I was thinking about adding a battery combiner to my boat's electrical
system, but I may have to rethink this.

Present System
------------------
Bank 1 - Starting battery
Bank 2 - House - 2x6V Trojans (225AH)
Shore power charger - 2 bank Truecharge 10 charger connected direct to
batteries with fused leads
Alternator - 55Amp on Yanmar 2QM15.

Presently, my alternator charges back via the starter motor cable. It leads
to the common terminal of the "red" 1-2-All switch. The batteries are
connected to the other two terminals in the usual way. So, I can chose to
charge either battery or both. House load also connects to common terminal
but also has it's own breaker switch.

1. Using Combiner
----------------------
I have looked at using the New Zealand made BEP VSR (Voltage Sensitive
Relay) as the combiner. But, in reading their website, they warn against
using such devices if the alternator and batteries are not matched. They say
that for the combiner to work, the alternator must be larger (80-90A) or the
batteries smaller (100-130AH). Otherwise, the unit will oscillate and not
work properly.
http://www.bepmarine.com/showproduct.cfm?productid=12
http://www.bepmarine.com/products/inst-710-100a-vsr(web).pdf

Another supplier - Sure Power talks of same problem but says that time delay
avoids chattering - But they don't provide details - Perhaps if alternator
is connected to house battery, it may work better?
http://www.surepower.com/separator.html

West Marine do not mention this problem in my older catalogue.

2. Echo-Charge
-------------------
Another possibility is to use a Xantrex Echo-Charge.
http://www.xantrex.com/web/id/103/p/.../5/product.asp

Seems alternator is connected to House bank. Then when voltage reaches 13v
this unit actuates and then charges starting battery. No mention of cycling
with undersize alternator. When unit kicks in, wouldn't voltage likely drop?

3. Diode isolator
--------------------
Would work, but voltage drop would likely reduce battery capacity and life.

4. Manual switching
-------------------------
That's what we do now! We have zap-Stop to protect alternator. But, it is
easy to forget to switch the batteries.

5. New Alternator
---------------------
Installing a larger alternator (say 120A) would be an option, but with
single belt and a real HP output of less than 10HP at normal rpm, this could
diminish engine output and perhaps put loads on engine that 'it's not
designed for. (The 55A is the optional alt. - normal is 35A!). Seems
overkill just to allow easier switching, but this would allow quicker
recharging of house batteries.

6. Portable Generator
--------------------------
This has passed my mind - Use a portable Honda to charge the house
batteries. But at 10A, this would require a long run!

Ideas, comments or condolences welcomed

GM

My current boat has two Optima starting bats plus a house bank with 4
6v Trojan T105's. Charging is with Xantrex 100 Amp, and a high output
alternator plus solar panels. The factory setup was a large 3 bank
combiner. I had to modify it when I added the high output alternator
because the alternator output had to feed the house bank, not a
starter battery, or else the regulator sensing gets very confused
(which can lead to a meltdown!).

Although the system works, I never like the "all or nothing" aspect of
the combiner, and occasionally it would cycle on and off for no
apparent reason. Finally I got an EchoCharge for about $100 and use
that to charge the starting bats, which are still on the combiner.
I've found no downside (so far) to this setup. The starting batteries
get an appropriate trickle charge whenever a charge source is
available, and everything is disconnected otherwise. The starting
batteries virtually never present a large load, so there is no
noticeable "kick in" of the EchoCharge.

I don't like the diode isolator solution, because of the voltage drop
which means you have to raise the voltage in the regulator to
compensate. And it seems you're just converting some of your juice to
heat. As for adding a "120 Amp alternator," your battery bank will
not accept that much power. Even with a smart regulator, it would
only accept about 50 Amps. On the other hand, your 55 Amp Yanmar
(actually probably Hitachi) alternator probably only puts out about
25-30 Amps, because it has a simple built in regulator. The new
alternator would want a smart regulator, so this is adding up to a
serious upgrade - if you want thoughtful advice on this you'll have to
tell us want you plan to power with this!

The Honda generator is not a bad way to go, I've been on the verge of
getting one for a few years. The output is much higher than 10 Amps,
because you can feed the AC output into your battery charger. Several
threads here discuss the efficiency losses. My problem is that I'm
not likely to equal the 100 Amps my alternator puts out, but if I had
a smaller system, this would be an attractive alternative. Most of
my sisterships (PDQ 36) have outboards rather than diesels, and many
use a Honda 2000 for charging.






GBM wrote:
I was thinking about adding a battery combiner to my boat's electrical
system, but I may have to rethink this.

