Echo Charger

[Neil McDonald]

Before deciding how to upgrade my electrical system, I need a better understanding of the performance difference between installing an echo charger and a battery combiner. I have neither at present but do have a pair of 6V golf cart batteries as my house system and a single 12V starter battery installed, both banks connected in parallel to a 3 stage Xantrex Truecharge 40 smart charger.

As I understand it, with a combiner setup the two batteries are effectively connected together under any charging situation. With an echo charger installed on the starter bank, this bank receives a charge from a small dedicated charger only when this small unit detects that the main house bank is being charged. The two arrangements are obviously slightly different but why is the echo charger arrangement better? Is it because the echo charger setup will not allow the house bank to draw down the charge in the starter battery.....or?

Also am I right in saying that the echo charger is a dumb unit and spits out the same voltage no matter what the charge rate is to the main batteries? If so, would an echo charger setup prevent a routine equalization operation from having any beneficial impact on the starter battery?

 

[sailingdog]

Neil—

The battery combiner is just a smart relay that combines the two banks in parallel when it senses a charging level voltage on one side. This is relatively simple but can result in your starting bank being "killed" by a very low house bank under certain conditions. However, this allows charging on the starting bank to charge the house bank or vice versa.

Also, as you pointed out, the battery combiner will not adjust the voltage for the starting battery's charge state, spitting out the same voltage that the house side requires. This can result in the starting side being overcharged.

The echo charger is a charger that uses a DC source rather than an AC source, and basically has similar sensing circuitry to the battery combiner and it activates when it senses a charging level voltage on the house bank side. However, this is a unidirectional device. It can only charge the starting bank—which is why it is important to have all the charging sources connected to the house bank when using one.

I hope this helps.

 

[Neil McDonald]

Thanks Sailingdog. So the optimum way to install an echo charger is with a selector switch that allows the two batteries to be combined under emergency conditions or when both battery banks need periodic equalization?

 

[Bill Roosa]

Battery combiner vs echo

I believe your Xantrex charger comes with 3 +12 volt output cables. Just running one to the starter battery will take care of your shore power charging issues.

What are you trying to accomplish with either of these devices? What is the problem?


I'm not sure why you would want a battery combiner or an echo charger.
A battery combiner has 3 terminals; input, bat 1, and bat 2. It acts like an automatic 3 way switch. It is designed to be used with an alternator not a shore power charger. Once the alternator voltage comes up the combiner allows the start battery to syphon off (at a 1.5 volt lower voltage BTW) current. When the alternator voltage drops below the a threshold level it separates the two banks. It charges you either 1.7 or 1.5 volts to do this automatically. Better to just have a manual 3-way and pay attention to the boat IMHO as combiners tend to leave one of your battery banks undercharged.

Chargers come with multiple output cables so you can attach them to separate banks.

I'm not familiar with the echo but it sounds like just a diode ($3 at digiKey) you connect between the two banks. These work with any charge device attached to the one battery bank. They keep one bank (+ diode lead) 1.5ish volts above the other (- diode lead).

Once again a 3 way switch will do all this for you and not leave you high and dry when it fails and gives no warning.

 

[Bill Roosa]

After a re-read

Combiners and the echo unit will not connect your battery banks together.
They only "combine" the batteries in the charge mode. You cannot get your start battery to drive house loads or house bank to drive the starter.
These types of setups are designed for systems that have separate start and house systems. You HAVE to use the start battery for starting and house battery for house loads. Just a SPST switch will connect your two systems and give you some redundancy.

How are your house and start batteries getting charged when the engine is on?

 

[Maine Sail]

. You HAVE to use the start battery for starting and house battery for house loads.

Bill this totally depends on how your system is wired.... I start on my house bank 100% of the time...

 

[sailingdog]

Bill—

First, battery combiners, like the Blue Sea ACR, do in fact combine the batteries, but only when it senses a charging level voltage. The earlier models only sensed charging voltages on one side without an additional wire run, the newer ones can detect it on either. They don't cause a voltage drop, since they are a relay, and not diode based—you're thinking of a battery isolator. They also work just fine with any charging source—wind, solar, alternators, and shore-power based AC chargers.

Echo chargers are a bit more sophisticated than a bunch of diodes.

The advantage of using an echo charger or battery combiner is that any charging source connected to the house bank will be able to charge BOTH banks without user intervention. Using the leads on the Xantrex is fine, when you have shorepower, but doesn't do anything for other charging sources, like wind, solar, and alternators.

Neil—

Yes, that would be fine.

 

[Don S/V ILLusion]

To go back to the original question, unless you routinely charge off your alternator for prolonged periods, you don't need to be concerned with this. As Bill already said in the first sentence of his first reply, your charger already compensates for the differing charge states of your batteries.

I believe your Xantrex charger comes with 3 +12 volt output cables. Just running one to the starter battery will take care of your shore power charging issues.

