A Battery Rejuvenator

[Beltman60]

I have 10) 205 watt evergreen's with 32 batteries for 1100 amp/hrs @ 24 volt
this barn is totally off grid including water
I need that much in the winter for bucket heaters, trough heaters and such
in the summer running 5 fans and lights I still have plenty to burn and not get close to 80% battery capacity

 

[King Benjamin]

Yes I had thought the same thing but some how I realized that the charger only worked when connected to a good battery.

Probably, some of you test a battery charger by touching the clips together to see a spark, and if you do, you assume that it is working.

Have any of you came across a battery charger that seem to not put out any voltage? Well I did and thought the charger that I purchased was bad/broke.

A friend of mine showed me something interesting that I did not know. Apparently some battery chargers need some voltage to start the charging process.

The charger reads no voltage not connected to battery, and when connected to battery, it is putting out about 14 V.

Anyway, didn't know if anybody had came across one of these chargers, and thought it was no good, but try connecting the clips on the battery and see if there is any charging voltage.

 

[King Benjamin]

Yes I had thought the same thing but some how I realized that the charger only worked when connected to a good battery.

Probably, some of you test a battery charger by touching the clips together to see a spark, and if you do, you assume that it is working.

Have any of you came across a battery charger that seem to not put out any voltage? Well I did and thought the charger that I purchased was bad/broke.

A friend of mine showed me something interesting that I did not know. Apparently some battery chargers need some voltage to start the charging process.

The charger reads no voltage not connected to battery, and when connected to battery, it is putting out about 14 V.

Anyway, didn't know if anybody had came across one of these chargers, and thought it was no good, but try connecting the clips on the battery and see if there is any charging voltage.

 

[kub0]

As a Bare minimum I hope you are plugging into GFCI. Even then I would be very careful.

 

[King Benjamin]

wow I guess you really need to take care of so many batteries! Has it really been cost effective for you? I mean considering your time also? My son is an engineer in a huge Vault and part of his job is taking care of the battery back up systems. He says at the moment there really is no cost effective way to use batteries for anything but backup situations Where "down time" would mean disaster.

I have 10) 205 watt evergreen's with 32 batteries for 1100 amp/hrs @ 24 volt
this barn is totally off grid including water
I need that much in the winter for bucket heaters, trough heaters and such
in the summer running 5 fans and lights I still have plenty to burn and not get close to 80% battery capacity

 

[Beltman60]

the batteries are sealed AGM type that I got from a guy who gets them from the cell towers
they are to have 10 year life expectancy and they take them off line every 4 years
now these things sit and trickle charge 99% of the time and get used maybe twice a year when power goes out so I din't feel they were hurt in the least bit
these batteries new are $220/each and I got 32 shipped to my place of work to be forklifted off the truck for $1600.
they have been online for 3 years and have lost min capacity (put on line 12.7-12.8 v now 12.6-12.7 v)
now I hardly ever let them depleat passed 80% full charge except in the winter I might let them go to 60% then back feed them with my gen set but that hasn't been an issue since the first year they were online (3 months of 8hrs/ month running gen set)
last year wasn't that cold so bucket heaters weren't needed as much and this year when it was cold the sun was out
I have maybe $5500. total in my set-up and that is about what it was going to cost me to run wire from my house to the barn to get about 30 amp (house is 500 ft from barn)
and I havn't had an electric bill for all my barn power
actually solar is quite boring to have and run
set up and maybe twice a year check some voltages and thats about it

 

[patrick_g]

Has anyone tried using 240VAC in place of 120VAC for the desulfater?

While isolation transformers have merit, so does not touching any bare wires or battery posts while the thing is plugged in. I second the suggestion to use one of these home brew desulfaters with a GFCI outlet. An off/on switch and a pilot light to indicate that power is applied might prevent a shocking experience.

Patrick

 

[patrick_g]

I am wondering why I can't just use a wire wound resistor? And do I measure the cold bulbs and use a resistor of the same ohm reading and at least 3 amps?

To replace the light bulb with a resistor requires an expensive power resistor that handles the same power as the bulb did. Getting the resistance "RIGHT" isn't trivial as the tungsten filament of the light bulb is a non-linear resistance dependent on the temperature of the filament. Measuring it with an ohm meter will not get it right. you need to measure the RMS current through the light bulb with the circuit in operation to calculate the resistor you need. So the question is, why go to all the hassle to eliminate the cheap and effective solution with a more expensive one? If you are using this off road taking lots of high G jolts and vibrations the resistor would survive better than the filament of the bulb but I'll bet it will be used in a static environment.

Do not size the diode by using the current measured flowing in the circuit as a direct indication. The tungsten filament bulb is lower in resistance when cold and will permit an inrush current greater than the RMS current.. To be safe, go for a diode with higher current rating than the average (RMS) current value when the unit is operating.

You could observe this with an O'scope but failing that just go BIGGER in amps.

Pat

 

[TCJatko]

I'm afraid I'd rank this "battery rejuvenator" up there with the perpetual motion machine, the yeti, and the Philosopher's Stone.

 

[patrick_g]

The difference between ignorance and stupidity is that ignorance is capable of being cured by experience and or training/education but stupidity is not fixable.

Lets run a test to see which we are observing. If you look at commercially available professional battery chargers with built in desulfation capability (expensive but work well, not snake oil) you may find that desulfation is not quackery. Pro grade off the shelf circuits use faster rise times (square waves) and some use capacitive discharge to pack extra punch into fast rise time waveforms so may outperform the DIY version discussed here. The issue at hand is not where to rank the DIY version as compared to the commercial models but to acknowledge their similarity and the fact that they do work well enough to make it worth the time to anyone sensitive to paying a lot more $ for a commercial unit.

I know folks who are still waiting for color TV to be perfected before they buy one. Different strokes for different folks. Whether or not someone believes that the DIY circuit in question works or not is immaterial since we have reliable reports that the circuit is working good enough for some of us. Different people react in different ways to things beyond there ken. Some refuse to accept anything beyond their level of technological understanding and that is fine. Limiting but OK. I'm all for the guy who wants to chip out his own folsom points and hunt wild boar with a primitive bow and arrow so long as he doesn't try to convince me that modern rifles are bogus, equivalent to philosopher's stone, perpetual, motion, sasquatch, etc.