My battery soc

Re: My battery soc

I went ahead and set it for another three hours.
gww

Re: My battery soc

Blackcherry
On the rest helping, I hope so.

Hot water heater in use.

The way it was. I had the absorb voltage set at 61.2 volts. The sun would come out and build the voltage to about 58.5 volts and then the charge controller would actvate a ssr that would allow the power from my sub-panel to get to the hot water heater. This is the sub-panel that my critical loads are on through the inverter. It will start buy turning on like 1 to 3% of the hot water heater draw. As the battery at 58.5 volts started requirering fewer amps or the sun became stronger on the panels, the percent the hot water heater was allowed to increase till eventually it was to 100 % or 2000 watts. The affect is that the battery stays at 58.5 volts for anywhere from an optimistic 30 min till at the most an hour and a half at about the longest. When I hit this voltage the sun is usually still increasing in intensity and I would say an average of 45 min at 58.5 volts before allowing the battery to get to 61.2 which could take 15 more mins to go from 58.5 volts to 61.2 volts.

I have changed the absorb to 60 volts and set the opertunitie load to kick on at 59.5 now. Also, sometimes the hot water is full before absorb has ended which extend absorb ad the sun goes down. Other time if I need a charge I will disable the hot water as the sun goes down so absorb is extended as long as possible. I kind of looked at the high voltage the battery was sitting at as a sort of pre-absorb as even when the hot water kicked in, the battery for that 30 min to an hour and a half was higher then my old absorb rate.

I ran it all day while eq, cause the solar was having no problim doing both and holding eq voltage and still cutting prodution.
As bill always says, clear as mud, right.
gww

Re: My battery soc

Blackcherry
My problim is I am compleetly paranoid. The same thing that is a fix for one battery is the killer from another. The info from the battery makers them selves is contradictory sometimes on the same sheet. I have spent an unbelievable amount of time sitting and watching gauges. How the sun behaves on a certain day. Checking sgs every half hour for days at a time to see how they react to each situation. looking at the turbines compared to the wind. Knowing since I bought it, the battery sgs weren't that good and not knowing if I was helping or hurting with my actions. days of watching, getting the cc's to play well with each other. That makes changing settings scarry cause then you got to watch again to see if it still works as good as it did. I am not complaining but at times feel a bit inept. I really am proud of every success though.

I am retired so the busyness isn't that bad but the mistakes hurt worse cause I don't make as much money as I used to to make up for them.

I still enjoy my little projects and a couple of these forums have made it so this highschool dropout still has a chance of learning and mayby being succesfull. I am the only system I have ever had a peak at.
gww

Re: My battery soc

Thank coot
I am figuring out where to look. Gonna be a late night. I will check the sgs write it down and water and then put loads on it. At what amp from full level should I check the sgs to make sure I don't go to low in case I have lost a bunch of capasity? 640 amps would be the 80% mark but I sure don't want to go there and find that is 100% discharge. Maby 500 amps out and check the sg? No matter what if history is an indicator I should be safe with the inverters settings once but when I put it back on after low voltage disconnect it would be a little more scarry. I intend to watch very close if I can.

Thanks
gww

Ps amp from full or to full (how ever it is writen) should be correct if I have no charging going on, right?

Re: My battery soc

Quote from me
If the meter does nothing else I should get an ideal, running with no charging, of what is taken out of the battery and what the battery looks like sg wise based on the amps used.

Man I screwed that up. I should have added water half way through the eq cause my sg reading are now going to mean nothing untill I charge and mix again. duh.

CALLD

Yes because of the price of them and all the info out there, batteries are hard in my book. I had pretty much given up on trying to worry about the few low cell sg cause I had worked and never been able to do anything about it. Sombody said something here that made me think it was worth another plan to try one more time, by cycleing low and re-charging a couple of times. I figured what the heck, and by doing so I might also just see where the battery was at as far as capasity goes. Sorry to here about you battery problims and good luck next time.

Bill

I had pretty much given up on ever getting my sg's to read proper and had gone to just letting the outback setting and solar do what they wanted for about ten days and then disconecting the loads to garentee I got a full charge. It was much less stressful although I am a worryer and very seldom let them go for ten days. I have used not quite 1and1/2 gal water per month since new. I read the rolls battery link that blackcherry posted it metioned that if you had to add water every month you were over charging. I don't have any ideal how, close or far, in simularity a rolls battery is to mine. It also said if you under charge for a bit that your voltage will be false high causing your charging to be inatiquit due to the cc cutting back amps based on voltage.

