I found this information in a e-book called "Batteries in a Portable
World" by Buchmann. In our ongoing watered golf cart vs. expensive
maintenance-free gauze battery discussion, there are some very revealing
facts the author points out that I'm sure the battery sales people
wouldn't want you to look at too closely...

Sorry for the wordwrapping nonsense I can't seem to stop....

It says:

"The Lead Acid Battery
Invented by the French physician Gaston Planté in 1859, lead acid was the
first rechargeable battery for commercial use. Today, the flooded lead
acid
battery is used in automobiles, forklifts and large uninterruptible power
supply (UPS) systems.
During the mid 1970s, researchers developed a maintenance-free lead acid
battery, which could operate in any position. The liquid electrolyte was
transformed into moistened separators and the enclosure was sealed.
Safety
valves were added to allow venting of gas during charge and discharge.
Driven by diverse applications, two
designations of batteries emerged.
They are the sealed lead acid (SLA),
also known under the brand name of
Gelcell, and the valve regulated lead
acid (VRLA). Technically, both
batteries are the same. No scientific
definition exists as to when an SLA
becomes a VRLA. (Engineers may
argue that the word ‘sealed lead acid’ is a misnomer because no lead acid
battery can be totally sealed. In essence, all are valve regulated.)
The SLA has a typical capacity range of 0.2Ah to 30Ah and powers portable
and wheeled applications. Typical uses are personal UPS units for PC
backup,
small emergency lighting units, ventilators for health care patients and
wheelchairs. Because of low cost, dependable service and minimal
maintenance requirements, the SLA battery is the preferred choice for
biomedical and health care instruments in hospitals and retirement homes.
The VRLA battery is generally used for stationary applications. Their
capacities range from 30Ah to several thousand Ah and are found in larger
UPS systems for power backup. Typical uses are mobile phone repeaters,
cable distribution centers, Internet hubs and utilities, as well as power
backup
for banks, hospitals, airports and military installations.
Unlike the flooded lead acid battery, both the SLA and VRLA are designed
with a low over-voltage potential to prohibit the battery from reaching
its
gas-generating potential during charge. Excess charging would cause
gassing
and water depletion. Consequently, the SLA and VRLA can never be charged
to their full potential.
Among modern rechargeable batteries, the lead acid battery family has the
lowest energy density. For the purpose of analysis, we use the term
‘sealed
lead acid’ to describe the lead acid batteries for portable use and
‘valve
regulated lead acid’ for stationary applications. Because of our focus on
portable batteries, we focus mainly on the SLA.
The SLA is not subject to memory.
Leaving the battery on float charge for a
prolonged time does not cause damage.
The battery’s charge retention is best
among rechargeable batteries. Whereas the
NiCd self-discharges approximately
40 percent of its stored energy in three
months, the SLA self-discharges the same
amount in one year. The SLA is relatively inexpensive to purchase but the
operational costs can be more expensive than the NiCd if full cycles are
required on a repetitive basis.
The SLA does not lend itself to fast charging — typical charge times are
8 to 16 hours. The SLA must always be stored in a charged state. Leaving
the
battery in a discharged condition causes sulfation, a condition that
makes the
battery difficult, if not impossible, to recharge.
Unlike the NiCd, the SLA does not like deep cycling. A full discharge
causes
extra strain and each discharge/charge cycle robs the battery of a small
amount of capacity. This loss is very small while the battery is in good
operating condition, but becomes more acute once the performance drops
below 80 percent of its nominal capacity. This wear-down characteristic
also
applies to other battery chemistries in varying degrees. To prevent the
battery
from being stressed through repetitive deep discharge, a larger SLA
battery is
recommended.
Depending on the depth of discharge and operating temperature, the SLA
provides 200 to 300 discharge/charge cycles. The primary reason for its
relatively short cycle life is grid corrosion of the positive electrode,
depletion
of the active material and expansion of the positive plates. These
changes are
most prevalent at higher operating temperatures. Applying
charge/discharge
cycles does not prevent or reverse the trend.
There are some methods that improve the performance and prolong the life
of
the SLA. The optimum operating temperature for a VRLA battery is 25°C
(77°F). As a rule of thumb, every 8°C (15°F) rise in temperature will cut
the
battery life in half. VRLA that would last for 10 years at 25°C would
only be
good for 5 years if operated at 33°C (95°F). The same battery would
endure a
little more than one year at a temperature of 42°C (107°F).
The SLA has a relatively low energy density compared with other
rechargeable batteries, making it unsuitable for handheld devices that
demand
compact size. In addition, performance at low temperatures is greatly
reduced.
The SLA is rated at a 5-hour discharge or 0.2C. Some batteries are even
rated
at a slow 20 hour discharge. Longer discharge times produce higher
capacity
readings. The SLA performs well on high pulse currents. During these
pulses,
discharge rates well in excess of 1C can be drawn.
In terms of disposal, the SLA is less harmful than the NiCd battery but
the
high lead content makes the SLA environmentally unfriendly. Ninety
percent
of lead acid-based batteries are being recycled."

