Echo charging my start battery...

[Boracay]

I've brought an Xantrex Echo Charger and want to wire it up so that it charges my house batteries first and my start battery second.

I'm planning to wire the alternator directly to the house circuit buses, with the Echo Charger wired onto the alternator (see diagram 1).

Xantrex wants the echo charge to come off the house batteries (see diagram 2).

I don't want to ground everything as Boracay is steel and I'm trying to keep stray electrons down.

Can anyone see any problems with how I'm proposing to install the Echo Charger?

Sorry about the mud map quality.

[Christian Van H]

Whoa. Now you've lost me. The EchoCharge is designed to keep your starting battery topped up FROM your house banks. It senses a charging voltage when your house banks are fed from your alternator or windgen / solar cells. Not sure why you would use it any other way...

[Boracay]

The differences in terms of wiring are:-
1) Instead of connecting to echo charger to the house batteries I am proposing to connect it to the alternator (other end of the wires). Almost exactly the same voltage (provided I use heavy wires) just different position.
Do I need to run cabling from the house batteries back to the echo charger, or should I be connecting it close to the house batteries.?
2) I am also proposing to connect to the house side of the master switches so that as the engine runs the house circuits become live, even if the master switches are off. I want to know if this would cause problems.

Is there a better way to do this?

[Trekka]

It reads to me that you are taking a simple solution and making it complex.

What battery do you want your alternator regulator sensing?
I think it is the house bank. So wire the alternator to the house bank.
Then wire the echo charger from house bank to starter battery.
The house bank will get as much current as it needs for as long as it needs. And the echo charger will provide up to 15a to the starter battery as needed. Simple. Done.

Your additional plan to bypass the master power switch is a bad idea. It is there for a reason. Use it. If you want house power while the engine is running turn it on, if not turn it off. Don't take that power of choice and your control away from yourself.

Keep the simple tried and true, simple. It is for a reason.

[cal40john]

I don't see any reason why you can't connect the Echo to the alternator. As you said, given a sufficiently large conductor, any point you connect to on the wire is the same.

I think you want to contact Xantrex about the master switches. Since we don't know the circuitry of the Echo charger, which is more than a simple relay since it limits current flow to less than 15 amps, we don't know what voltage the sense input to your regulator will see through the Echo to the start battery with the house bank disconnected, which could cause the regulator to not perform correctly.

Also I doubt that the Echo charger is going to allow current to flow through it from the start battery to the house buss, so the house buss will be powered by the alternator essentially with the start battery disconnected from the house buss.

John

[Trekka]

He dosen't say that with the master switch off the house bank is disconnected from the alternator. He says, and drawing indicates, he wants to connect the house bank directly to the alternator. In addition he would connect house to master switch, but also a bypass of the master switch so the alternator feeds house buss directly, a very bad idea.

As for charging control, is he using an external regulator or internal? His diagrams suggest internal.

There is simply no valid reason to double connect to the alternator both the house bank - which will need a lot of current - and the echocharge/starter battery which will need minimal. Why get into a situation where the regulator - any regulator - has to look at them combined to decide what to do? If he wants them fed separately he could cable alternator to a combiner and the 2 outputs from there tyo each battery bank.

The standard way is sensible and simple. Look at the two drawings. The sensible way has minimal cabling, where the way he is thinking has much more - and doesn't have drawn in the additional cabling and circuits to bypass the master house buss switch. (which would be asking for trouble)

[cal40john]

Originally Posted by Trekka

He dosen't say that with the master switch off the house bank is disconnected from the alternator. He says, and drawing indicates, he wants to connect the house bank directly to the alternator. In addition he would connect house to master switch, but also a bypass of the master switch so the alternator feeds house buss directly, a very bad idea.

As for charging control, is he using an external regulator or internal? His diagrams suggest internal.

There is simply no valid reason to double connect to the alternator both the house bank - which will need a lot of current - and the echocharge/starter battery which will need minimal. Why get into a situation where the regulator - any regulator - has to look at them combined to decide what to do? If he wants them fed separately he could cable alternator to a combiner and the 2 outputs from there tyo each battery bank.

The standard way is sensible and simple. Look at the two drawings. The sensible way has minimal cabling, where the way he is thinking has much more - and doesn't have drawn in the additional cabling and circuits to bypass the master house buss switch. (which would be asking for trouble)

That's not how I read what he says. I don't think there is more wiring, I think he's trying to be able to either take a bad house bank out of the circuit and/or run the house loads off of the start battery without the house bank in the circuit if needed, which I don't think is going to work with the Echo charger.

