link 10 Replacement The old Link 10 has been directly replaced by the new Link LITE, and with one or 2 features unavailable in the basic Link 10. Of particular interest, the Link LITE provides for the display of a second battery voltage on the internal display much like the Link 1000 provided. The accuracy of the Link LITE is comparable to the original Link 10, and I think retails for a little less than the Link 10.
The Link PRO has all the features of the LITE but at higher internal accuracy for voltage and current measurements, and therefore all computed charging parameters are also more accurate. The PRO also offers a few features not available on the LITE, and the retail price is about 15 to 20% higher than the PRO depending where you buy it.

Truecharge2 I noticed that Xantrex has now dropped the ridiculous idea of having this charger available in 7 different output current levels. It is now produced in either 20 or 40 amps like it's predecessor. If you are using flooded cells, you will definitely be using the equalize function, and without the optional remote panel you will only be able to activate the equalize function from the control panel built into the charger, which means you will have to provide for physical access to that part of the charger unit. Unlike the remote panel option for the Truecharge+ series ( which was almost worthless ), the remote panel for the Truecharge2 will let you fully utilize/program any features available from the charger.

Microwave Ovens and Psuedo-Sine Wave Inverters  With a large fully charged battery bank, a non-smart "psuedo-sine wave" ( i.e. bastardized square wave ) inverter will sort of work a microwave, but always at reduced power output.  I have used one that way, and it was better than heating up the cabin in the summer with the regular stove or oven. As the battery voltage reduces, however, the microwave power starts to drop in a hurry and quickly becomes almost useless.
If you want to use the microwave a lot and effectively, you will have to go with a smart true sine wave inverter that will allow the microwave to maintain it's normal peak power output over a larger battery output voltage level range. As an added bonus, the microwave and some fans and power tools won't "growl" at you as the battery voltage level drops.....

Xantrex XC Series Chargers In my on-going evaluation of this product, I have discovered some disturbing characteristics when used with low internal loss batteries ( AGM for sure, and maybe Gel ) that I have discussed with Xantrex personnel and am still awaiting their response to my disclosures and questions. I'll update my previous product review on Xantrex chargers once I have received a response from Xantrex. For now, I will caution everyone to only use the XC Series chargers with flooded cell batteries.

Regards,

John
C34 Otra Vez
1988 wing keel
Hull 728

Copied to the Battery Charger Evaluation thread (http://c34.org/bbs/index.php?topic=4352.0)  November 10, 2008 - Stu

[Stu Jackson]

For the new Dual Circuit switches, if you follow the wiring and the switch positions, you'll see that it has a limitation, an unintended consequence if you will, that the old 1-2-B switches do not have.

The dual circuit either separates the reserve and house banks or combines them.  There is NO position on the new switch that allow JUST the reserve bank to provide power.  So, if your house bank is dead flat (for whatever reason), putting the dual circuit switch in the combined position means your reserve bank is gonna bleed into the dead house bank.

That concept is basic stupidity for using battery banks.

The ONLY thing it's good for is isolating electronics by always starting on a separate ("start" not reserve) bank than the house bank.  A much better way to do this is to buy a separate very small (PWC type) 12V battery for your electronics, because paralleling a good bank and bad one is nonsense.

The advantages of the 1-2-B switch is that the house bank can be completely disconnected from any load and the reserve bank can be used for (albeit controlled and limited) house loads.

Added June 2022:  for anyone reading about those DCP switches, recently the COMPLETE "How To" wire them properly to avoid the issue I wrote about in this and many other DCP threads has been documented.  While I've added this to the Elec Sys 101 Topic, I include them here, too.  Without using THREE switches - instead of ONE 1-2-B switch, a DCP switch is potentially very dangerous if your house bank goes dead.

How to properly wire & switch a DCP switch - Maine Sail's "workaround" explained Replies #28 & 29
https://forums.sailboatowners.com/threads/what-size-fuse-for-automatic-charging-relay.1249932137/page-2

Maine Sail's DCP Wiring Diagram
https://forums.sailboatowners.com/threads/operating-the-house-start-battery-selector.1249933496/#post-1745066

[Gary Brockman]

My plans for upgrading my boats electrical system changed yesterday morning when a sales rep from Xantrex told me that they have yet to start production of the Truecharge2 remote panel which I had on order and need given my planned location for the changer (under the chart table against the head bulkhead). The sales rep told me that Xantrex hopes to start distribution of the remote panels by the end of the year (but he could not guarantee it). Not wanting to wait until the first of the year for the remote, or even longer if there are delays in manufacturing, I returned my Truecharge2 20 amp charger uesterday afternoon and ordered a XC3012 charger instead. The cost difference ($209 vs. $389) should work out about the same given that the XC3012 comes with a battery temp sensor and the control panel can be removed and used as a remote.

I am planning to start this project Saturday and will update this thread as I go.

- Gary -

[jmnpe]

Hi Gary,

One thing you need to know about the remote location option of the panel in the XC series charger is that while it can be removed from the main unit, there is no mounting means provided for it except for some rather permanent adhesive backed tape already in place around the periphery of the panel. If you ever want to be able to remove it from a mounting location, you will have to make a backing plate with a cutout to permanently mount the remote panel onto, and then mount the backing plate + remote panel assembly with screws in the corners. Not a very well thought out design detail in my opinion. The lip around the panel is relatively small, and drilling mounting holes in it could result in warranty issues in the future.

Also, as I noted previously, the XC series chargers for now(?) should only be used with flooded batteries because of over-voltage issues in the float mode with AGM batteries.

Regards,

John
1988 C34 wing keel
Hull 728
Otra Vez

[Stu Jackson]

Good luck, Gary, sounds like you've thought this one out pretty well.

This is a copy of my wiring diagram which uses the 1-2-B switch.  It was part of my Nov. 2006 Alternator Regulator Mainsheet Tech Notes article.  I finally got it into a jpg after making it up in Word Draw. [Stu wiring diagram]

You may also be interested in this thread from co.com:  "Engine Starting and Real World Amp Draw" http://forums.sbo.sailboatowners.com/showthread.php?p=580988

It discusses the actual draw of starting an engine, separate reserve emergency banks, the 1-2-B switch and electrical systems.  It reflects some of what we've been discussing here, and includes a nifty video!  It was originated by Maine Sail, who has been active here on our board, too.

Here's another good discussion and summary, bottom of page 1, then most of it is one page 2.  http://forums.catalina.sailboatowners.com/showthread.php?t=104505

I've since added the battery sense wire from the regulator to the house bank.

[Stu Jackson]

Another unintended consequence of the dual circuit switch:

The diagrams in the West Marine catalog show an outboard motor as the "engine" for the wiring diagram.  This seems to imply that the engine includes BOTH th alternator (energy output device) AND the starter (energy consumer).  The most important part of the diagram's wiring is missing:  the wires FROM and TO the alternator and the starter, assuming that the "engine" performs both functions.