 

[Chuckbear]

Neil, Here is the set up we use, which is similar but different from yours.
http://trawler-beach-house.blogspot.... Batteries and Battery Chargers For The boat
Your AC charging is taken care of so not an issue. The echo charger is a good option to charge off your alternator but not so good if your AC charger is running most of the time on both house and start batteries. A combiner will not do it either under those circumstances. Either will do the job quite well when running the engine with the alternator charging the house bank with say, an echo charger handling the starting battery. Put a switch in line on the echo charger or combiner, which ever you choose, and turn it off when using shore power. Simple and inexpensive solution.

 

[Chuckbear]

Neal, Just another .02 from a different perspective. Consider getting rid of your start battery and adding an additional pair to your house bank. You really don't need a starting battery for your engine. Put them on a 1 or 2 switch to isolate one pair if you feel better. then charge the house bank with the alternator and nothing else is needed and it simplifies the entire system.

 

[Stu Jackson]

The "preferred" electrical system

routes the alternator output to the house bank and the reserve emergency backup (not "start") bank gets charged via either a combiner, echo charger, oil pressure relay or manual switch.

The ONLY difference between a combiner and an echo charger (and ACRs) is that the echo charger (and ACR) is a current limiting device. The advantage is that the EC limits the current flowing to the emergency bank to avoid overcharging, compared to a combiner which doesn't limit current and can, theoretically overcharge a full emergency bank. The reason is that when charging the drained house bank is controlling the charge which will want to be a lot more for the house bank than the emergency bank will ever need. In order to avoid that, we put a shutoff toggle switch in the ground wire from our combiner (which the instructions say is just he thing to do).

Both combiners and ECs are simple relays, only difference is one limits the current.

Maine Sail is right in that how you have your system wired is important. If you have a C or EC, then your shorepower output should be limited to one, just like your alternator output, and go to the house bank, even if you have multiple shorepower charger outputs.

Try this for more info: http://c34.org/bbs/index.php/topic,4623.0.html

I suggest reading the links in that thread, too.
http://c34.org/bbs/index.php/topic,4623.0.html

 

[Neil McDonald]

.... your charger already compensates for the differing charge states of your batteries.

Yes collectively but not independently. The more sophisticated chargers do independently regulate voltage to each bank depending on the state of charge. However the Truecharge 40 outputs "are not independently voltage regulated so it is important to avoid systems with mixed types of batteries." (Quote from the manual).

Having said this I am still contemplating replacing the wet cell starter battery with a low maintenance AGM (House batteries are wet cell). This is because the unit is located in a very difficult to access for maintenance position and several people have convinced me that the difference in optimum charging voltages between an AGM and wet cell can be ignored. Now if there was an echo charger on the market with an AGM voltage setting, then everything would be perfect!

 

[Don S/V ILLusion]

Neil
There must be two different Truecharge 40s - I think one is designated "plus" which is the one to which I refer as it (mine) does indeed regulate voltage independently. In this case, overcharging the start battery is not a problem. The evidence is apparent in the disparate voltage readings on the remote panel indicating different voltage of each bank.

If your charger does not do that,it must be a different version than mine.

 

[Stu Jackson]

Combiners and the echo unit(s)...only "combine" the batteries in the charge mode. You cannot get your start battery to drive house loads or house bank to drive the starter.
These types of setups are designed for systems that have separate start and house systems. You HAVE to use the start battery for starting and house battery for house loads. Just a SPST switch will connect your two systems and give you some redundancy. How are your house and start batteries getting charged when the engine is on?

Bill, WADR, that's simply just not true. If you read the link and review my wiring diagram in my previous post #11 above, you'll see I did just that with the old 1-2-B switch.

Also, the worst thing people can do is gang their two banks together when one is low. Either or, but not both should be the design. That's why I think the Dual Circuit Switch is a horrible concept. See the link I posted in #11 above.

 

[Stu Jackson]

Don't listen to the dockmates!!! Thy're wrong!

Having said this I am still contemplating replacing the wet cell starter battery with a low maintenance AGM (House batteries are wet cell). This is because the unit is located in a very difficult to access for maintenance position and several people have convinced me that the difference in optimum charging voltages between an AGM and wet cell can be ignored. Now if there was an echo charger on the market with an AGM voltage setting, then everything would be perfect!

Neil, you need to do some of your own research and not depend on the "several people have convinced me" approach.

The answer to your question is that you CANNOT do this BECAUSE the charging regimens for wet cells and AGMs are vastly different. THAT'S why you can't do it, not because your battery is hard to get to. If that was the case, why not just hide 'em all and charge away and kill your entirely new battery investment???

For some FACTS, read the Balmar Max Charge 612 regulator manual here: http://www.balmar.net/PDF/2005-mc-612-manual.pdf; page 9 of 17 of the PDF, chart with all voltage requirements at the bottom of the page.

You could by an Optima which would match. Ya wanna kill your AGM right away? Go right ahead.