Present System
------------------
Bank 1 - Starting battery
Bank 2 - House - 2x6V Trojans (225AH)
Shore power charger - 2 bank Truecharge 10 charger connected direct to
batteries with fused leads
Alternator - 55Amp on Yanmar 2QM15.

Presently, my alternator charges back via the starter motor cable. It leads
to the common terminal of the "red" 1-2-All switch. The batteries are
connected to the other two terminals in the usual way. So, I can chose to
charge either battery or both. House load also connects to common terminal
but also has it's own breaker switch.

1. Using Combiner
----------------------
I have looked at using the New Zealand made BEP VSR (Voltage Sensitive
Relay) as the combiner. But, in reading their website, they warn against
using such devices if the alternator and batteries are not matched. They say
that for the combiner to work, the alternator must be larger (80-90A) or the
batteries smaller (100-130AH). Otherwise, the unit will oscillate and not
work properly.
http://www.bepmarine.com/showproduct.cfm?productid=12
http://www.bepmarine.com/products/inst-710-100a-vsr(web).pdf

Another supplier - Sure Power talks of same problem but says that time delay
avoids chattering - But they don't provide details - Perhaps if alternator
is connected to house battery, it may work better?
http://www.surepower.com/separator.html

West Marine do not mention this problem in my older catalogue.

2. Echo-Charge
-------------------
Another possibility is to use a Xantrex Echo-Charge.
http://www.xantrex.com/web/id/103/p/.../5/product.asp

Seems alternator is connected to House bank. Then when voltage reaches 13v
this unit actuates and then charges starting battery. No mention of cycling
with undersize alternator. When unit kicks in, wouldn't voltage likely drop?

3. Diode isolator
--------------------
Would work, but voltage drop would likely reduce battery capacity and life.

4. Manual switching
-------------------------
That's what we do now! We have zap-Stop to protect alternator. But, it is
easy to forget to switch the batteries.

5. New Alternator
---------------------
Installing a larger alternator (say 120A) would be an option, but with
single belt and a real HP output of less than 10HP at normal rpm, this could
diminish engine output and perhaps put loads on engine that 'it's not
designed for. (The 55A is the optional alt. - normal is 35A!). Seems
overkill just to allow easier switching, but this would allow quicker
recharging of house batteries.

6. Portable Generator
--------------------------
This has passed my mind - Use a portable Honda to charge the house
batteries. But at 10A, this would require a long run!

Ideas, comments or condolences welcomed

GM

"Jeff" wrote in message
...

Finally I got an EchoCharge for about $100

The starting batteries get an appropriate trickle charge whenever a
charge source is
available, and everything is disconnected otherwise. The starting
batteries virtually never present a large load, so there is no
noticeable "kick in" of the EchoCharge.

So perhaps this would work in my case? If my house bank gets up to 13v
before this kicks in, and starting battery is at 12v or less, hopefully with
my small alternator, voltage does not drop below 13v causing cycling?


I don't like the diode isolator solution, because of the voltage drop
which means you have to raise the voltage in the regulator to
compensate. And it seems you're just converting some of your juice to
heat.

Yes, this is least attractive good option.

As for adding a "120 Amp alternator," your battery bank will
not accept that much power. Even with a smart regulator, it would
only accept about 50 Amps. On the other hand, your 55 Amp Yanmar
(actually probably Hitachi) alternator probably only puts out about
25-30 Amps, because it has a simple built in regulator. The new
alternator would want a smart regulator, so this is adding up to a
serious upgrade - if you want thoughtful advice on this you'll have to
tell us want you plan to power with this!

Presently, the boat (32 foot sail) would be used for short cruises - maybe
up to a week long. It will have new refrigeration that will draw 4 amps when
running and hopefully no more than 40AH per day. Other loads are lights,
radios, instruments, Autohelm (seldom used), windlass (not presently
connected). I expect I will have to run engine for a couple of hours per day
or get back to shore power.


The Honda generator is not a bad way to go, I've been on the verge of
getting one for a few years. The output is much higher than 10 Amps,
because you can feed the AC output into your battery charger.

I would like to get one too. I could probably sell the idea to the
"management" as a safety item for home power back up next time we have an
ice-storm or other unforeseen power outage. On the boat, our engine does
not have a heat exchanger, and I have considered this as a way of producing
hot water - Run the generator for a while - charge the batteries and heat
the hot water. A bit of an expensive solution, but a nice-to-have!

Thanks for the input

GM



GBM wrote:
I was thinking about adding a battery combiner to my boat's electrical
system, but I may have to rethink this.

Present System
------------------
Bank 1 - Starting battery
Bank 2 - House - 2x6V Trojans (225AH)
Shore power charger - 2 bank Truecharge 10 charger connected direct to
batteries with fused leads
Alternator - 55Amp on Yanmar 2QM15.