Most interesting....
No wonder they last longer up north where it's colder than here in the
tropics....contrary to the idea of pulling them out of the boat and
putting them in a warm place all winter... Looks like they're better off
in the boat under the snow!

Larry,

How would you count a charge / discharge cycle according to this article?
When I use my two paralleled AGM's to start my little 15 hp diesel, is that
a cycle? I don't see how it could be since I sail nearly every day during
the summer and my batteries ought to be nearly dead now. If the battery is
good for 200 cycles and my draw down is only 10% (In reality, it's probably
less than that since my engine lights of almost as quickly as a good car
engine) can I expect to get closer to 2000 charging cycles?

I feel even better about leaving my batteries in the boat now. Thanks for
the article.

--
Roger Long

Roger Long wrote:
Larry,

How would you count a charge / discharge cycle according to this
article? When I use my two paralleled AGM's to start my little 15 hp
diesel, is that a cycle? I don't see how it could be since I sail
nearly every day during the summer and my batteries ought to be nearly
dead now. If the battery is good for 200 cycles and my draw down is
only 10% (In reality, it's probably less than that since my engine
lights of almost as quickly as a good car engine) can I expect to get
closer to 2000 charging cycles?

I feel even better about leaving my batteries in the boat now. Thanks
for the article.


Roger, starting a 15 hp diesel probably takes less than 80 amps for 20
seconds. This is less than half an amp-hour, probably less than one
percent of the battery's capacity. Mere noise in charge/discharge cycle
space.

Chuck

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

"Roger Long" wrote in
:

How would you count a charge / discharge cycle according to this
article? When I use my two paralleled AGM's to start my little 15 hp
diesel, is that a cycle? I don't see how it could be since I sail
nearly every day during the summer and my batteries ought to be nearly
dead now. If the battery is good for 200 cycles and my draw down is
only 10% (In reality, it's probably less than that since my engine
lights of almost as quickly as a good car engine) can I expect to get
closer to 2000 charging cycles?



I believe he was referring to drawing down the battery in a deep
discharge cycle, not just a burst of starter current. Hell, we'd have to
put 4 batteries a year in my car if that were so...(c;

A good diesel fires on the 2nd TDC it rolls over. When Dan had the old
Hatteras 56, I told him I'd be afraid to jack over the 8v92TAs by hand as
they would probably start as soon as something moved. Both those engines
you just touched the starter and they popped up running...2-strokes,
gotta love 'em.

I think the 300 real cycles, using the batteries for lights and loads,
then recharging them properly to full charge SLOWLY is quite realistic
for lead acid AGMs or Gelcells. I just spent $70 putting 2 new 12AH AGMs
in my dock scooter. It's like driving a hot rod! Even at full throttle,
the status light stays green as soon as it comes up to speed. The acid
soaked gauze gets used up in about 200 cycles in the scooter....less than
a year the way I use it all summer.

There were very important graphs to study in this report that boaters
need to see, especially about charging....

