So my AC charger is a West Marine 5 amp. Alternator is a 60a which puts
out 35a. I (will) have two 6V T105s in series on BANK2 and a Kirkland
900cca starting battery on BANK1. I connect both charging sources to
BANK2 either on the battery switcher BANK2 post or right on the BANK2
batteries.

I can charge both banks at the same time by putting the switch on BOTH
and don't have to worry about the starting battery getting overcharged
because even if it is mostly charged and BANK2 is almost dead, both
banks will only get what charge they need on the BOTH setting?


--
Stephen

-------

For any proposition there is always some sufficiently narrow
interpretation of its terms, such that it turns out true, and
some sufficiently wide interpretation such that it turns out
false...concept stretching will refute *any* statement, and will
leave no true statement whatsoever.
-- Imre Lakatos

You are correct, you can charge them both at the same time in parallel.
If there is any voltage difference when you switch to "BOTH" current
will rapidly flow from the higher voltage one to the lower and they
will rapidly end up at the same voltage and then charge uniformly.

There is information on combiners at
http://www.yandina.com/combInfo.htm#Q2 that do this automatically.

Stephen Trapani wrote:
So my AC charger is a West Marine 5 amp. Alternator is a 60a which puts
out 35a. I (will) have two 6V T105s in series on BANK2 and a Kirkland
900cca starting battery on BANK1. I connect both charging sources to
BANK2 either on the battery switcher BANK2 post or right on the BANK2
batteries.

Remember that there is a connection between the alternator and the
starting motor on your Yanmar (I assuming that's what you have - I
don't know why). I'm guessing you want the alternator only on bank 2
and the starter only on bank 1.


I can charge both banks at the same time by putting the switch on BOTH
and don't have to worry about the starting battery getting overcharged
because even if it is mostly charged and BANK2 is almost dead, both
banks will only get what charge they need on the BOTH setting?

It could overcharge, but probably won't be that bad except in extreme
cases. The worst case is that your cheap Kirkland will only last 2 or
3 years. If you want to prevent this, you have to invest in something
like an EchoCharge, which is idiot proof, or figure out a fancier
switch setup, and remember to always do it right. When I was using a
combiner (which essentially sets it to "Both" when charging) the
starter bats still lasted 4 or 5 years. When I replaced them with
AGMs I added the EchoCharge.

Actually, your bigger problem may be that the stock Yanmar (Hitachi)
alternator won't do a great job of charging the house bank, so it
could end up chronically undercharged. I wouldn't worry now, but its
something to watch when you have it running.

Stephen Trapani wrote in news:IxjTf.91
:

So my AC charger is a West Marine 5 amp. Alternator is a 60a which puts
out 35a. I (will) have two 6V T105s in series on BANK2 and a Kirkland
900cca starting battery on BANK1. I connect both charging sources to
BANK2 either on the battery switcher BANK2 post or right on the BANK2
batteries.

I can charge both banks at the same time by putting the switch on BOTH
and don't have to worry about the starting battery getting overcharged
because even if it is mostly charged and BANK2 is almost dead, both
banks will only get what charge they need on the BOTH setting?



It'll work great. If the alternator is directly connected to the Bank 2
batteries, either at the battery or the post, moving the switch won't blow
anything as the alternator is always hooked to a battery. The batteries
will charge themselves. The little recharge on the starting battery won't
even start until the parallel connected house battery load allows the
alternator voltage to rise up above the starting battery's current
voltage....It'll be fine.

Don't forget to switch from the BOTH position as soon as you shut down the
engine, though....

On 20 Mar 2006 09:30:02 -0600, Dave wrote:

Is your suggestion the I
start the engine on the starting battery, run it a bit, shut it down, switch
to both batteries and the complete the charging?

That's how I do it.

Or you can use a combiner between the starting battery and the house
batt. That makes everything automatic.

On 20 Mar 2006 21:23:05 -0600, Dave wrote:

Hmm. I'm figuring that if I've got a marginal situation, I'd rather not use
the starting battery's juice to charge the house battery before I use it to
start the engine.

I agree. Start the engine first and get it warmed up for a few
minutes. Better safe than sorry if you really need to get started.

"Larry" wrote

I think a lot of these tales about blown alternators, parallel
batteries,
etc., goes way back into the generator days with the vibrating
mechanical
voltage regulators.....

That jogs my memory about the catboat stories of a few days ago. I
opened up the dead regulator that boiled the batteries nearly dry and
the inside looked like nothing more than a doorbell or some kind of
complex relay.

Of course, this was back when I was pondering such problems as created
when the removal of the 32 KB computer from the upper deck of a 210
foot research ship had such an effect on it's weight and stability
that it got very light, corky, and uncomfortable. I had to figure out
how many tons of weight to add back to make it comfortable again.

Interesting how memories link together. Another thing I remember
about that catboat [This section automatically deleted by the Family
Values Protection Email Scanning Program of the Homeland Security
Master Surveillance Computer.]

--

Roger Long

"Roger Long" wrote in newsmRTf.5154$Mj.3933
@twister.nyroc.rr.com:

That jogs my memory about the catboat stories of a few days ago. I
opened up the dead regulator that boiled the batteries nearly dry and
the inside looked like nothing more than a doorbell or some kind of
complex relay.



You're fairly close. It's a buzzer. The coil goes across the battery
terminals and has higher resistance, a calibrated resistance. As the
voltage rises, at some point, the magnetic field the fine wire creates,
which is proportional to the voltage of the battery, overcomes the spring
loading of the armature and pulls the contact, which provides field
current through a limiting resistor (that ceramic thingy on the back),
open. Of course, as soon as the voltage relay opens, battery voltage
drops until the coil can't overpower the armature spring, so the relay
closes again and field current resumes.

This happens fairly rapidly, especially when the battery has finally
charged. The pulsating DC, of variable speed and pulse width determined
by how long the battery voltage supports pulling in the armature, gets
smoothed out by the field coil's inductance into an average DC current
which, of course, sets the alternator (or generator of old) output.

There's still one in my 1973 Mercedes 220 Diesel, mounted to the right
fender inside the engine compartment. Works great. The last big diesel
starting battery lasted 6 years......er, ah, without 3-stage charging,
too!...(c;

The other relay turns on the field current when you turn on the engine
switch. Some have 3 relays. The third relay switches field resistors
(there's 2 on the back of those) to give us two charge rates depending on
how dead the battery is. This third relay pulls in at some level as
battery voltage rises and adds another resistor in series to drop the
field current to a lower level when the battery is nearer charged so we
don't heat up the battery near full charge. It drops out and simply
shorts the extra resistor at low battery voltage to charge it hard when
the battery is dead....or when there's a big load like the 120 amps my
solid state kilowatt HF linear amp draws for the big ham radio station in
the trunk....(c;

Larry wrote:
krj wrote in news:tEXTf.2065$lM3.1135
@bignews3.bellsouth.net:


Three relays. Isn't that three stage charging?




Not hardly. See any tubes glowing in its computer?...(c;



Speaking about 'tube collections'...........
http://www.herald.ns.ca/Search/491270.html

" wrote in
oups.com:

affect the alternators electrronics if you turn the engine
on without disconnecting the charger?

No. Won't matter at all...