Amps, etc.
 

"Richard Casady" wrote in message
. ..
On Wed, 25 Jul 2007 08:37:20 -0500, "KLC Lewis"
wrote:


Pete, do you propose using a hydrometer everytime you want to know your
state of charge? This could be a couple of times each day, or more.

It is, or used to be, the practice on submarines. Not much extra work
when you are checking/adding water. The original smart charger was a
sub sailor with thermometer, hydrometer, and voltmeter. Who knows what

those guys are doing now.

Casady

That raises another question: Just how often are you supposed to check the
water? Once a day? I've been doing it about once a month.

Amps, etc.
 

Amps, etc.
 

Amps, etc.
 

I'm going to try to answer a bunch of questions in the same post, so
am threading it to be under my original post which spawned the Amps
discussion. Due to the multiple responses, this is pretty long
(surprise! Mine are *never* long :{)) )

From: Lew Hodgett


Skip Gundlach wrote:

We don't yet know. We're going to do an energy audit, prolly tomorrow,
to see just exactly how much each item uses.

Add battery capacity, any way you can, it solves a lot of problems
including poor alternator performance.

Lew

We've already got massive batteries. The issue is properly keeping
them charged. At 750 nominal (less aging) AH, we can go for a long
time with no charge input. But if we don't put in the charge,
eventually the biggest battery bank will be flat, even if nothing is
drawn from it, out of normal charge dissapation (flooded = ?%/
month)...

From: Bob


On Jul 23, 8:45 pm, Lew Hodgett wrote:
Skip Gundlach wrote:

We don't yet know. We're gong to do an energy audit, prolly tomorrow,
to see just exactly how much each item uses.

Add battery capacity, any way you can, it solves a lot of problems
including poor alternator performance.

Lew

There is another path............. reduce load = smaller house bank,
smaller battery charger, smaller alt, less engine running, quiter,
cooler, also less things to fix!

Bigger aint always better. My 400 Ah house bank is huge...............
for me :)

We will be carefully monitoring our use once we get our audit
finished. We *believe* (time will tell) that we'll have ample
charging available for the uses we need to put our load to.

From: Bob


On Jul 23, 8:00 pm, Skip Gundlach wrote:
On Jul 23, 12:59 pm, Bob wrote:

Hi Skip:

Do you have a way to determin a battery's level of charge?

Battery Monitor?
Hydrometer?

Bob

Actually, all of the above:

We have a TriMetric 2020 monitor, by Bogart Engineering, which
provides a
lot of information. Volts, amps in or out, state of charge in
percentage
terms are all front-and-center. Menus allow time from equalization,
AH
left, current state of AH up or down in numerical terms, time from and
what
is low and high (two separate measures), and so on.

Our controller for the KISS wind generator (in addition to the on/off
control of the generator itself) is a Xantrex 40A unit. When it's
piping
outside, we can get close to 30A before the internal controls shut
down, but
it doesn't start producing meaningful amps until ~15knots (designed
for the
Caribbean market). It's whisper quiet in our setup; YMMV dependent on
how
well you balance the blades. At full charge, that controller diverts
to a
heat strip setup, required because our water heater wouldn't accept
the dual
voltage unit where we used to send overcharging before we replaced the
water
heater. We have not yet installed (because we can't find where we
stored
them) an incandescent monitor lamp so that if that's happening we can
hurry
and turn on charging loads for AC devices, taking advantage of the
overstock
of amps.

Our controller for the 370W of high-voltage Solar is a Blue Sky 6024H
MPPT,
which provides as much as 30% more than the rated values of our
panels. At
9AM in Charleston, we typically show 12-15A, and at best, sometimes as
much
as 25A in mid-day. That controller just turns off the load (open-
circuits
the panels, I think is what's happening) when they're full. It also
has an
equalizer button, but with 750AH, it's unlikely we'll ever see enough
amperage to actually accomplish that, even connected to shore power.

We also have a battery conditioner attached - it uses the battery's
own
power to pulse, helping prevent/minimize sulphation. The very long-
cycle
charge regime of the solar and wind has meant that we very rarely see
less
than "full" on the monitor. Making sure we see above 13V nearly all
the
time we're not running huge loads is the bigger deal...

Our new shoreside battery charger is a Xantrex TrueCharge40A unit. We
have
4 L16H in series/parallel 12V, plus the windlass and starter
batteries
separated on an isolator. The shore charger, plus whatever solar and
wind
input has occurred since the TC40 installation has brought us back to
full,
with SGs previously in the 1.250 range to over 1.265 in all cells and
no
large variance (65, 65, 70, 75, 75, 75, 85, 80, 90, 80, 75, 75 in the
12
cells) either from cell to cell or in individual batteries.