I found the book for free on his website:
http://www.buchmann.ca/toc.asp

In figure 4-3 on pdf page 61, notice how the 3-stage charging is measured
in HOURS, not running the diesel for 30 minutes like boaters dream of.
Notice how the current drops very rapidly near the start of the charge,
not when the charge is near complete. My assertion of why it's stupid to
put a 140 amp alternator on a little sailboat diesel is obvious.

The accompanying text:
"A multi-stage charger applies constant-current charge, topping charge
and float
charge (see Figure 4-3). During the constant current charge, the battery
charges
to 70 percent in about five hours; the remaining 30 percent is completed
by the
slow topping charge. The topping charge lasts another five hours and is
essential
for the well-being of the battery. This can be compared to a little rest
after a
good meal before resuming work. If the battery is not completely
saturated, the
SLA will eventually lose its ability to accept a full charge and the
performance
of the battery is reduced. The third stage is the float charge, which
compensates
for the self-discharge after the battery has been fully charged."

See the time in HOURS, not MINUTES? He's especially talking about AGM
and Gelcell batteries boaters think are superbatteries because of the
awful prices. So, you're looking at charging them for several hours, not
just when the charging voltage pops up as is so often the case in a boat
trying to get that diesel shut down ASAP...shortening battery life in the
process by first overcharging, then not giving the chemistry TIME to
charge the cells. To quote the text, again:

"The charge algorithm for lead acid batteries differs from nickel-based
chemistry
in that voltage limiting rather than current limiting is used. Charge
time of a
sealed lead acid (SLA) is 12 to 16 hours. With higher charge currents and
multi-stage charge methods, charge time can be reduced to 10 hours or
less.
SLAs cannot be fully charged as quickly as nickel-based systems."

10 HOURS, not 30 minutes. Most sailboat captains would have a heart
attack....(c;

Of course, if you're headed back to the dock to plug in the little 10A
chargers...or a mooring with big solar panels or wind charger...that's
exactly what happens...HOURS.

I still prefer liquid electrolyte to gells and wicks. I can charge them
to a full charge and replace any electrolyte that vents. I can also
adjust their specific gravity to balance the cells over time to maximize
life. "Maintenance Free" just means you can't help them, once they start
down.



Larry
--
Why is it, in any city, all traffic lights act as if they have rotary
timers in them, like they did in 1955, and are all set to create
maximum inconvenience and block traffic movement, entirely?

The battery power required to start the engine raises a question for me. I
have a Universal 18 in my boat. I have not tried to manually crank it by
attaching a handle to the crank shaft, but I have been told that it can be
done by hammering a wrench socket onto the shaft, and cranking it with a
ratchet. It seems like this would be a good way to conserve battery power
if there were a non-destructive way to manually crank the engine. Is there
some sort of racheted, removable socket that would fit on the shaft to
enable a manual crank, sort of like automobile crank handles at the turn of
the century? A little elbow grease might save a tree in the long run.


"Larry" wrote in message
...
"Roger Long" wrote in
:

How would you count a charge / discharge cycle according to this
article? When I use my two paralleled AGM's to start my little 15 hp
diesel, is that a cycle? I don't see how it could be since I sail
nearly every day during the summer and my batteries ought to be nearly
dead now. If the battery is good for 200 cycles and my draw down is
only 10% (In reality, it's probably less than that since my engine
lights of almost as quickly as a good car engine) can I expect to get
closer to 2000 charging cycles?



I believe he was referring to drawing down the battery in a deep
discharge cycle, not just a burst of starter current. Hell, we'd have to
put 4 batteries a year in my car if that were so...(c;

A good diesel fires on the 2nd TDC it rolls over. When Dan had the old
Hatteras 56, I told him I'd be afraid to jack over the 8v92TAs by hand as
they would probably start as soon as something moved. Both those engines
you just touched the starter and they popped up running...2-strokes,
gotta love 'em.

I think the 300 real cycles, using the batteries for lights and loads,
then recharging them properly to full charge SLOWLY is quite realistic
for lead acid AGMs or Gelcells. I just spent $70 putting 2 new 12AH AGMs
in my dock scooter. It's like driving a hot rod! Even at full throttle,
the status light stays green as soon as it comes up to speed. The acid
soaked gauze gets used up in about 200 cycles in the scooter....less than
a year the way I use it all summer.

