Float charger for winter

[Rex]

I don't know of any electronic chargers that will bring up a flat battery. When i have one so flat that my new chargers won't work, I get out an old 6-amp manual charger and let it run for about 30 minutes. Then I switch to the microprocessor-controlled charger.

[reggie_obe]

What was the original question.....

[Rex]

"Is the HF float charger worth $9?"

[reggie_obe]

"Is the HF float charger worth $9?"

Exactly! Or, "does it work?".

Not: Gentlemen, please put forth you lengthly dissertation on your own battery chargers that you hold in high esteem.

[spro]

Some of us learn from that and some don't.
If you want direct answer, wade through the net. I'm getting really close to pe'ng you off and that is not my intent nor will it be good for either of us. We, us, have an understanding about the reason for the question and the step after the initial answer. When this all goes away, is not where most want to be.

[reggie_obe]

Some of us learn from that and some don't.
If you want direct answer, wade through the net. I'm getting really close to pe'ng you off and that is not my intent nor will it be good for either of us. We, us, have an understanding about the reason for the question and the step after the initial answer. When this all goes away, is not where most want to be.

What in blazes re you trying to say?
My universal translator seems to be malfunctioning.

[redneckalbertan]

I believe spro is trying to say some people like, enjoy, and learn from the conversation that takes the scenic route. As opposed to the direct path.

[NP317]

I WAS going to offer a brief technical discussion about the "survival" characteristics of lead-acid batteries, but now I'll just watch some more for a while. Very entertaining.
(smile...)
~R

[spro]

I think more information would be useful and interesting, especially now.

[NP317]

I think more information would be useful and interesting, especially now.

OK.
Typical failure modes of lead-acid batteries:

Discharge failures:
Includes "sulfation" of the lead plates due to discharging too much.
As discharge occurs, the sulfuric acid changes to water and sulfur oxide (a non-conductive compound), which can coat the plates, causing the battery to deliver less energy due to the increased resistance on the surface of the plates. Excess sulfur oxides falling off the plates can often be seen as deposits on the bottom of the battery case.
"Glass-mat" batteries are less susceptible to this failure mode due to their different physical design.
Note: There are available modifications to the acid chemistry to limit plate sulfation, and this is what defines a "deep-discharge" battery. Complex stuff for my brain.

Discharged too low, the increased water-to-acid ratio raises the freezing temperature of the acid/water mixture in the battery, making it more susceptible to freezing, which can crack the case = Destroyed Battery. Thus the need to keep them charged during cold weather.

Over-charge failures:

Over-charging of lead-acid batteries causes the acid to electrolytically separate into oxygen and hydrogen, which produces an explosive gas environment around the battery. Pretty exciting results can happen from that! It only requires one small spark... And the cells' acid level will drop too, leading to a decrease in the discharge capacity of the battery. The typical "serviceable flooded-plate lead acid battery" requires periodic addition of distilled water to keep the acid level at the proper height. This need also implies they are being overcharged. Hmmm...

To properly charge a lead-acid battery, the Voltage needs to be monitored to determine when the full charge capacity has been achieved, Then the charger should decrease the current to C/1000, C being the stated Amp-Hour capacity of the battery. The C/1000 rate is what a smart-charger should apply to the battery during long-term storage - like during the present snow storms in the USA! The C/1000 rate may not be sufficient current to re-charge a depleted battery, but it will maintain a charged unit.

So make sure your "smart charger" is actually smart enough to:
- monitor the battery Voltage,
- and adjust the charge current down to a C/1000 rate when fully charged.
Then it can re-charge a depleted battery, and safely maintain a charged one.
And make sure it has the high & low current range to match your specific battery.

Cost is often a factor: True smart chargers have internal circuitry to sense Voltage and adjust output current. These circuits increase the cost of a true Smart Charger.

Please provide any corrections to my comments, in case I mis-stated anything. It happens.
'Hope this helps the discussion on "Float charger for winter."
~Russ

[GlennW]

The only luck that I have had with those chargers (Battery Tender) is to run them on a timer set for 30-45 minutes a day. That's been working very well.

That's how I maintain the battery in my diesel generator

[spro]

Thanks NP and Glenn. This all ties together. Rex also said something which ties it to some experience. The sulfates have to be "boiled", actually bubbled to some point before the float chargers can work. Thanks to all for this discussion. When you put it together, it is very useful.