Alright, so I built a voltage regulator with parts that I have around,
an LM7812 with a few diodes connected to a 500 mA 12VDC wall wart. I
hope you guys are happy now.

What sort of open-circuit voltage are you getting out of it?

However I still maintain that a properly sized wall wart could do the
job with no voltage regulation.

Hey, it's your battery (or your neighbor's) - if you want to
experiement and see if you can figure out whether that sort of
charging regime will appreciably shorten the life of the battery, go
for it!

I just figure that doing the job right isn't really very much harder
than doing it "maybe right, or maybe we shorten the battery's life by
a year?".

[and I really do like the idea of those Harbor Freight float chargers...
$7.95 for a tweakable-voltage half-amp charger is so low I don't
see much sense in homebrewing my own any more! I'll have to pick up
a couple.]

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Bruce W...1" wrote in message
...
Alright, so I built a voltage regulator with parts that I have around,
an LM7812 with a few diodes connected to a 500 mA 12VDC wall wart. I
hope you guys are happy now.

However I still maintain that a properly sized wall wart could do the
job with no voltage regulation.

Hey, you came to the group asking for help. It has been dispensed by
several responders who, by all indications, know and understand the
technology of batteries and charging much better than you. I've said to
several others like you, and I'll extend the advice to you as well... "If
you can't live with the answer, don't ask the question".
The responses to your question have been pretty much "spot on" correct. If
you don't want to take the advice of those who offered you help, then please
leave and revel in your own obstinance.
If you had taken the time to use the web and done a bit of research into
batteries and proper charging techniques, you would have saved several
helpful people a bit of wasted effort on your behalf.
Cheers....
--
Tweetldee
Tweetldee at att dot net (Just subsitute the appropriate characters in the
address)

Never take a laxative and a sleeping pill at the same time!!

"Bruce W...1" wrote in message
...
Alright, so I built a voltage regulator with parts that I have around,
an LM7812 with a few diodes connected to a 500 mA 12VDC wall wart. I
hope you guys are happy now.

However I still maintain that a properly sized wall wart could do the
job with no voltage regulation.

Hey, you came to the group asking for help. It has been dispensed by
several responders who, by all indications, know and understand the
technology of batteries and charging much better than you. I've said to
several others like you, and I'll extend the advice to you as well... "If
you can't live with the answer, don't ask the question".
The responses to your question have been pretty much "spot on" correct. If
you don't want to take the advice of those who offered you help, then please
leave and revel in your own obstinance.
If you had taken the time to use the web and done a bit of research into
batteries and proper charging techniques, you would have saved several
helpful people a bit of wasted effort on your behalf.
Cheers....
--
Tweetldee
Tweetldee at att dot net (Just subsitute the appropriate characters in the
address)

Never take a laxative and a sleeping pill at the same time!!

"Bruce W...1" wrote in message ...
This is not ham radio related but I know you guys have the answer.

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

I'd rather not buy a fancy trickle charger because it would probably get
stolen. On the other hand I have a vast array of wall wart
transformers.

If I connected one of these transformers how many milliamps should it
put out at 12V? Or rather what's the least current that would do the
job?

It seems that lead acid batteries can dissipate too much current as
heat. In other words I could probably feed it one amp continuously.
But would 100 mA at 12V do the job? I'd hate to lose a 1-Amp wall wart.

Thanks for your help.

Hi Bruce,
you have been given heaps of technical suggestions, heres mine.

1.Pull the battery out of the vehicle and take it back to your place.
2.Every week or so, check specific gravity with a hyrometer (sp) and
if it needs charging, do so.

This solves the problem of someone stealing the car unless they are
really keen, is simple, easy, and lo tech.

73 de VK3BFA Andrew

Alright, so I built a voltage regulator with parts that I have around,
an LM7812 with a few diodes connected to a 500 mA 12VDC wall wart. I
hope you guys are happy now.

However I still maintain that a properly sized wall wart could do the
job with no voltage regulation.