This is all really good information, and I wished that I had read and digested
it a year or so ago. Those are exactly the voltages I am seeing on mine now,
and I'm glad to know that is just what it is supposed to do. I mentioned
something earlier this summer about burning a couple of alternator belts up.
Well, I have 125 amp Balmer alternator, and the Balmar smart regulator. And I
think I had it set to 95% charge, which was as I recall recommended on their
chart. But, for some reason that sucker was charging its little heart out, and
burning belts up like crazy. I think something was wrong with my heart
interface because I later discovered the inverter was stuck on. That was
another problem. Later, I reset the heart back to factory defaults, and it
started working perfectly again. This time, I never made any adjustments to it
or set the battery amp hours or anything. It's working perfectly, so I'm
letting sleeping dogs lie. However, the ballmart rep recommended cutting it
down to 65% charge on the smart regulator, and I haven't felt any need to
change that since them. Although, I did get the alternator temperature
regulator, tied into the smart regulator. Once you go through one of these
things in strange ports, you never want experience them again.
Regards,
Bill ColemanC&C 39
-------- Original message --------
From: Josh Muckley via CnC-List <cnc-list@cnc-list.com>
Date: 10/16/17 21:32 (GMT-05:00)
To: C&C List <cnc-list@cnc-list.com>
Cc: Josh Muckley <muckl...@gmail.com>
Subject: Re: Stus-List New Engine, now what size alternator
Joe, the damage I was considering would be caused by exceeding the charge rate
for the bank size. The conventional wisdom is that typical lead acid batteries
should not be charged at a rate greater than 25% of their capacity. A 100 AHr
battery would be limited to 25 amps. Isn't it possible to exceed the charge
rate with a good regulator? Particularly applicable when the battery is more
deeply discharged.
All of the 3 and 4 stage regulators I've ever seen will ramp up to max amps
and hold there until ~14.6 volts is reached (80% full - end of bulk charge) at
which time the voltage will be held constant at ~14.6v as the amps are reduced.
Once the amps lower to ~2amps the regulator shifts to float mode and lowers
the voltage to ~13.3v and holds it indefinitely.
As an example lets say that you are using a 100 amp alternator and regulator to
charge a 100AHr battery bank that has been discharged to 50% capacity. Isn't
it likely that the charge current will ramp to 100 amps? Or at least greater
than 25 amps? What other regulator function would prevent this from happening?
I suppose battery temperature could input to the alternator so as to reduce
charge current. Though, I'm not sure that battery temperature responds quickly
enough to prevent early over current damage, only overcurrent damage as a
result of longer term charging current which has been applied long enough to
raise temperature to the threshold.
Josh
On Oct 16, 2017 3:01 PM, "Della Barba, Joe via CnC-List"
<cnc-list@cnc-list.com> wrote:
Wrecking batteries with a big alternator is why you need a good regulator. If
you are counting on the alternator itself to just be unable to do any damage
because
it can’t, you are taking a big risk or and have a very suboptimal charging
setup.
For an extreme example, given a decent regulator, a 1000 amp alternator should
do no harm and you can very much destroy batteries with a 35 amp alternator.
I once worked on a boat whose genset had a 35 amp alternator set to 16 volts.
The owner was buying several batteries a year and didn’t know why.
Joe
Coquina
From: CnC-List [mailto:cnc-list-boun...@cnc-list.com]
On Behalf Of Josh Muckley via CnC-List
Sent: Monday, October 16, 2017 2:50 PM
To: C&C List <cnc-list@cnc-list.com>
Cc: Josh Muckley <muckl...@gmail.com>
Subject: Re: Stus-List New Engine, now what size alternator
Not only will they not absorb the charge quickly enough, exceeding the charge
rate will boil the batteries more than staying within the charging guidelines.
An alternator that is too big for the bank will seriously risk damaging the
batteries.
Larger alternators under full load will also strain the v-belt. Additional
tention will need to be applied to prevent the belt from slipping. The
additional tension puts additional side loads on the crankshaft end bearing.
Lets also remember that full output is only achieved under full RPM. Many
people enjoy the idea of idling along or running the engine for a few hours in
neutral. Not only does this not achieve the full rated output of the
alternator but
it can also coke up the exhaust elbow and glaze the cylinders. Diesel engines
should be run at 80% as often as possible and for as long as possible.