Replace the Echo in his diagram with a relay which closes by turning on the ignition switch and you have how my boat is wired. (Except there are no ground disconnects on mine.)

I guess we need Boracay's clarification.

[Extemporaneous]

Allow me to flounder and guess.
On one hand I see a difference in the grounding location.
I also wonder if there was heavy charging going on and you through the master switch if the alternator could react and reduce output to just what the charger will take (15 amps) before blowing things up?

[Extemporaneous]

A little different but related. Also, I will take this elsewhere if you think it takes away from your question. I thought the Echo would be a good way to charge the starter battery which would or could be a different type i.e. flooded vs deep cycle until I seen this:


"Xantrex’ digital echo~charge (part#82-0123-01) is designed to charge auxiliary or starting batteries from an inverter/charger or other charging source with limited voltage drop. The Xantrex echo~charge detects when the house battery bank is being charged and directs a portion of the charge current to auxiliary or starting batteries. The maximum charger current offered by echo~charge is limited to 15 amps.
Product Features

• 15 A maximum charge current
• Automatically adjusts for 12 or 24 volt battery banks (both battery banks must be the same DC voltage and battery type)"

"must be the same DC voltage and battery type"

If one had an inverter would it make any sense to run a 120v charger from it and then you would at least be able to change the battery type on the charger to regular flooded?

Originally Posted by Boracay

I've brought an Xantrex Echo Charger and want to wire it up so that it charges my house batteries first and my start battery second.

I'm planning to wire the alternator directly to the house circuit buses, with the Echo Charger wired onto the alternator (see diagram 1).

Xantrex wants the echo charge to come off the house batteries (see diagram 2).

I don't want to ground everything as Boracay is steel and I'm trying to keep stray electrons down.

Can anyone see any problems with how I'm proposing to install the Echo Charger?

Sorry about the mud map quality.

[Boracay]

I'll take the point that wiring to the house buses is not a good idea.

Currently I'm thinking that switches on the cables from the alternator to the house bank are the way to go if I want to isolate the house bank from the steel hull. Just have to remember to close them before starting the engine.

I'm assuming that the alternator output will reduce as voltage rises, so if the switches on the connecting cables are open then the alternator voltage will increase and the current will reduce.

[Sandero]

This baffles me. You are trying to not have the echo circuit connected to ground but a separate neg buss because your fear corrosion from stray electrons?

Or you want to charge the start directly from the alternator?

What is the goal of this exercise?

I believe the idea of the echo charge is to isolate two somewhat dissimilar batteries of different sizes and charge requirements. The start bank needs lots of cranking power and is used only for brief spurts. The house banks is used "continuously" and requires more capacity. So the alternator is connected to the house bank which under normal use will require more charge to top them up. The echo charger then siphons off the excess charge and send it to the smaller start bank WHILE the alternator is on and WHILE other charging sources are on and even WHILE the house bank is on shore power of WHEN it simply is full up and can send some little charge over to the smaller start bank.

I nhave on echo installed and I have also altered the wiring of my key switch. What I discovered is that the power coming to the key switch is then used for the sarter solenoid AND the engine instruments, including lighting AND the ventilation for the engine compartment. So this circuit is under load and draining the battery WHILE motoring, NOT just for starting! I moved all loads EXCEPT the solenoid from the key switch and so the only drain is the starter motor and closing the solenoid.

I have found that my start bank is always 100% topped up. It an Optima blue top 55AH and the engine is a Volvo 36HP. Starts are no problem!

The house bank are 2 AGM 8Ds in parallel with 100 watts of solar trickle charge with a PV14 regulator. The alternator is a 120 amp output with a MaxCharge612. Either the house bank does not become deeply discharged or the regulator alternator system is off, but I rarely if ever see more than 40 amps output and only for a few minutes as it ramps down and settles float in the 5-10 amp range. I suppose I never get deeply discharged to demand oddles of charging for the house bank. And this may be because we use our engine at least an hour or more a day when on board for refrigeration (engine drive), making hot water (heat exchanger via engine) and shower and vacuum (AC loads) during this "charging period". When all is being done, we are showered, the boat is topped up, the hot water topped up, the batteries topped up, the refer cooled down. Now we use the windlass (engine on) to weigh anchor and motor out of the harbor to raise sail and revert to use of the house bank for electricity. When we are going to make landfall we use our topped up start bank to get the motor going and the alternator cranks out as many amps as required to replenish the used power of the sail.

This is simple and seems to work. Try it!