Battery switch/charging question

[tmjb]

I have just installed a Xantrex Echo-Charge battery charger which, by my understanding, enables me to charge my starting battery from my house, keeping the two separated, and to charge only my house from my alternator thus preventing overcharging of the starter battery.

My question is this: Since the starter battery is isolated from the rest of the boat electrics and dedicated only to starting do I need a master on/off switch for this battery? If so I would only need a single circuit master switch to disconnect the boat's electrics from the battery.

A follow up to this, if the above is true, is can I connect the alternator directly to the house bank rather than via the master battery switch thus avoiding the possibility that the alternator might be run without the battery (if the master switch is not switched on) and thus avoid damage to it?

I would much appreciate any thoughts, advice etc.

Many thanks in advance.

 

[MattM83]

in my boat i used a 1,2,both,off switch for my starter battery, that way i can use my house bank for starting if something happend to the start battery. i simply connected common to the engine, 1 to the starter batt, and 2 to the main house buss. imo switches are the better way to go. and if someones playing with your battery switches while your underway i think you have ground to throw them off your boat.

 

[JamesG161]

I think you got it backwards. Alternator is a crude charger for starter batteries, high output. Charger is for deep cycle house batteries. Crossover in a pinch.
Jim...

 

[Maine Sail]

I think you got it backwards. Alternator is a crude charger for starter batteries, high output. Charger is for deep cycle house batteries. Crossover in a pinch.
Jim...

Actually the vast majority of cruisers use the alternator for charging. Some factory alts, such as the Hitachi's & Valeo's, are a rather poor choice if you need fast charging, but they work for many weekenders...

Some, with bigger boats, and gensets, will also use a large I/C to charge but I will take the simplicity of a high output alt and Balmar reg on the AUX eng over a genset for most any boat below about 42'..

It would be a complete waste to feed an alts output to a start battery that does not need it and can not utilize the charging potential and this is what his Echo Charger is for..

 

[Maine Sail]

I have just installed a Xantrex Echo-Charge battery charger which, by my understanding, enables me to charge my starting battery from my house, keeping the two separated, and to charge only my house from my alternator thus preventing overcharging of the starter battery.

My question is this: Since the starter battery is isolated from the rest of the boat electrics and dedicated only to starting do I need a master on/off switch for this battery? If so I would only need a single circuit master switch to disconnect the boat's electrics from the battery.

A follow up to this, if the above is true, is can I connect the alternator directly to the house bank rather than via the master battery switch thus avoiding the possibility that the alternator might be run without the battery (if the master switch is not switched on) and thus avoid damage to it?

I would much appreciate any thoughts, advice etc.

Many thanks in advance.

An on/off for start should still be installed as well as consideration for a switch scenario,to cross-use the banks in the event of a failure. Connecting the alt to house, or any other charge source, directly to house, is a requirement for the Echo to work properly....

 

[tmjb]

Thanks all for your input. Always much appreciated.

To be clear I am using my alternator to charge the house bank and the Echo-charge to charge the start batt from the house bank which avoids overcharging of the start battery if subjected to the same charge cycle as the house (as when the main batt switch is switched to all).

Mainesail I understand that the Echo-charge needs connection of the alternator to the house bank. My question is why not do so directly rather than through the master switch which I thought was convention (?). Maybe I'm wrong re the latter. Direct connection would surely avoid the possibility of frying the alternator by starting the engine with the main switch turned off (In my current setup as described above)?

I also understand the desirability of being able to switch the battery source to the starter to the house in emergency. I need to think about how to do that while also avoiding connecting the house to the start battery directly.

My question re a master switch between the start battery and the starter is what make a boat different from a car in this regard?

 

[Maine Sail]

Thanks all for your input. Always much appreciated.

To be clear I am using my alternator to charge the house bank and the Echo-charge to charge the start batt from the house bank which avoids overcharging of the start battery if subjected to the same charge cycle as the house (as when the main batt switch is switched to all).

Mainesail I understand that the Echo-charge needs connection of the alternator to the house bank. My question is why not do so directly rather than through the master switch which I thought was convention (?). Maybe I'm wrong re the latter. Direct connection would surely avoid the possibility of frying the alternator by starting the engine with the main switch turned off (In my current setup as described above)?

I also understand the desirability of being able to switch the battery source to the starter to the house in emergency. I need to think about how to do that while also avoiding connecting the house to the start battery directly.

My question re a master switch between the start battery and the starter is what make a boat different from a car in this regard?

I have yet to see a start battery "cooked" from over charging via BOTH or a combiner. This is really in the "myth" department for far too many reasons to go into right now but I bet Stu will post a link or two.....

 

[tmjb]

MaineSail, are you saying that the Echo-charge (or equivalent Balmar Duo Charge) are in your opinion a waste of time?

Do you consider something like Blue Sea ACR a better bet for keeping the house and start battery circuits properly charged but separate?

Apologies if I'm going over old ground. I've read a number of articles/posts about this (including some written by you) but, if the Echo-charge/Duo charge are not good options, I'm confused at this point.

 

[woodster]

actually the echo charger is a very good option and maine has endorsed it for a very long (that's how i found out about it ) time if you go to his musings or his pbase site you will find an article on this...

 

[Maine Sail]

MaineSail, are you saying that the Echo-charge (or equivalent Balmar Duo Charge) are in your opinion a waste of time?

Do you consider something like Blue Sea ACR a better bet for keeping the house and start battery circuits properly charged but separate?