There were very important graphs to study in this report that boaters
need to see, especially about charging....

I found the book for free on his website:
http://www.buchmann.ca/toc.asp

In figure 4-3 on pdf page 61, notice how the 3-stage charging is measured
in HOURS, not running the diesel for 30 minutes like boaters dream of.
Notice how the current drops very rapidly near the start of the charge,
not when the charge is near complete. My assertion of why it's stupid to
put a 140 amp alternator on a little sailboat diesel is obvious.

The accompanying text:
"A multi-stage charger applies constant-current charge, topping charge
and float
charge (see Figure 4-3). During the constant current charge, the battery
charges
to 70 percent in about five hours; the remaining 30 percent is completed
by the
slow topping charge. The topping charge lasts another five hours and is
essential
for the well-being of the battery. This can be compared to a little rest
after a
good meal before resuming work. If the battery is not completely
saturated, the
SLA will eventually lose its ability to accept a full charge and the
performance
of the battery is reduced. The third stage is the float charge, which
compensates
for the self-discharge after the battery has been fully charged."

See the time in HOURS, not MINUTES? He's especially talking about AGM
and Gelcell batteries boaters think are superbatteries because of the
awful prices. So, you're looking at charging them for several hours, not
just when the charging voltage pops up as is so often the case in a boat
trying to get that diesel shut down ASAP...shortening battery life in the
process by first overcharging, then not giving the chemistry TIME to
charge the cells. To quote the text, again:

"The charge algorithm for lead acid batteries differs from nickel-based
chemistry
in that voltage limiting rather than current limiting is used. Charge
time of a
sealed lead acid (SLA) is 12 to 16 hours. With higher charge currents and
multi-stage charge methods, charge time can be reduced to 10 hours or
less.
SLAs cannot be fully charged as quickly as nickel-based systems."

10 HOURS, not 30 minutes. Most sailboat captains would have a heart
attack....(c;

Of course, if you're headed back to the dock to plug in the little 10A
chargers...or a mooring with big solar panels or wind charger...that's
exactly what happens...HOURS.

I still prefer liquid electrolyte to gells and wicks. I can charge them
to a full charge and replace any electrolyte that vents. I can also
adjust their specific gravity to balance the cells over time to maximize
life. "Maintenance Free" just means you can't help them, once they start
down.



Larry
--
Why is it, in any city, all traffic lights act as if they have rotary
timers in them, like they did in 1955, and are all set to create
maximum inconvenience and block traffic movement, entirely?

Larry wrote:
Snip

In figure 4-3 on pdf page 61, notice how the 3-stage charging is measured
in HOURS, not running the diesel for 30 minutes like boaters dream of.
Notice how the current drops very rapidly near the start of the charge,
not when the charge is near complete. My assertion of why it's stupid to
put a 140 amp alternator on a little sailboat diesel is obvious.

Snip

In fairness, typical automotive chargers are not rated for use with the
aggressive, constant-current charging cycles used in popular marine
"smart chargers". Replacing the stock alternator with a higher-rated
one when switching to a smart charger is not a bad idea, providing
engine, pulleys, and belts are also willing.

I agree that 30 minutes is not going to restore 50% of capacity on 200
Ah deep-cycle lead acid batteries. With a 140 amp alternator, gasses,
venting, etc., permitting, it would take more than an hour. Hard to
generalize, but with an adequate alternator, belt, engine speed and
charger, it is heat and gassing that ultimately limit the rate at which
you can jam amp-hours into a storage battery, and the better smart
chargers monitor terminal temperature and fold back current to try to
keep things intact. Haven't heard many horror stories of smart chargers
destroying batteries.

Remember too, even though you recover most of the lost charge quickly
through constant-current charging, that last 10-15% is what will take
hours to accomplish under typical voltage-limited charging, even with
smart chargers. So the author quoted is perhaps overconcise in his
statements.

