Battery chargers

[Omatako]

There is another similar thread running but I didn't want to hi-jack it so here we go again.

I have a Xantrex smart charger powered off shorepower. It's a neat piece of kit capable of managing 3 banks in 3 distinctly different charge regimes and also properly manages up to 3 different battery types (wet cell, gel, AGM, whatever). It not only charges the assorted batteries in the boat but to also runs the inverter when appropriate without taking energy from the battery banks (don't ask me why I need this ). It works fine so problem. This the charger and I have the 50A 12V unit.

XC Battery Chargers - 12V & 24V

What I need now is a charge controller that can make the same sense out of my two alternators when I'm away from shore power.

Any recommendations that won't scare my bank manager (the one above did)?

Andre

[sailingdog]

Is this Xantrex a charger or a charger/inverter? If it is a charger, it can't run the inverter... If it is a charger/inverter, how can it supply energy to the inverter side without taking it from the batteries, unless you're plugged into shorepower.

What you need is two separate charge controllers, since you can't have one for both alternators IMHO, without causing yourself some problems. How large are the alternators?? Are the connected to two different battery banks? Are any of the banks connected to a battery combiner or echo charger???

Originally Posted by Omatako

There is another similar thread running but I didn't want to hi-jack it so here we go again.

I have a Xantrex smart charger powered off shorepower. It's a neat piece of kit capable of managing 3 banks in 3 distinctly different charge regimes and also properly manages up to 3 different battery types (wet cell, gel, AGM, whatever). It not only charges the assorted batteries in the boat but to also runs the inverter when appropriate without taking energy from the battery banks (don't ask me why I need this ). It works fine so problem. This the charger and I have the 50A 12V unit.

XC Battery Chargers - 12V & 24V

What I need now is a charge controller that can make the same sense out of my two alternators when I'm away from shore power.

Any recommendations that won't scare my bank manager (the one above did)?

Andre

[Omatako]

Originally Posted by sailingdog

Is this Xantrex a charger or a charger/inverter? If it is a charger, it can't run the inverter...

I have turned my notebook away from the charger so that it can't read this thread (it is really clever). It has been working OK for 4 months now and I don't want it to find out that it can't

It is a charger, not a charger/inverter and despite contrary opinion, it does run an inverter. In fact the inverter it runs is a Xantrex Freedom 25. Why don't I run the inverter/charger directly off mains? Because it's a 110V, 60hz unit and I'm on 220v 50hz supply.

The charger has the ability to put out a constant 50 amps. When the batteries are fully charged and the inverter calls for power (an appliance is switched on), the power drawn by the inverter comes directly from the charger.

How do I know this? I have a Xantrex Link 20 battery monitoring system that shows no draw from the batteries and the display panel of the charger tells me how much current is being drawn by the inverter.

The Xantrex dealer tells me that only if the draw from the inverter exceeds 50 amps (not done that yet) will it draw the excess from the battery bank. Naturally, if the charger is not providing any juice, all of the draw comes from the batteries.

Moving on . . .

My alternators are 85 amps, engine mounted and 160 amps, mounted on a seperate bracket off the front of the engine. As far as I know, they charge the starter and windlass batteries and directly into the house bank respectively.

What do you mean by a battery combiner (a 1-ALL-2 switch?) and WTH is an echo charger?

Andre

[sailingdog]

AHh... so it is a 220 V charger, plugged into 220 VAC shorepower that is running the inverter via the DC side... That makes sense now.. I take it that the boat is wired for 110 VAC, since this boat was bought in the USA IIRC.

A battery combiner is a device, like the BlueSea ACR that has a voltage sensor and a relay and will connect the two different banks in parallel when it senses a charging level voltage on either bank. This way, you can charge both banks off of a single charging source without having to turn the battery switch to the BOTH position.

IIRC, an echo charger is a circuit or device that will charge a second battery bank once the battery bank that the charger is attached to is topped up. Does much the same as the battery combiner, but lets the primary battery bank charge a bit more in the process.


Xantrex's Freedom inverter/charger series often have an echo charger built into them, so that they can charge two separate battery banks, with the primary bank being the larger house bank generally. This is important, since the larger house bank takes much longer to charge than the smaller starting bank generally does.

Are the two alternators voltage regulated internally? If so, why do you need a charge controller? If not, you'll want a good external charge controller that can do a three-stage intelligent battery charge.

Something like THIS would probably do the trick.

[camaraderie]

Andre...your alternators must have some regulation on them now. Are they internally regulated?
Also can you spell out the size quantity and type of battery you have for starter, windlass and house bank AND if any of those banks are wired for 24V operation. (Often a windlass is.)

BTW...here is the echo charger but it does not sound like you need one since you are already set up to charge both banks. It is very useful when you have a single house bank and want to charge the starting battery when the house bank is "full".