You could also get a Duo Charge which would allow you to mix battery types. Read about that on the Balmar website. A Duo Charge is simply a combiner that allows mixing battery types, that's all.

So before you go burning up your new investment, do some reading. The www.balmar.net website has lots of good charging info.

Also read the Ample Power Primer, www.amplepower.com, Technical Documents tab.

Tell your friends they're not quite there...easy for them to use up your $$.

 

[Ron20324]

And do not run your engine when the shore-powered charger is working.

 

[Chuckbear]

And do not run your engine when the shore-powered charger is working.

Why would that be a problem? We run the engine all the time at the dock with the battery charger on and have done the same with many boats with no ill affects.

 

[Ron20324]

Why would that be a problem? We run the engine all the time at the dock with the battery charger on and have done the same with many boats with no ill affects.

Other than the fact that the owner's manual says, " WARNING! DO NOT OPERATE THE CHARGER WHEN THE ENGINE IS RUNNING" (ALL CAPS), I would think the voltage put out by the alternator might make the charger think that it is seeing battery voltage- which it is not- and adjust accordingly. Also, a high voltage from one source driven into the other might burn something out (diode, or whatever).

 

[Neil McDonald]

There must be two different Truecharge 40s - I think one is designated "plus" which is the one to which I refer as it (mine) does indeed regulate voltage independently. In this case, overcharging the start battery is not a problem. The evidence is apparent in the disparate voltage readings on the remote panel indicating different voltage of each bank. If your charger does not do that, it must be a different version than mine.

I checked the Xantrex website and they only have the 40+.... which is in fact what I have installed. My mistake. I suspect that the remote panel that you are refering to is a battery monitor that is wired quite independently from your charger, so the fact that it is showing a different voltage is not proof that your charger has separate regulators for each bank. In my case both banks are charged from only one of the three sets of Xantrex terminals (wiring by previous owner) so I KNOW that it can not discriminate between two battery banks.:naughty:

However I will give Xantrex a call on Monday about whether the Truecharge 40+ can independently regulate more than one battery bank - their head office is just down the road from here in Vancouver, another good Canadian company, and will post their response

You could by an Optima which would match.

Thanks Stu. As a matter of fact it was the Optima salesman at the local boat show that said an Optima could accept wet cell charging voltages. Maybe this is not classified as an AGM! This may be exactly what I need! Thanks also for the reading list - I will follow up. As for not listening to other peoples opinions - isn't this what this site is all about?

 

[Stu Jackson]

Comments on Neil's replies

I suspect that the remote panel that you are refering to is a battery monitor that is wired quite independently from your charger, so the fact that it is showing a different voltage is not proof that your charger has separate regulators for each bank. In my case both banks are charged from only one of the three sets of Xantrex terminals (wiring by previous owner) so I KNOW that it can not discriminate between two battery banks.

The TrueCharge units used to come with a remote panel. All the remote panels said was a mimic of the panel right on the unit. If it was showing actual voltage, digital, it was a battery monitor, a completely different animal.

However I will give Xantrex a call on Monday about whether the Truecharge 40+ can independently regulate more than one battery bank - their head office is just down the road from here in Vancouver, another good Canadian company, and will post their response

They can't, never could. The way they work, once past the bulk charge state, is essentially based on battery acceptance. See: http://c34.org/bbs/index.php/topic,4787.0.html Batteries that are full, like an emergency reserve bank, can get overcharged due to repeated bulk/acceptance stages or extended engine running when charging sources are being controlled by the depleted house banks. You may also be interested in this: http://c34.org/bbs/index.php/topic,4352.0.html

As a matter of fact it was the Optima salesman at the local boat show that said an Optima could accept wet cell charging voltages. Maybe this is not classified as an AGM! This may be exactly what I need! Thanks also for the reading list - I will follow up. As for not listening to other peoples opinions - isn't this what this site is all about?

Then he's dumb.:naughty: AGMs and Optimas are two different types of batteries. See the West Marine Advisors, like this http://www.westmarine.com/webapp/wcs/stores/servlet/westadvisor/10001/-1/10001/BatteryCharging.htm and http://www.westmarine.com/webapp/wc...1/-1/10001/SelectingaMarineStorageBattery.htm. See also: http://www.catalina-capri-25s.org/forum/topic.asp?TOPIC_ID=19287

Opinions: please remember I asked you to check FACTS, not only my opinions or those of others on this thread which I've noted may not be quite correct. That's why I provide links to reputable sources. Yes, some of them I've written (which could make them less than reputable ) but are based on the facts that I've learned from those very sources and culled them into simple English as much as I could after 25 years of boating electrical experience. Believe me or not, your choice, but when you do your homework let me know how far off we were.

You would also do well in searching on this board for echo chargers, combiners and alternators, since many of us have written about this in great detail earlier and there is a wealth of information right at your fingertips. You have some very good basic questions that may become clearer to you as you dig into the references and wiring diagrams.