Don't sell the smart chargers too short, Larry! ;-)

Chuck

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Very interesting thoughts about batteries, it took me several years of
observations to reach a similar conclusion.

What I miss is more concrete conclusions about who (manufacturers) is doing
what, based on what you say and what I observed. What would be the best
brand under tropical cruising conditions?

Because all of us would not have enough time in our life to experiment all
brands of batteries available on the market place. I would suggest to
express individual experiences.
Would it be a good idea?

based in the Caribbean sea.



"Larry" a écrit dans le message de news:
...
I found this information in a e-book called "Batteries in a Portable
World" by Buchmann. In our ongoing watered golf cart vs. expensive
maintenance-free gauze battery discussion, there are some very revealing
facts the author points out that I'm sure the battery sales people
wouldn't want you to look at too closely...

Sorry for the wordwrapping nonsense I can't seem to stop....

It says:

"The Lead Acid Battery
Invented by the French physician Gaston Planté in 1859, lead acid was the
first rechargeable battery for commercial use. Today, the flooded lead
acid
battery is used in automobiles, forklifts and large uninterruptible power
supply (UPS) systems.
During the mid 1970s, researchers developed a maintenance-free lead acid
battery, which could operate in any position. The liquid electrolyte was
transformed into moistened separators and the enclosure was sealed.
Safety
valves were added to allow venting of gas during charge and discharge.
Driven by diverse applications, two
designations of batteries emerged.
They are the sealed lead acid (SLA),
also known under the brand name of
Gelcell, and the valve regulated lead
acid (VRLA). Technically, both
batteries are the same. No scientific
definition exists as to when an SLA
becomes a VRLA. (Engineers may
argue that the word 'sealed lead acid' is a misnomer because no lead acid
battery can be totally sealed. In essence, all are valve regulated.)
The SLA has a typical capacity range of 0.2Ah to 30Ah and powers portable
and wheeled applications. Typical uses are personal UPS units for PC
backup,
small emergency lighting units, ventilators for health care patients and
wheelchairs. Because of low cost, dependable service and minimal
maintenance requirements, the SLA battery is the preferred choice for
biomedical and health care instruments in hospitals and retirement homes.
The VRLA battery is generally used for stationary applications. Their
capacities range from 30Ah to several thousand Ah and are found in larger
UPS systems for power backup. Typical uses are mobile phone repeaters,
cable distribution centers, Internet hubs and utilities, as well as power
backup
for banks, hospitals, airports and military installations.
Unlike the flooded lead acid battery, both the SLA and VRLA are designed
with a low over-voltage potential to prohibit the battery from reaching
its
gas-generating potential during charge. Excess charging would cause
gassing
and water depletion. Consequently, the SLA and VRLA can never be charged
to their full potential.
Among modern rechargeable batteries, the lead acid battery family has the
lowest energy density. For the purpose of analysis, we use the term
'sealed
lead acid' to describe the lead acid batteries for portable use and
'valve
regulated lead acid' for stationary applications. Because of our focus on
portable batteries, we focus mainly on the SLA.
The SLA is not subject to memory.
Leaving the battery on float charge for a
prolonged time does not cause damage.
The battery's charge retention is best
among rechargeable batteries. Whereas the
NiCd self-discharges approximately
40 percent of its stored energy in three
months, the SLA self-discharges the same
amount in one year. The SLA is relatively inexpensive to purchase but the
operational costs can be more expensive than the NiCd if full cycles are
required on a repetitive basis.
The SLA does not lend itself to fast charging - typical charge times are
8 to 16 hours. The SLA must always be stored in a charged state. Leaving
the
battery in a discharged condition causes sulfation, a condition that
makes the
battery difficult, if not impossible, to recharge.
Unlike the NiCd, the SLA does not like deep cycling. A full discharge
causes
extra strain and each discharge/charge cycle robs the battery of a small
amount of capacity. This loss is very small while the battery is in good
operating condition, but becomes more acute once the performance drops
below 80 percent of its nominal capacity. This wear-down characteristic
also
applies to other battery chemistries in varying degrees. To prevent the
battery
from being stressed through repetitive deep discharge, a larger SLA
battery is
recommended.
Depending on the depth of discharge and operating temperature, the SLA
provides 200 to 300 discharge/charge cycles. The primary reason for its
relatively short cycle life is grid corrosion of the positive electrode,
depletion
of the active material and expansion of the positive plates. These
changes are
most prevalent at higher operating temperatures. Applying
charge/discharge
cycles does not prevent or reverse the trend.
There are some methods that improve the performance and prolong the life
of
the SLA. The optimum operating temperature for a VRLA battery is 25°C
(77°F). As a rule of thumb, every 8°C (15°F) rise in temperature will cut
the
battery life in half. VRLA that would last for 10 years at 25°C would
only be
good for 5 years if operated at 33°C (95°F). The same battery would
endure a
little more than one year at a temperature of 42°C (107°F).
The SLA has a relatively low energy density compared with other
rechargeable batteries, making it unsuitable for handheld devices that
demand
compact size. In addition, performance at low temperatures is greatly
reduced.
The SLA is rated at a 5-hour discharge or 0.2C. Some batteries are even
rated
at a slow 20 hour discharge. Longer discharge times produce higher
capacity
readings. The SLA performs well on high pulse currents. During these
pulses,
discharge rates well in excess of 1C can be drawn.
In terms of disposal, the SLA is less harmful than the NiCd battery but
the
high lead content makes the SLA environmentally unfriendly. Ninety
percent
of lead acid-based batteries are being recycled."