We have no remaining halogen bulbs (haven't taken out the foredeck
light;
might be one in there) due to their current draw. All on board
lighting is
either fluorescent or LED, outside is either LED or the afore-debated
incandescent running/steaming lights left so because of "all the
current
available during engine operation" - which I may have to re-
evaluate...

From: Lew Hodgett


Bob wrote:


There is another path............. reduce load = smaller house bank,
smaller battery charger, smaller alt, less engine running, quiter,
cooler, also less things to fix!

Bigger aint always better. My 400 Ah house bank is huge...............
for me :)

As long as you remember that you must replace 125AH for every 100AH
consumed and the max sustained recharge rate is 15% of the battery
bank AH capacity.

Being realistic, over time, electrical consumption will increase, not
decrease.

These days, minimalists are few and far between.

Heh. Guilty as charged (pardon the expression). But, we believed
that we provided for that in our initial design. It proved that we
were dependent on a charging source (the prior 70A NewMar beast) which
wasn't happening. We'd not have behaved as we did onshore, at the
hook. That we discovered our alternator simultaneous problem, we feel,
now that it's corrected (more below), that the shore and engine
charging parts are up to snuff.

From:

Skip,

I strongly suggest that you get a digital voltmeter with at least one
decimil place readout and wire it into your system. Use a selector
switch so that you can read the voltage of any battery bank. It is
priceless for monitoring what is going on with the electrons.

The one I have is a LED readout so it is easy to see at night.

You can use it to check everything - charging? It will climb up to
about 14.4 volts and then drop off to about 13.6, or if you are using
a manual charger you can monitor voltages and switch the charger at
the appropriate time. How much power are your nav lights using just
switch them on and check the voltage. Ho! Ho! Turned the lights on and
the voltage driopped 0.1 volts at 12.7 volts. A little math and you
know how much power yout lights draw.

We have such a meter, but have not wired it in. It's part of a
multimeter that I use all the time. It's what I used to determine
that the alternator shop had mis-ended (male instead of female) the
tach lead on the new 94A unit.

OTOH, we have a pretty good one in the TriMetric, also digital, with
10ths in both amps and volts. We keep an eagle eye on it...

When we put in the new alternator, we (with a full battery bank) shut
off the shore charger, turned on the inverter, and loaded up
absolutely everything we could on the boat. Inverter with all the
electrical stuff we could find (two computers, all the charging
equipment for handhelds, three fans, etc.). Every single instrument
and light, in and out. All the pumps rated for continuous duty, with
salt and fresh water taps left open. All the AC and DC fans, engine
room and otherwise. The one single remaining incandescent wall
fixture. The fuel polisher and reefer, etc.

We managed to create just under 50A of load. Short of transmitting on
the SSB/Ham (we did it in standby, for only 2A), that's the worst it
can possibly get with no outside input. Of course, letting it go like
that, for an extended period of time, even with the capacity of our
bank, would be very hard on the battery were there no input.

So, after letting it consume about 15AH (per the TriMetric), we
cranked up the alternator. WhoooEEEE!

The meter went from -48 to +40, and slowly started to come down. The
battery voltage, which, by now, had been down to about 12.1 due to all
the drop, steadily climbed. It quite quickly reached well over 13,
and kept climbing.

Of course, that's also way more drop than we'd likely get before we
did something about the load, but it was very reassuring to see that
not only could we sustain that load at about 1500RPM, but put as much
back in as our shore power charger would in a no-load situation.

So, once we'd proven the point, we shut down most of the loads other
than the computers which were both on (connected to shorepower
otherwise), and saw the voltage immediately charge rate climb, level
off, and then start to taper. We got to 14.4 and things started to
calm down.

Having proven *that* point, we shut it down to keep the temps in the
boat somewhat reasonable, and reconnected the shore power. The
batteries were recovered (14.4, then equalibrium at 13.3, with the
shore power cycling occasionally, and the solar cycling in and out as
well, providing ~10A at that time of day, when it wasn't full.

Significantly, the radar didn't drop out when we started the engine,
whereas it always had before. Seatrialing the instruments is next,
but I'm convinced that our problems will either be entirely, or
mostly, resolved with the proper application of power. As it is, my
freezer is well under spec, running so fast that the evaporator
briefly acts as a cold plate, resulting in an under-temp spec (it
comes up relatively quickly to the set temp), where we've been
struggling to keep it under freezing, let alone the 4 or 5 it is now
(set point 8, 2* hysteresis).

From: Pete C


On Jul 24, 5:46 am, Bob wrote:
On Jul 23, 8:00 pm, Skip Gundlach wrote:

On Jul 23, 12:59 pm, Bob wrote:

Hi Skip:

Do you have a way to determin a battery's level of charge?