[Omatako]

Originally Posted by sailingdog

AHh... so it is a 220 V charger, plugged into 220 VAC shorepower that is running the inverter via the DC side... That makes sense now.. I take it that the boat is wired for 110 VAC, since this boat was bought in the USA IIRC.

You have a good memory, yes my AC systems are largely 110v although I have started to integrate them with 220v.

This looks good and you can't fight about the price . I'll have a closer look at this.

Model	Type	Price
BA-RG-MC-612	Max Charge Regulator 12V	$00.00
BA-RG-MC-612-H	Max Charge Regulator 12V w/har	$00.00
BA-RG-MC-624	Max Charge Regulator 24V	$00.00
BA-RG-MC-624-H	Max Charge Regulator 24V w/har	$00.00
BA-RG-MC-632	Max Charge Regulator 32V	$00.00
BA-RG-MC-632-H	Max Charge Regulator 32V w/har	$00.00

Originally Posted by sailingdog

Are the two alternators voltage regulated internally? If so, why do you need a charge controller?

Yes they are and that is where I believe I'll have problem at sea when I have to depend on the alts for charging. AFAIK the in-built regs do a fast charge up to 85% of capacity and then they go onto a float charge that takes forever to put in the other 15%.

Cam, I have a house bank of 4 Tojan 105's, the starter and windlass batteries are both lead acid 110Ah 12V. The windlass battery is connected to the system only by way of a charge line and a heat-sensitive isolator in the line, i.e. there are no big cables running for'ard.

I understand from other sources that if I want to put in a charge controller, I have to isolate the internal regulators. I also understand that there is a way to isolate the excitation current to the stator windings to effectively "switch off" an alternator. Any info on this would be useful because I reckon one of my answers is to switch off one alternator until it is needed. But then I'd need an echo charger (new concept to me).

Thanks for the info so far.

Andre

PS - one of my problems with 2 alts is that the ampmeter that monitors their performance reads both incoming currents together so I have no way of knowing if either one has stopped working. This happened when we sailed from the US, when an alernator stopped charging, I flicked the 1-ALL-2 switch to bring the other alt on line to the house bank to find that it was already not working!!!

[sailingdog]

Omatako-

All smart chargers, even those in smart voltage regulators, will take a fairly long time to go from the point where bulk charging stops and the absorbtion and float phases end. An external regulator probably won't speed this up much.

A good way to solve the problem is to use the alternators to do the bulk phase charging and to use an alternative source for the float and absorption phases, like a wind gen or solar panels.

An battery combiner or echo charger would be one way to deal with it. Do you have three separate banks--start, windlass and house, or are the starter/windlass both on the same bank. From your description above, it sounds like you actually have three banks. What might make sense is to have the house bank separate, and windlass bank echo charge the start bank (or vice versa).

[Omatako]

SD - from a charge perspective the start and windlass are on the same bank because they are interconnected to the same alternator.

They are seperate inasmuch as the windlass battery only powers the windlass, there are no HD cables coming back to the rest of the system. If the start battery were to be flat and an attempt to start would be made, the high demand required would be requested from the windlass battery down the charge lines hence the temp-sensitive coupling which then takes the windlass battery temporarily out of the circuit (it re-estalishes the circuit when it cools down). Does that make sense?

The start battery can be brought into the house bank a vice versa with the 1-ALL-2 switch but this would not include the windlass battery.

The Link 20 battery manager recognises only two banks and by process of elimination I determined that the start and windlass are seen as one and the same. I reckon in this sitution, an echo charger as you recommend is probably the best choice.

As far as the charge rate is concerned, the Xantrex mains charger that I have has temp sensors on each battery and will charge at a full bulk rate until 95% of capacity unless any one of the batteries gets too warm. Then it will shake out only that battery bank and continue charging the rest. I suppose I was hoping achieve this with a charge manager of some sort on the alternators.

Andre

[sailingdog]

Personally, I would disconnect the "charge" cables that are going to the windlass battery and leave the windlass battery connected to either a battery combiner or echo charger output. This will prevent the windlass from trying to draw from the start battery or the starter from trying to draw from the windlass battery, but still provide you a way to charge the windlass battery. This would effectively leave you with THREE separate banks, which probably makes the most sense, given the information you have provided.

[tjaldur]

On my ship the distance between the charger/batteribanks and the windlass is about 10 meters. So my solution is to store the batteries to the windlass together with the windlass. Thus the cables from the battery to the windlass are only a foot long. In the box, under the windlass where the batteries are stored, I also store a separate 18 amp/220 volts charger. The 1500 watt (pure sinus) inverter delivers the current to this charger. With this arrangement the current is transported from the inverter to the charger of the windlass batteries in 220 volts, and the cables are accordingly the standard for transporting 10 amp (in 220 volts, 1,5 mm2)