Most interesting....
No wonder they last longer up north where it's colder than here in the
tropics....contrary to the idea of pulling them out of the boat and
putting them in a warm place all winter... Looks like they're better off
in the boat under the snow!

Larry wrote:
In our ongoing watered golf cart vs. expensive maintenance-free gauze
battery discussion, there are some very revealing facts the author points
out that I'm sure the battery sales people wouldn't want you to look at
too closely...
[snip]

Good stuff. My own experience with lead-acid batteries leads me to
believe that no matter how well you take care of them they don't last
more than a 2 or 3 years. For example I had a pair of deep cycle
marine batteries in the truck to run ham radio equipment, I installed
those in about November of 2004. They aren't deeply discharged, and
the truck is driven every day for at least 20 miles and usually much
more than that, rarely is it left a whole day without moving at all
(when left at an airport only). The radio equipment is on all the time
so there is a constant load and it did happen on rare occasions
(airport) that the batteries would get drained completely, but I
consider that typical of what a cruiser does to batteries, sometimes it
just happens. The batteries have been well maintained, I check the
water in them often and replace it as necessary, and the batteries are
sitting on a wooden battery "tray" that I made for them behind the
passenger seat. I wouldn't say they are pampered, but they certainly
are not abused.

Recently these batteries have degraded to the point that they won't run
the radio equipment over an entire night (10 hours let's say) before
they go completely dead. Now of course those "completely dead"
dicharge cycles are rapidly eating the batteries and sucking out what
life they had left in them, because it's a bad thing to completely
discharge lead acid batteries. But they degrade naturally to that
point, that is to say that I didn't suddenly change my habits, they are
being subjected to the same conditions as when they were first
installed in the truck.

This is very similar to experience I have had with lead acid batteries
over my lifetime, but I always thought that they "died" because I
wasn't taken good enough care of them. I'm convinced now, however,
that it really doesn't matter much, that no matter what you do with
deep cycle lead acid batteries they are not going to last more than
about 2 or 3 years, maybe a few years more if you have a really huge
bank that is under a very light load, and maybe a few years more beyond
that if you are using something more substantial than a marine deep
cycle, something made as a UPS backup for example or for unattended
telephone stations. I have started to think that it's best to just
plan on replacing the bank after 3 or 4 years (conservatively) and buy
accordingly. In any mega-store store you can get 100aH 12vdc batteries
for 50$us/each. So for 2000aH at 12vdc that's about 1000$us, amortized
over 3 years let's say, that's about 333$us/year. Compare that with
West Marine AGM 8D batteries in a bank, 180aH per 12vdc battery for
410$us/battery, that comes out by my math to be 2000aH for
4551$us/bank, or about 4 times as expensive as the cheap lead acid
batteries. Are the expensive ones going to last 4 times as long ? Say
that again ... are the expensive AGM marine deep cycle batteries from
West Marine going to last 12 years ? Anyone have experience that says
yes ? They'd have to last that long to give the same cost/benefit.

