I was told that a car battery wouldn't last long anyway for this
application, so even when my car battery is 6-7 years old, it
wouldnt't last more than a year when trickle charged, while it is far
better economy to buy a leisure type battery
====
A leisure type (deep cycle) battery is fine for a moderate load for a
relatively long time ,since the plates are relatively thick.
However they are not suitable for engine starting purposes ,since brief
demands for a high starting current cannot be met reliably over time.
That's why car batteries have relatively thin plates with a large area
capable of supplying the high starting current.

If a car is kept outdoors it is worthwhile employing a small solar panel
positioned near the south face of the car with its lead plugged into the
cigarette lighter socket. This will keep the battery in a healthy condition.
I have seen these solar panels advertised by the car accessories trade.

Frank GM0CSZ / KN6WH

Frank Dinger wrote:

I was told that a car battery wouldn't last long anyway for this
application, so even when my car battery is 6-7 years old, it
wouldnt't last more than a year when trickle charged, while it is far
better economy to buy a leisure type battery
====
A leisure type (deep cycle) battery is fine for a moderate load for a
relatively long time ,since the plates are relatively thick.
However they are not suitable for engine starting purposes ,since brief
demands for a high starting current cannot be met reliably over time.
That's why car batteries have relatively thin plates with a large area
capable of supplying the high starting current.

If a car is kept outdoors it is worthwhile employing a small solar panel
positioned near the south face of the car with its lead plugged into the
cigarette lighter socket. This will keep the battery in a healthy condition.
I have seen these solar panels advertised by the car accessories trade.

Frank GM0CSZ / KN6WH

================================================== ===========

In the past I've maintained car batteries for many months using a small
(2" x 8") solar panel made for this purpose.

How much current could this put out? I don't know but I'm sure it's not
much. Nowhere near one ampere. It contained a diode and no voltage
regulator. This is the same effect I want to achieve with a small wall
wart.

If it's safe to float charge the battery at .01 C indefinitely, say 700
mA for a 70 AH car battery, then anything under 700 mA is also safe. My
200 mA wall wart is safe.

The question then is what is the self discharge rate, less things like
an alarm and clock?

Frank Dinger wrote:

I was told that a car battery wouldn't last long anyway for this
application, so even when my car battery is 6-7 years old, it
wouldnt't last more than a year when trickle charged, while it is far
better economy to buy a leisure type battery
====
A leisure type (deep cycle) battery is fine for a moderate load for a
relatively long time ,since the plates are relatively thick.
However they are not suitable for engine starting purposes ,since brief
demands for a high starting current cannot be met reliably over time.
That's why car batteries have relatively thin plates with a large area
capable of supplying the high starting current.

If a car is kept outdoors it is worthwhile employing a small solar panel
positioned near the south face of the car with its lead plugged into the
cigarette lighter socket. This will keep the battery in a healthy condition.
I have seen these solar panels advertised by the car accessories trade.

Frank GM0CSZ / KN6WH

================================================== ===========

In the past I've maintained car batteries for many months using a small
(2" x 8") solar panel made for this purpose.

How much current could this put out? I don't know but I'm sure it's not
much. Nowhere near one ampere. It contained a diode and no voltage
regulator. This is the same effect I want to achieve with a small wall
wart.

If it's safe to float charge the battery at .01 C indefinitely, say 700
mA for a 70 AH car battery, then anything under 700 mA is also safe. My
200 mA wall wart is safe.

The question then is what is the self discharge rate, less things like
an alarm and clock?

mcalhoun wrote:

I need to store a car unattended for a winter in the midwest. And I
want to put a tricke charge on the battery.
....[snip]....

Although their normal price is about $15, float battery chargers (wall
wart, coiled cord, little black box with LED, two cords with large
alligator clips on the ends) are often advertised in Harbor Freight
catalogs for $7.99. I must have half a dozen of them now, keeping
batteries here and there up to snuff. I've never measured them, but
they seem to do a real good job, and they're hard to beat at that price!

I have no connection to Harbor Freight except as a satisfied customer,

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

================================================== =====

You don't say! Have you ever measured their voltage? Or is it written
on the case?

mcalhoun wrote:

I need to store a car unattended for a winter in the midwest. And I
want to put a tricke charge on the battery.
....[snip]....

Although their normal price is about $15, float battery chargers (wall
wart, coiled cord, little black box with LED, two cords with large
alligator clips on the ends) are often advertised in Harbor Freight
catalogs for $7.99. I must have half a dozen of them now, keeping
batteries here and there up to snuff. I've never measured them, but
they seem to do a real good job, and they're hard to beat at that price!