Presently, my alternator charges back via the starter motor cable. It
leads
to the common terminal of the "red" 1-2-All switch. The batteries are
connected to the other two terminals in the usual way. So, I can chose
to
charge either battery or both. House load also connects to common
terminal
but also has it's own breaker switch.

1. Using Combiner
----------------------
I have looked at using the New Zealand made BEP VSR (Voltage Sensitive
Relay) as the combiner. But, in reading their website, they warn against
using such devices if the alternator and batteries are not matched. They
say
that for the combiner to work, the alternator must be larger (80-90A) or
the
batteries smaller (100-130AH). Otherwise, the unit will oscillate and
not
work properly.
http://www.bepmarine.com/showproduct.cfm?productid=12
http://www.bepmarine.com/products/inst-710-100a-vsr(web).pdf

Another supplier - Sure Power talks of same problem but says that time
delay
avoids chattering - But they don't provide details - Perhaps if
alternator
is connected to house battery, it may work better?
http://www.surepower.com/separator.html

West Marine do not mention this problem in my older catalogue.

2. Echo-Charge
-------------------
Another possibility is to use a Xantrex Echo-Charge.
http://www.xantrex.com/web/id/103/p/.../5/product.asp

Seems alternator is connected to House bank. Then when voltage reaches
13v
this unit actuates and then charges starting battery. No mention of
cycling
with undersize alternator. When unit kicks in, wouldn't voltage likely
drop?

3. Diode isolator
--------------------
Would work, but voltage drop would likely reduce battery capacity and
life.

4. Manual switching
-------------------------
That's what we do now! We have zap-Stop to protect alternator. But, it
is
easy to forget to switch the batteries.

5. New Alternator
---------------------
Installing a larger alternator (say 120A) would be an option, but with
single belt and a real HP output of less than 10HP at normal rpm, this
could
diminish engine output and perhaps put loads on engine that 'it's not
designed for. (The 55A is the optional alt. - normal is 35A!). Seems
overkill just to allow easier switching, but this would allow quicker
recharging of house batteries.

6. Portable Generator
--------------------------
This has passed my mind - Use a portable Honda to charge the house
batteries. But at 10A, this would require a long run!

Ideas, comments or condolences welcomed

GM

We made the West Marine battery combiner for them for 13 years but now
are using Defender as our primary retailer - you will find Defender's
prices are much better than WM had. I don't know what is wrong with
other combiners but we've not had any of the problems you describe with
over 26,000 sold and all on UNCONDITIONAL warranty. If there were a
problem we surely would have heard something by now.

You can download the owner's manual from
http://www.yandina.com/acrobats/C150Data.pdf
and you will find a number of suggested schematics.

You can contact Defender at
http://www.defender.com/product.jsp?path=-1|328|51495|606044&id=605590

I will be happy to answer any questions you have.

Regards,

Andina Marie Foster,

GBM wrote:
"Jeff" wrote in message
...
Finally I got an EchoCharge for about $100
....

So perhaps this would work in my case? If my house bank gets up to 13v
before this kicks in, and starting battery is at 12v or less, hopefully with
my small alternator, voltage does not drop below 13v causing cycling?


The actual use for starting is about 60 amps times a few seconds, so
the starting battery is never discharged more than a few percent
(unless its been off a charger for a few weeks or more). While is may
use a significant portion of the alternator output for a few minutes,
it will quickly settle into a trickle charge mode.

... if you want thoughtful advice on this you'll have to
tell us want you plan to power with this!


Presently, the boat (32 foot sail) would be used for short cruises - maybe
up to a week long. It will have new refrigeration that will draw 4 amps when
running and hopefully no more than 40AH per day. Other loads are lights,
radios, instruments, Autohelm (seldom used), windlass (not presently
connected). I expect I will have to run engine for a couple of hours per day
or get back to shore power.

Our previous boat was similar to yours (2 6v batteries) and we had an
older Danfoss system. The load was about 50-65 AH per day, which took
about 1.5 hours to recharge. Even though we had a high output
alternator, the smaller bank limited the charge rate. The cheapest
thing we could have done, though not always the easiest thing on a
small boat, would be to add more battery storage. If you have a good
place to stash 2 more 6v bats, you could double capacity for under
$200. This would mean you could go 2-3 days without running the
engine, greatly increasing the chance you recharge in the normal
course of using the boat.

This is a frustrating issue, because the urge is to find a "proper"
solution, but that costs money. I would love to find a "half decent"
alternator/regulator that was under $500, or an amp-hour meter for
$50. The only thing that seems cheap are the batteries!