Battery Monitor?
Hydrometer?

Bob

Somehow I think Skip would prefer to spend time writing lengthy
cruising blogs, than learning about S.G. levels... =)

Hm. How many times do I have to sample to earn my merit badge? In 5
days I've been in Charleston, I've done it 3 times.

:{))

From: RW Salnick


Jeff brought forth on stone tablets:
BTW, I agree about the DVM, its essential on any boat that has more than
a minimal electrical system. Better yet is an Amp-hour meter, certainly
pricey but worth every penny if you have larger loads, such as a fridge,
and tend to live off-grid.

I second the comment that you need a way to monitor amp-hours in and out
of your batteries - it is the only real "fuel gauge" for batteries that
there is. And it is essential if you are not living plugged into shore
power. We have a Link 2000 and I absolutely love it.

I *think* I have such in the TriMetric...

That ought to hold us for a while. I'd bother the librarian but Lydia
would complain - and, besides, I'd rather write :{))

Well, no. I'm changing my tag line on the skype and googlechats to
"I'm in the engine room, but try anyway - I may hear it" - it used to
be that I was in the bilge.

Hands, please, for those who have spent more than 100 hours in their
engine rooms in the last month - I have - in addition to doing the
research and running around to fix those things which have cropped up
(Roger, I know you qualified last year)...

PS to Geoff - has the above eased your concerns about our
instruments? It's why we're still here...

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.google.com/group/flyingpiglog and/or
http://groups.yahoo.com/group/TheFlyingPigLog

"Twenty years from now you will be more disappointed by the things
you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails.
Explore.
Dream. Discover." - Mark Twain

Amps, etc.
 

Skip Gundlach wrote:


We've already got massive batteries. The issue is properly keeping
them charged. At 750 nominal (less aging) AH, we can go for a long
time with no charge input.

A 750AH bank will require an alternator that can put out about
110A-115A at engine idle to properly recharge them.

This will require a dual belt drive such as is required to drive a
Leece-Neville machine.

If you don't need a dual belt drive with your present alternator, you
have the wrong alternator.

If you discharge this bank by 40%, you have consumed 300AH which must
be replaced with 1.25*300 = 375 AH.

To replace 375 AH you will require 375/115 = 3.3 hours of engine time.

It ain't rocket science.

Nobody said wet cell batteries were efficient, but they are mobile.

Yes I must confess.

In my misspent youth, worked on the engineering team that designed the
great-great-great-great-grandfather of the L/N 4800.

Lew

Amps, etc.
 

On Jul 25, 10:39 pm, Lew Hodgett wrote:
Skip Gundlach wrote:

We've already got massive batteries. The issue is properly keeping
them charged. At 750 nominal (less aging) AH, we can go for a long
time with no charge input.

A 750AH bank will require an alternator that can put out about
110A-115A at engine idle to properly recharge them.

This will require a dual belt drive such as is required to drive a
Leece-Neville machine.

If you don't need a dual belt drive with your present alternator, you
have the wrong alternator.

If you discharge this bank by 40%, you have consumed 300AH which must
be replaced with 1.25*300 = 375 AH.

To replace 375 AH you will require 375/115 = 3.3 hours of engine time.

It ain't rocket science.

Nobody said wet cell batteries were efficient, but they are mobile.

Yes I must confess.

In my misspent youth, worked on the engineering team that designed the
great-great-great-great-grandfather of the L/N 4800.

Lew

Hi, Lew, and thanks for the expansion.

We have as a target of never letting our batteries get below 75% - and
only rarely below 90%. Recent excitement aside, we've succeeded in
that. Our original tests of relying solely on solar and wind (last
year, on the hard), for 6 months, went very well. Of course, we
didn't have the same wind as normally seen in the water, and also
didn't run instruments, offsetting that.

Our solar and wind were calculated to provide somewhere between 150
low and 300 high AH/Day on average. Continuously cloudy (well,
raining - it was completely overcast here at 5 and we were still
getting 12A from the solar), windless days will throw that off, of
course. However, we watch that meter like a hawk, and having had a
bit of training about the interface of volts and amps as to what's
happening in there, believe we'll be better managers than before.

If we were dependent on our engine alternator entirely for recharging,
we'd prolly do something different. However, as backup, but aboard
for our use of power tools in strange countries, as well as our hookah
rig, we have a 2000w Honda much bruited about here on other
occasions. Were it necessary while on the hook, likely we'd start
that before the diesel, solely for charging.

However, of course, having just slain the dragon of no effective
alternator power (and shore charging, too, but we expect that to be so
infrequent as to be unworthy of mention other than as powered by a
Honda if needed), we have no track record to fall back on. Stay tuned
as we live on the hook and under way in the next few weeks...


