charging lead-acid batteries

[Josh Wyatt]

I got a good deal on some 12v 22AH lead acid batteries.

Until I come up with some good projects, I'd like to keep these in top health.

I get the impression from this wikipedia article:

http://en.wikipedia.org/wiki/Lead-acid_battery

....that I should be able to float these at 13.8 volts or so, indefinitely...

Thoughts? It would be trivial to whip up a well-regulated 13.8volt power supply.

Thanks,
Josh

 

[Pooh Bear]

I got a good deal on some 12v 22AH lead acid batteries.

Until I come up with some good projects, I'd like to keep these in top health.

I get the impression from this wikipedia article:

http://en.wikipedia.org/wiki/Lead-acid_battery

...that I should be able to float these at 13.8 volts or so, indefinitely...

Thoughts? It would be trivial to whip up a well-regulated 13.8volt power supply.

The article seems to suggest 13.2V actually.

Graham

 

[Stanislaw Flatto]

I got a good deal on some 12v 22AH lead acid batteries.

Until I come up with some good projects, I'd like to keep these in top
health.

I get the impression from this wikipedia article:

http://en.wikipedia.org/wiki/Lead-acid_battery

...that I should be able to float these at 13.8 volts or so,
indefinitely...

Thoughts? It would be trivial to whip up a well-regulated 13.8volt
power supply.

Thanks,
Josh

No! Direct current long term charging creates a chemical reaction on
plates disabling in depth penetration of the desired action.
For best effect it is better to use fully rectified AC woltage with
proper size limiting resistor to limit the heating effect on battery.
When the charging wave drops below battery voltage this relax allows the
chemical penetration to dig deeper into plates.
(Lead-acid behave differently then Ni-Cd, and should be treated
differently in long term usage)

HTH

Stanislaw
Slack user from Ulladulla.

 

[Ian Stirling]

I got a good deal on some 12v 22AH lead acid batteries.

Until I come up with some good projects, I'd like to keep these in top health.

I get the impression from this wikipedia article:

http://en.wikipedia.org/wiki/Lead-acid_battery

...that I should be able to float these at 13.8 volts or so, indefinitely...

Thoughts? It would be trivial to whip up a well-regulated 13.8volt power supply.

Theyare likely to be significantly reduced in capacity in well under 5
years in any case.
If you keep them in the cold, it helps.
Keeping fully charged in the freezer would be the best bet, but not
very practical.
I would expect them to last 10 years easily.

 

[Boris Mohar]

No! Direct current long term charging creates a chemical reaction on
plates disabling in depth penetration of the desired action.
For best effect it is better to use fully rectified AC woltage with
proper size limiting resistor to limit the heating effect on battery.
When the charging wave drops below battery voltage this relax allows the
chemical penetration to dig deeper into plates.

This is really interesting. Do you have any more information or a link to
this?



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

void _-void-_ in the obvious place

 

[Dave Holford]

No! Direct current long term charging creates a chemical reaction on
plates disabling in depth penetration of the desired action.
For best effect it is better to use fully rectified AC woltage with
proper size limiting resistor to limit the heating effect on battery.
When the charging wave drops below battery voltage this relax allows the
chemical penetration to dig deeper into plates.
(Lead-acid behave differently then Ni-Cd, and should be treated
differently in long term usage)

HTH

Stanislaw
Slack user from Ulladulla.

I'm very interested in this subject, but the term "fully rectified AC" is
unfamiliar.
My initial reaction is that this means DC, or is it meant to imply full wave
rectification? I would think that half wave rectification with no smoothing
would better provide the "charging wave drops below battery voltage".

I would be interested in more details since I have both conventional
lead-acid and gell-cells which I use as backup power sources and most of the
information I have read has recommended a DC float charge - any information
on what I can do to extend their useful life would be most welcome.

Dave

 

[ehsjr]

Stanislaw Flatto wrote:




I'm very interested in this subject, but the term "fully rectified AC" is
unfamiliar.
My initial reaction is that this means DC, or is it meant to imply full wave
rectification? I would think that half wave rectification with no smoothing
would better provide the "charging wave drops below battery voltage".

I would be interested in more details since I have both conventional
lead-acid and gell-cells which I use as backup power sources and most of the
information I have read has recommended a DC float charge - any information
on what I can do to extend their useful life would be most welcome.

Dave

I don't know if there is a "definitive answer" as to *the*
best way to charge lead-acid batteries. Float charge is
fine, but you don't need to make it indefinite, which seemed
to be the issue. Cycle it on/off - say 1 hour per day.

Ed

 

[Stanislaw Flatto]

Dave Holford wrote:

I'm very interested in this subject, but the term "fully rectified AC" is
unfamiliar.

May I introduce: Either a center taped secondary of a transformer with
the center connected to reference and two diodes on windings.
Or single winding connected to diode bridge with one output connected to
reference.
Both will produce half sinusoidal waves from reference in one polarity
twice the frequency of mains.
(No smoothing!!)

I would be interested in more details since I have both conventional
lead-acid and gell-cells which I use as backup power sources and most of the
information I have read has recommended a DC float charge - any information
on what I can do to extend their useful life would be most welcome.

Dave

Sorry this information is from memory, the research I was involved on
this subject was done in late '70s.

HTH

Stanislaw
Slack user from Ulladulla.

 

[Michael A. Terrell]

May I introduce: Either a center taped secondary of a transformer with
the center connected to reference and two diodes on windings.
Or single winding connected to diode bridge with one output connected to
reference.
Both will produce half sinusoidal waves from reference in one polarity
twice the frequency of mains.
(No smoothing!!)


Sorry this information is from memory, the research I was involved on
this subject was done in late '70s.

HTH

Stanislaw
Slack user from Ulladulla.

The term is "Full Wave Rectification"


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Dave Holford]

The term is "Full Wave Rectification"

That is the term I used in the paragraph that Stanislaw edited out.

Dave

 

[Michael A. Terrell]

That is the term I used in the paragraph that Stanislaw edited out.

Dave

Sorry, I didn't see that message. My news server is losing a few
messages right now. I get the header, and a message not found error
when I click on them.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Dave Holford]

Sorry, I didn't see that message. My news server is losing a few
messages right now. I get the header, and a message not found error
when I click on them.

Me too - a real pain.