I would like to get one too. I could probably sell the idea to the
"management" as a safety item for home power back up next time we have an
ice-storm or other unforeseen power outage. On the boat, our engine does
not have a heat exchanger, and I have considered this as a way of producing
hot water - Run the generator for a while - charge the batteries and heat
the hot water. A bit of an expensive solution, but a nice-to-have!

For this I do have a solution: the black bag. My old boat even had a
propane hot water heater, but we preferred the black bag, especially
for summer vacations. This was even a way to conserve water and get
exercise, since I would row into the town dock to fill up one or two
black bags.

In my case, I have a relatively low output alternator (55A) charging two
battery banks. House consists of 2 6V golf cart batteries in series with
210AH capacity. The other is a conventional starting battery. If alternator
is charging House (which may be down to about 50% charge) and just reaches
13.3V, what happens when the combiner contacts close? Presumably it adds a
load to the alternator and the voltage drops a bit below 13.3v? Then,
wouldn't the combiner disconnect and keep repeating the cycle? The BEP site
warns against this and provides sizes of alternator/battery to prevent
cycling. Is there any built in protection against this in your unit?

Thanks for your interest,

GBM


"Andina Marie" wrote in message
oups.com...
We made the West Marine battery combiner for them for 13 years but now
are using Defender as our primary retailer - you will find Defender's
prices are much better than WM had. I don't know what is wrong with
other combiners but we've not had any of the problems you describe with
over 26,000 sold and all on UNCONDITIONAL warranty. If there were a
problem we surely would have heard something by now.

You can download the owner's manual from
http://www.yandina.com/acrobats/C150Data.pdf
and you will find a number of suggested schematics.

You can contact Defender at
http://www.defender.com/product.jsp?path=-1|328|51495|606044&id=605590

I will be happy to answer any questions you have.

Regards,

Andina Marie Foster,

"Jeff" wrote

This is a frustrating issue, because the urge is to find a "proper"
solution, but that costs money. I would love to find a "half decent"
alternator/regulator that was under $500, or an amp-hour meter for
$50. The only thing that seems cheap are the batteries!


In researching this, I came across what seems a reasonable solution made by
Blue Seas. It consists of their Batterylink and their Dual Circuit battery
switch

http://www.bluesea.com/Article_detai..._ID=137&id=273

Cost seems to be reasonable. Does this seem like a reasonable way to go?

GBM

I use something similar to the Bluesea - Smartbank split charge
controller - www.smartgauge.co.uk

GBM wrote:
"Jeff" wrote

This is a frustrating issue, because the urge is to find a "proper"
solution, but that costs money. I would love to find a "half decent"
alternator/regulator that was under $500, or an amp-hour meter for
$50. The only thing that seems cheap are the batteries!



In researching this, I came across what seems a reasonable solution made by
Blue Seas. It consists of their Batterylink and their Dual Circuit battery
switch

http://www.bluesea.com/Article_detai..._ID=137&id=273

Cost seems to be reasonable. Does this seem like a reasonable way to go?

GBM


It looks like a battery combiner. Its more expensive then some, but
with adjustable set points it is probably a reasonable value.

My personal preference is for an EchoCharge, which is only a few
dollars more. In fact, I was willing to buy one even though I already
had a combiner similar to the ACR. My issue is that I frequently
discharge my house bank and then spend an hour or more charging at
fairly high voltage. A combiner would be overcharging the starting
batteries during these times. The EchoCharge allows the starting
batteries to trickle charge, while the house bank getting 90 Amps.

"Jeff" wrote

My personal preference is for an EchoCharge, which is only a few
dollars more. In fact, I was willing to buy one even though I already
had a combiner similar to the ACR. My issue is that I frequently
discharge my house bank and then spend an hour or more charging at
fairly high voltage. A combiner would be overcharging the starting
batteries during these times. The EchoCharge allows the starting
batteries to trickle charge, while the house bank getting 90 Amps.

Jeff,
If the combiner is set to close the contact at say 13.5v, my concern is that
with House at low level, this might not happen before I want to turn the
engine off, so the starting battery gets no charge at all! This would
presumably be true for Echo-Charge too.

Regarding the Echo-Charge vs ACR. In the case of the combiner, once the
contact closes, the alternator "sees" both batteries. Wouldn't the current
flow distribute itself where needed? I have read that the current to the
starting battery should be limited by the wire gauge used. I think I read
that oversizing the connections can cause problems such as too high a
current flow through the combiner. In the case of the Echo-Charge, how does
it "control" the current flow? Is it just a resistor?

GBM