Josh
On Oct 16, 2017 2:19 PM, "Joel Aronson via CnC-List" <cnc-list@cnc-list.com>
wrote:
With a small battery bank you will not benefit from the larger alternator. The
batteries can't absorb a charge that quickly.
Joel
Virus-free.
www.avg.com
On Mon, Oct 16, 2017 at 1:25 PM, David via CnC-List <cnc-list@cnc-list.com>
wrote:
Let me expound a bit on alternators and engine size. When replaced my dumb
alternator with a Balmar set-up (alternator, smart Charger, digital Duo etc )
on my 33 hp diesel Balmar recommended
no more than the 80 amp because of the loss of HP which I could ill afford.
If you have HP to spare...go for it. If not reconsider.
1981 40-2
David F. Risch
(401) 419-4650 (cell)
From: CnC-List <cnc-list-boun...@cnc-list.com>
on behalf of Josh Muckley via CnC-List <cnc-list@cnc-list.com>
Sent: Monday, October 16, 2017 12:47 PM
To: cnc-list@cnc-list.com
Cc: Josh Muckley
Subject: Re: Stus-List New Engine, now what size alternator
Paul, Thanks for these more accurate "ratings". It definitely helps to give an
answer to the question of "what does good look like?" I have never saught out
actual ratings for
refrigerator loads and I've never gotten a AHr meter installed - besides the
plethora of variables which make single point AHr usage almost impossible to
determine. It seemed like nobody else had provided a frame of reference
besides examples of their own
setup and I was kinda trying to describe a worst case numbers scenario to
provide an upper boundary to the project. Your numbers bring further clarity
by providing a lower boundary.
You and other listers are absolutely correct that adding insulation is the best
way to reduce refrigerator AHr load.
Thanks,
Josh Muckley
S/V Sea Hawk
1989 C&C 37+
Solomons, MD
On Mon, Oct 16, 2017, 9:20 AM Dreuge via CnC-List <cnc-list@cnc-list.com> wrote:
If you have a refrigeration load of 120AH/day, don’t waist money on increasing
battery and charging capacity.
Spend a little cash on better insulation or rebuild your box with more and
better insulation. It is not unreasonable to shoot for a refrigeration load
under 30AH/day. Just
have a look at Wally’s Stella Blue page titled “Marine refrigeration and
freezer on 22AH/day”(I recall he has a Frigoboat unit with keel cooler).
Technautics claim that their CoolBlue system consumes “24AH/Day for a 7 cubic
foot fridge/freezer with R-30”
and “operates at ambient temperatures up to 120F without a loss in system
efficiency.” Even the Isotherm claims their ASU SP3751 can achieve loads
under 20AH/day. Now making ice or cooling down warm beer on a really hot day
will likely have higher load
demands, but the message is still the same. Insulation is cheaper than
batteries and lasts a lot longer too.
-
Paul E.
1981 C&C 38 Landfall
S/V Johanna Rose
Fort Walton Beach, FL
http://svjohannarose.blogspot.com/
On Oct 14, 2017, at 2:02 PM,
cnc-list-requ...@cnc-list.com wrote:
Lets consider some hypothetical numbers based on the rep's info. If a 100w
panel were %100 effective and operated for 8 hours, you would get 800w-hrs
of power per day. 800w divided by 12v = 67amp-hrs. 67 divided by 24hrs =
2.8amps current draw on average.
That kinda gives you a ball park for what type of loads you'll be facing.
Round up to 5amps/hr if you like for margin. 5 *24=120AHr per day.
_______________________________________________
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_______________________________________________
The bills have started coming in for the year 2018 and have gone up again.
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All contributions are greatly appreciated!
_______________________________________________
The bills have started coming in for the year 2018 and have gone up again.
October will be our fund raising month. Please consider sending a small
contribution to help keep this list running. Use PayPal to send contribution
-- https://www.paypal.me/stumurray
All contributions are greatly appreciated!
_______________________________________________
The bills have started coming in for the year 2018 and have gone up again.
October will be our fund raising month. Please consider sending a small
contribution to help keep this list running. Use PayPal to send contribution
-- https://www.paypal.me/stumurray
All contributions are greatly appreciated!