Do they last that long ? I have my doubts. In fact, I'm starting to
think that the best way to go is to just find a supplier of the
cheapest thick plate lead acid battery you can find and buy your banks
there with the intention of replacing them all after 3 or 4 years.

"roger lothoz" wrote in
:

Because all of us would not have enough time in our life to experiment
all brands of batteries available on the market place. I would suggest
to express individual experiences.
Would it be a good idea?



AS there is really no difference in the CHEMISTRY of the lead-acid battery,
does it really make any difference who makes the same ol' technology we've
always used?

I think not.

Sales hype and outrageous pricing doesn't change chemistry, much....not
that much.

"purple_stars" wrote in
oups.com:

Recently these batteries have degraded to the point that they won't run
the radio equipment over an entire night (10 hours let's say) before
they go completely dead. Now of course those "completely dead"
dicharge cycles are rapidly eating the batteries and sucking out what
life they had left in them, because it's a bad thing to completely
discharge lead acid batteries.

I used to run a rather powerful HF station mobile:
Yaesu FT-900 remote mounted in trunk
Highly modified TenTec Hercules II, 120 amps from golf cart beasts with
650 watts output to a 15' tall, trailer-hitch-mounted, homebrew using
Henry Allen's Texas Bugcatcher's biggest coil and 8-spoke, 36" capacitor
hat. On 20M, my favorite band, the coil was shorted out, completely, and
the whip on top was tuned so only the capacitor hat was used, pulling the
current lobe way up the mast for more H field. Maybe some day I'll put
it back in the car when the sun cooperates better....

I, too, drove the car every day and didn't really tax it much with much
transmitting power, except on long trips with ham friends. The big
batteries got weaker over time and it took me a while to figure out what
was going on.....

Like you, my daily drive was around 25 miles of city driving, which is
part of the problem. I used a continuous duty solenoid to connect the
ham batteries in parallel with the diesel starting battery in the finest
ham radio car (zero electrical noise) ever invented, the 1973 Mercedes
220Diesel with no electronics, at all. I still drive it. I restored it.

The car has a 80A alternator, plenty of juice, and a huge starting
battery for the diesel.

I started tracking the specific gravity and plotting it after a long
overcharge (2 days) from 1.280 sg. Each day, upon arriving home from the
driving, I got out my hydrometer and recorded/plotted the gravity, the
only REAL means of measuring cell condition in lead acid batteries.

The chart started falling from that first day. Well, maybe it'll level
off at some point, as we did start with a really full charge. Nope, it
never did. The 25-45 mile drive each day in stop and go traffic never
produced enough charging TIME to recover the gravity all the way up to
full, or even close. It looked good on the voltmeter, 14.5 volts
charging, until I stopped or keyed the beast around 140A (with the radio)
on packet or rtty. There simply wasn't enough charge TIME to cause the
chemistry to reverse.

I gave up the test around 1.180, defeated.....

The solution was quite simple. Leave a drop cord by the car and mount a
10A automatic shutoff battery charger in the trunk by the
batteries....and simply plug in the car all night. Specific gravity
recovered the first day from the SLOW, SLOW recharging at 3-4A and each
morning the charger would by slowly cycling on with long off periods as
the battery's high gravity voltage held it off very nicely.

I remoted the charger's AC plug to under the trailer hitch to make
connecting it as easy an painless as possible. The batteries went from
lasting a year and a half to five and a half years, same batteries, same
manufacturer....lots less unrecoverable sulphation.

Boats that have a little charger plugged into the dock and water their
batteries with DISTILLED ONLY get that gravity back up after the abuse of
dreaming you're going to charge them at 50A for 30 minutes on the engine
at sea. Same effect....charging happens very SLOWLY OVER TIME.