I have no connection to Harbor Freight except as a satisfied customer,

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

================================================== =====

You don't say! Have you ever measured their voltage? Or is it written
on the case?

Keeping the battery charged is not the only reason to start the car once
a week.

Suppose it means that a car battery won't last long if you keep it
steady at top charge level, instead of decharge it down towards 50%,
....[snip]....
I was told that a car battery wouldn't last long anyway for this
application, so even when my car battery is 6-7 years old, it
wouldnt't last more than a year when trickle charged, while it is far
....[snip]....

I understand that battery electrolyte becomes stratified if the batteries
don't receive the shaking they would normally get through vehicle motion
OR by charging hard enough that the electrolyte "boils" enough to mix
itself up.

I do know that the batteries I've used to power all of my 'shack radios
for the last 25 years do NOT last any longer (as I thought they would)
in a quiet/protective environment than the same batteries I put in my
vehicles!

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

Keeping the battery charged is not the only reason to start the car once
a week.

Suppose it means that a car battery won't last long if you keep it
steady at top charge level, instead of decharge it down towards 50%,
....[snip]....
I was told that a car battery wouldn't last long anyway for this
application, so even when my car battery is 6-7 years old, it
wouldnt't last more than a year when trickle charged, while it is far
....[snip]....

I understand that battery electrolyte becomes stratified if the batteries
don't receive the shaking they would normally get through vehicle motion
OR by charging hard enough that the electrolyte "boils" enough to mix
itself up.

I do know that the batteries I've used to power all of my 'shack radios
for the last 25 years do NOT last any longer (as I thought they would)
in a quiet/protective environment than the same batteries I put in my
vehicles!

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

Harbor Freight $7.99 float chargers:

You don't say! Have you ever measured their voltage? Or is it written
on the case?

I never had, so I went out (to the garage; brrrr!) and measured one:
13.58 volts. FWIW, the wallwart says "15VAC at 600 ma", but there's a
little plastic box on the wires between the wart and the battery clips.

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

Harbor Freight $7.99 float chargers:

You don't say! Have you ever measured their voltage? Or is it written
on the case?

I never had, so I went out (to the garage; brrrr!) and measured one:
13.58 volts. FWIW, the wallwart says "15VAC at 600 ma", but there's a
little plastic box on the wires between the wart and the battery clips.

--Myron.
--
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTX). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

On Wed, 05 Nov 2003 18:09:46 -0500, Bruce W...1 wrote:
mcalhoun wrote:
Although their normal price is about $15, float battery chargers (wall
wart, coiled cord, little black box with LED, two cords with large
alligator clips on the ends) are often advertised in Harbor Freight
catalogs for $7.99. I must have half a dozen of them now, keeping
batteries here and there up to snuff. I've never measured them, but
they seem to do a real good job, and they're hard to beat at that price!

I have no connection to Harbor Freight except as a satisfied customer,

Ditto to all of the above.

You don't say! Have you ever measured their voltage? Or is it written
on the case?

Mine vary between 13.5v to 13.6v. If you open the little plastic
box between the transformer and the battery terminals you will find
a little adjustment that will let you tweak the voltage.

I have two different styles, one with curly coiled leads and one
with straight leads. I think the straight lead is older and has
been obsoleted. Too bad, because they made a nice low-current
adjustable power supply. The curly lead ones don't. But they
both seem to do a fine job of keeping lead acid batts up to snuff.

I have a couple on my bench. One set to 13.6v and one to 14.1v. I
put a gel cell on the 14.1v to charge after use, then on to the
13.6v to maintain ready for next time.

I have one in the barn. I cut off the clamps and put on a pair of
anderson powerpole connectors. A matching connector on my lawn
tractor allows me to easily attach with no concern for polarity
mismatch whether it is me or anyone else. I got 5 seasons from the
last battery, which is pretty good for a lawn tractor that sits
pretty much unused october thru april.

sdb
--
| Sylvan Butler | Not speaking for Hewlett-Packard | sbutler-boi.hp.com |
| Watch out for my e-mail address. Thank UCE. change ^ to @ |
It may be better to live under robber barons than under omnipotent moral
busybodies. The robber baron's cruelty may sometimes sleep, his
cupidity may at some point be satiated; but those who torment us for our
own good will torment us without end, for they do so with the approval
of their consciences. -- C. S. Lewis