L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.google.com/group/flyingpiglog and/or
http://groups.yahoo.com/group/TheFlyingPigLog

"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in its
hands. You seek problems because you need their gifts."
(Richard Bach, in The Reluctant Messiah)

Amps, etc.
 

Skip Gundlach wrote in
oups.com:

The meter went from -48 to +40, and slowly started to come down. The
battery voltage, which, by now, had been down to about 12.1 due to all
the drop, steadily climbed. It quite quickly reached well over 13,
and kept climbing.



POWER is our FRIEND!



Larry
--
Transportation and Support
S/V "Flying Pig"
Ask Skip how a Mercedes runs on old frying oil...(c;

Amps, etc.
 

Lew Hodgett wrote in news:1QTpi.12042$zA4.313
@newsread3.news.pas.earthlink.net:

To replace 375 AH you will require 375/115 = 3.3 hours of engine time.



A pipe dream of battery chemistry. 375AH requires 5 hours (from 50%
discharge, not zero) at 38A, not 115. Batteries charge at 10% of AH
rating, not 30, if you want to convert the electrolyte, giving it time
for circulation.

The two batteries will recharge from 50% very nicely at moderate
temperature at 75A for 5 hours on the new 90A alternator. NO battery
will charge at 115A for very long before the interplate electrolyte has
been converted faster than it can be replaced by convection in the
electrolyte. This is why you see the current drop in the first
place....NOT because it has become charged. After the initial current
blast has reconverted lead sulphate into acid, that acid must move out of
the way to be replaced by more lead sulphate ions convecting in from
below by the heat of charging. There's quite a circulation. Charging
too fast, say at 115A trying to force it fast, only results in the
conversion of H2O into hydrogen gas and lead oxide, that violent gas
bubbling it's doing at high charger currents, once the initial lead
sulphate to sulfuric acid conversion has wained on the initial blast.

I suppose we could build a magnetic drive circulator pump into the bottom
of the cells under the plates and you could charge the hell out of it,
then....

Larry
--
Charging takes time.....the more time, the better.

Amps, etc.
 

Larry wrote in
:

Lew Hodgett wrote in
news:1QTpi.12042$zA4.313 @newsread3.news.pas.earthlink.net:

To replace 375 AH you will require 375/115 = 3.3 hours of engine
time.



A pipe dream of battery chemistry. 375AH requires 5 hours (from 50%
discharge, not zero) at 38A, not 115. Batteries charge at 10% of AH
rating, not 30, if you want to convert the electrolyte, giving it time
for circulation.

The two batteries will recharge from 50% very nicely at moderate
temperature at 75A for 5 hours on the new 90A alternator. NO battery
will charge at 115A for very long before the interplate electrolyte
has been converted faster than it can be replaced by convection in the
electrolyte. This is why you see the current drop in the first
place....NOT because it has become charged. After the initial current
blast has reconverted lead sulphate into acid, that acid must move out
of the way to be replaced by more lead sulphate ions convecting in
from below by the heat of charging. There's quite a circulation.
Charging too fast, say at 115A trying to force it fast, only results
in the conversion of H2O into hydrogen gas and lead oxide, that
violent gas bubbling it's doing at high charger currents, once the
initial lead sulphate to sulfuric acid conversion has wained on the
initial blast.

I suppose we could build a magnetic drive circulator pump into the
bottom of the cells under the plates and you could charge the hell out
of it, then....

Larry

Lew, try a little experiment to showcase my assertion:

Charge like hell until the voltage rises up and shut her down with NO
LOAD on the batteries. Wait 30 minutes. Charged batteries will still be
charged and immediately draw little current at float voltage.

Crank the alternator-from-hell back up and watch the current....It'll go
back to hard charging at lower-than-float voltage because the convection
in the electrolyte has replaced the supercharged electrolyte with
uncharged electrolyte to continue the replating process. The current
will drop and voltage will repeat its rise charging this hard as
electrolyte, once again, becomes saturated before convection takes place.

You can repeat the phenomenon over and over with no load on the battery
between charges.

Once the cells are TRULY charged, there will be a small current when
charging starts, but the voltage will already be high putting charging in
float mode almost immediately.

Larry
--
SLOWLY.....we recharge SLOWLY.....

Amps, etc.
 

Larry wrote:


A pipe dream of battery chemistry. 375AH requires 5 hours (from 50%
discharge, not zero) at 38A, not 115. Batteries charge at 10% of AH
rating, not 30, if you want to convert the electrolyte, giving it time
for circulation.

Spoken with the vision of a person with his head squarely placed where
the moon doesn't shine.

Plonk

Lew