Apologies if I'm going over old ground. I've read a number of articles/posts about this (including some written by you) but, if the Echo-charge/Duo charge are not good options, I'm confused at this point.

The Echo and Duo and Combiners are all great options. My point is that is is a myth to not choose a combiner because you "heard" it will cook your batteries. I probably install more Combiners than Echo or Duo's but it's application dependent... If all you need is an Echo it is a great device....

 

[Capt jgw]

My house bank is up in the bow, so when I installed the combiner I connected the alt output to the #2 post on the 1-2-both switch which is also wired to the house bank. Alt output is then effectively connected direct to the house and I can still select 1, 2 or both to start. Don't know of this is exactly proper, but it works on my boat.

 

[Stu Jackson]

Maine Sail's MYTH - a good read

Gee, links? Ya think?!?

Overcharging with Combiners or ACRs The MYTH:
http://c34.org/bbs/index.php/topic,7052.0.html

These answer your question about switches:

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

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.sailboatowners.com/showthread.php?t=137615

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Since you installed an echo charger, you should read this, too:

Echo Charger Use Warning from Maine Sail: http://www.sailnet.com/forums/electrical-systems/72295-xantrex-echo-charger-rant.html

All these comes from here:

Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html

 

[tmjb]

Thanks again all.

Too many options. I need to do mor reading and figure out what works best for me.

I'm still not clear if there is any reason not to hook the alternator output directly to the house bank or the starter directly to the starter battery.

 

[Maine Sail]

Thanks Stu. I am actually under sail right now on AP using my phone....... Can't say too much and trim sails and dodge lobster pots.. (Wink)

 

[tmjb]

Many thanks for fitting me in between sail trim and obstacles MaineSail.

 

[Stu Jackson]

Thanks again all.

Too many options. I need to do more reading and figure out what works best for me.

I'm still not clear if there is any reason not to hook the alternator output directly to the house bank or the starter directly to the starter battery.

You're very welcome, glad to help.

Actually, there aren't that many options. Only two or three depending on how many switches you want to bother with and whether or not you think separating the reserve bank for starting is what you want to do. The first link after the myth one explains those.

Any reason? Sure: blown diodes on an alternator. That enough for you? Seriously, once you move the AO off ANY switch, you (as noted in the texts) are safer:

Please note that in BOTH cases the ... switch is used as a "USE" switch, only "deciding" which battery bank to take power OUT of. The AO goes TO the house bank, NOT to the C post of the battery switch. The advantage is that the ... switch operation can NEVER blow the diodes out of the alternator. You can even turn the danged switch OFF with NO damage!!!

And if that's not enough, an alternator rebuild can cost anywhere from $75 to $150 plus the time to take it off and put it back on.

Anything else, please let us know.

 

[tmjb]

Thanks again. Obviously I wasn't being clear in what I wrote. If I understand you correctly you are advocating what I was suggesting, i.e. connecting the AO directly to the house bank thus avoiding the possibility that the alternator diodes can get fried by the engine running with the battery switch accidentally switched off.

Did I miss an answer to why not connect the start battery directly to the starter without a master switch - as in a car? Apologies in advance if I did and/or missed the point re this topic.

 

[Stu Jackson]

Did I miss an answer to why not connect the start battery directly to the starter without a master switch - as in a car? Apologies in advance if I did and/or missed the point re this topic.

I'll take a stab at this one, now that I saw your earlier question, sorry I missed it then.

I see two reasons:

1 You start your engine but the starter sticks. How do you turn it off? Without a switch, you have to remove wires from the start battery. Not such a good idea: takes longer, right?

2 The switching diagrams in the links ALWAYS provide you with an opportunity to use the start battery to provide LIMITED house loads in case the house bank fails (rare, but it happens). Without a switch, you can't.

Does that help?

 

[JamesG161]

I read this thread with great interest. I was scratching my head and finally went to Xantrex site and read about this Xantrex Echo-Charge and what it does and how to install it.

I was impressed in its use, but a no time did it suggest using it to charge using an alternator.

IMHO it is a smart switch that uses an I/C to charge a completely different type of battery, like a high amp output starter battery. NOT the Reverse. The installation diagram does not substitute for the Alternator to Start Battery circuit but allows the I/C to charge the start battery. Please note that the House/Start batteries should be of same type wet or AGM.

It detects the "smart charger" on deep cycle house batteries and does the automatic switching function instead of a disconnect switch. (I have a set of jumper cables to do the same manually in a pinch or a jump start to start my genset and its alternator charges the starter battery.)

Direct quote from Xantrex...

Xantrex's echo~charge conveniently charges auxiliary or starting batteries from an existing charging source, such as a battery charger or inverter/charger.

Normally Larger boats have this sophistication to separate the charging types.

Most Alternators are NOT designed deep charge and use a smart (save your house battery) charging curve.

If your boat uses the alternator to charge you deep cycle, then your Alternator is "smart" and this device is not needed.

Jim...

 

[Stu Jackson]

Echo charger

Jim, sorry, but you're wrong. "Such as..." means ANY charging source. That's how it works.

PS [added later] - We've (Maine Sail, me and some others) been discussing echo chargers since they were originally made before Xantrex took them over from Heart or Ample (one of the good guys in Seattle). That's over 15 years.

Maine Sail wrote this, too:

Echo Charger Use Warning from Maine Sail: http://www.sailnet.com/forums/electrical-systems/72295-xantrex-echo-charger-rant.html