Battery equalization

[MarkoPolo]

I have had my 2922KD set up in my yard for about a month and noticed that the charge reading had dropped one light to good, not full. So I spent some time making sure tree branches were cleared above the solar panel and then did the "unthinkable" for guys, read the instructions! It turns out that the Samlex 4 stage controller will either manually or on a set schedule, equalize the battery. I go tho the TM to manually equalize and see that this has been set to a 28 day cycle, was completing it and now I have full charge.
Since I am new to solar panels, I thought this was pretty neat and wondered if this is a common procedure needed on all batteries that are solar charged. Because this does keep the battery on a more even charge level, I also am wondering what the life span for this 27C battery would be and what maintenance should be done.

Mark

[ZekenSpider]

Mark;

Battery charging and long term maintenance is a somewhat complex problem. It has more to do with the charging controller rather than whether it is a solar charger or not.

Take good look at this site and specifically the battery charging information;

<http://www.solar-electric.com/deep-cycle-battery-faq.html#Battery%20Charging>

Your solar controller may or may not be doing a good job.

Jerry

[scrubjaysnest]

Solar charge controllers (cc) typical have a 28 day cycle to equalize. On some this adjustable. Some also come with a manual over ride. Typical CC equalize voltage should be around 15 volts; varies with battery manufactures.

The charge status lights on the panel that shows gray water and fresh water level are only ball park.

The best check is after the battery has rested over night, no load, check the specific gravity of each cell, this will also very between battery manufactures. Draw the elctrolyte slowly into the hydrometer, release it back into the cell repeat 3 or 4 times getting the reading on the last time. The float should not be touch the glass tube and you should always correct the reading for temperature. A good reference source is batteryfaq.org.

[rickst29]

For all SLA batteries which I know of, Equalize should be right around 15.4 Volts.

But many Solar Charge Controllers and Converters with "automatic" Equalization on a schedule use lower voltages - just to play it safe, because you're not there to disconnect the batteries from your TM equipment at 3 AM, when the timer might go off. (15.4 Volts can be tough on Stereo systems, fancy refrigerators, inverters, and and other equipment ).

My Solar Controller doesn't do "automatic", but it does do the full 15.4 Volts. It will only Equalize via pushbutton. I disconnect Battery "+" from the Converter/Load Center, and also disconnect 120VAC from the Converter, to leave the TM equipment "cold" while Equalize is in process. If you do it manually, like I do, you should probably also check your battery cell water levels first, and leave the box covers OFF the battery boxes for the duration of the Equalize Session.

[BrucePerens]

Some controllers set different equalization voltages depending on what sort of battery you've told them you have. So, look at what configuration you can do, and make sure it's right.

Morningstar says to take off the filler caps if you have a battery watering system. The battery might get hot enough to damage them! Their controller will also refuse to equalize if it's already too hot, or if the battery gets to an abnormal temperature.

All of your electrical devices will be powered by the higher-than-normal equalization voltage if you don't do something to disconnect them. Most 12V devices can stand 16V, but there's no sense in stressing them if you don't have to.

Top off the electrolyte after equalization. Some of it will have boiled off.