Equalization reality check

[Calihaze]

Hey everyone. I noticed two things today while running an EQ and I thought I should ask around to see if it's normal or not.

48 volt 840ah battery (16-L16p)

1) It's 50 degress in my powerhouse. The batteries have been on EQ for about 2 hours now, bubbling away. When I touch the top, or sides (6 inches down from the top) of any battery, it's not that warm at all. In fact, I have never witnessed serious heat coming off these guys, even in the summer. I've read about people over-heating their batteries, so I'm curious if perhaps the cold temps up here in the mountains are helping or maybe I'm not pumping enough amps into these...

2) My Outback Inverter and Mate3 are set to EQ at 62.4 volts. However I notice that the battery is always sitting at 62.8 or 63 volts. I check voltage and SG every 30 minutes. Is this an issue at all? I've noticed the mate3 is not very accurate, in general, so perhaps it's just a cheap charger program and this is what I get...

I'm charging with a little propane genny that's putting out 14 amps at 120v AC. I did ensure that the batt was at float prior to EQ. Most SG's started at 1.25 or 1.26 (temp comp). I'm confident that with a few more hours, the SG will get to 2.77 but I'm just wondering if the above indicators might be telling me something.

Added: I should have noted that my house load is <200 watts during the EQ.

Thanks!

[Sunking]

Nothing is wrong, you are just impatient. EQ is not a timed event. It can take as long as 24 hours. What this is telling you is you have been chronically undercharging your batteries for quite some time and not EQ charging often enough.

Quite a number of reasons for this. Mostly following battery manufactures charging directions using 3-stage charging voltage set points. You cannot do that with Solar.Power. It is not that the manufactures are wrong, it is just because they assume you are using a commercial 3-stage AC powered charger. 3-stage charging does not work with solar. There is not enough Sun Hours in a day to completely saturate your batteries.

Go read this and come back with questions. With Solar you set to Maximum Smoke and use your hydrometer to set the only voltage you need. You want 1-stage charging in CC mode.

Lastly, if your batteries get warm to touch while charging, you gotta a big problem on your hands.Anyway keep the EQ on until the SG levels out.

[Calihaze]

Thanks Sunking. So the volt increase is fine too?

Yes, I am impatient sometimes. I try to ensure my batteries hit 1.277 at least once a month. I EQ every month in the winter ; during the summer, as you can assume, I don't have to EQ as often.

It is good to know that the issue is primarily psychological. Thanks!

[Sunking]

Thanks Sunking. So the volt increase is fine too?

Yep no problem. Read the link I gave you. Turn your voltages up in winter to force your controller to stay at full Bulk power from Sunrise to Sunset. Use your hydrometer to determine the voltage set points.

[Calihaze]

Sweet! Thanks SK. I have read that link a few times now, each time picking up more pieces. I understand the basics and I'm practicing them, however I do have some questions, when you have a second.

1) What is the equation for arriving at 62.4 volts for EQ on a 48 volt battery, assuming that we should be applying 2.5 or 2.6 volts per cell? If this is something beyond explaining in this format, don't worry about it.

2) You mention " ...If it is high you should notice gassing and need to lower the voltage..." In other words, I should attempt to reach 100% SOC, at whatever voltage gets me there by the end of the day (assuming I need to be higher than 59.2v), with minimal gassing. Is that right? I suppose this is only for people who cannot reach 100% SOC at 59.2 and then float for the rest of the day...

3) In theory, in an attempt to hit 100% SOC, one might have to bump up their volts from 59.2 to 62, which means the batteries would be gassing and getting damaged prior to hitting 100%SOC every day. Do I assume that if this happens, it means that person should invest in a much larger panel array?

Thanks again. I appreciate the time you guys put into this forum. I live off grid with my family of 5 and this has become a hobby as much as a necessity.

[Calihaze]

Yep no problem. Read the link I gave you. Turn your voltages up in winter to force your controller to stay at full Bulk power from Sunrise to Sunset. Use your hydrometer to determine the voltage set points.

I use a high quality refractometer... as my experience with hydrometers was mixed. I wonder what the preference is for most off-gridders who spend many hours over their batteries...