I wrote on anouther forum that I always felt I was ruining the battery cause I was under chargeing and overchrging at the same time.

Needless to say, the last week of overcharging has brought my low cell from the old high of 1.272 to a new of 1.282.

I am going to stick with coots suggestion and take the battery low and recharge a few times and see what happens. I have the new meter and even though I screwed up this time and won't get good sg readings, I can still look at the trimetric and see how many amps are removed compared to voltage. If I do it twice I should see sg comared to load removed from battery. Hopefully on this discharge test I will find my battery is not hurt, not that I can do anything if it is hurt. If is isn't hurt then maby the way I use it isn't to bad, If it is hurt I don't know what to change.

I have always felt I might be overcharging trying to get the sgs up. In the end if I can't learn anything I wil probly go back to the less stressful, run ten days then garrentee a charge.

I do eq once mothly cause that what the battery maker wants, and keeps my eye on water. I don't know if while doing this, I am over charging to get an sg up that is not going to come up.

Batteries are kind of hard.
Cheers
gww

Re: My battery soc

12 hours has took 171 amps from the battery so far. Under load the battery is at 49.3 voltage.
gww

Re: My battery soc

Blackcherry
I want to get as much as I can but not at the expence of the battery.

I am at about 240 amps out now and the battery 48.6 volts with a 410 watt load on it (about 8.3 amps). The mate says I am drawing only 100 watts. I would say the mate is usually way off.

I have seen simular stuff on charging with the cc reading much higher then the mate.

I saw the battery at 47.5 volts with about a 30 amp draw on the battery which is why my low voltage disconnect is so low. Big loads draw the voltage down alot on these/this battery but don't reflect that they are really that low or have used that much power. It is back to the 48.6 when the amp load drop to 8 amps.

I realize the low voltage disconnect setting could bite me some day if I get to it with a very low load.

I am still wondering how far I should push the discharge. If I take the battery down to 640 amps used and it has lost some cappasity it could be too much and cause permanate damage. I guess I will play it by ear and hope I get it correct.
Thanks
gww

Re: My battery soc

Blackcherry
I re-looked at my last post and the one thing that might not be clear is that when I metioned the low voltage at 46 volts, it was something that I had tried and didn't work so I have it set at 44.8 volts for 6 min. and it works well and when it does disconnect my batterys always rebound to between 48 to 48.8 volts. Also when it disconnets the cc usually shows that my low voltage for the day was 45.7 volts. I don't find this discrepency that disturbing cause I never end up taking the batteries below 50% with the way it is working. The only real issues might be that I didn't take the battery low enough for the best forming of the plates altough I am not sure of that as my sg readings have had the batteries below the 50% level a couple of times. I still think over all I am a bit higher then 50% and maby closer to 65% charged most times I reach low voltage cut off.

How to put the voltage readings at 50% and sg lower a couple of time. I can only guess that the few low sg times had more to do with maby getting lower charging/defacit charging worse a couple of times that were not normal. I am not sure.

I did make it through last winter and what I noticed was an over all lower average production but much higher charge rate when the sun was shinning. I added a couple months winter and believe I had a 16kwh day average with my high production days being 30kwh and above but more overcast days. My summer daily average was more like 20 kwh daily but I had many more high days that only produced 26kwh but more of them due to fewer overcast days. I just run my loads on grid during bad times or times I get behind on getting a good charge.

The biggest risk I see with the voltage sag is if I were gone and no one flushed a toilet. A small 400 watt load durring a time like that might take the batteries lower then they should be. The way it has acted so far I believe that at 44.8 a fridge kicking on will still keep it above 80 % discharge (i hope) I don't get the 45.7 low voltage on the cc when I disconnect but maby there is a default setting or setting I am missing that would save me from going to low. So far the battery is 48 volt or above when I disconnect. We will see soon while I try to discharge further.

Vic
I agree, not much head room on the water, two gal is about the limit before real danger. Maby thats why the battery make want an eq every month. Maby that is their way of making sure you look at the battery often enough.

Thanks
gww

Re: My battery soc

Update
The loads lasted untill morning when I used water. I went and reset. The low voltage on the cc was 44.7. I increased the low voltage disconnect to 12 min at 44.8. I went back out at 6:30 am and the loads had switched to grid again. The trimetric has the battery at 47% charged. The cc had started a new day and the low voltage on it was 45.7. The battery voltage was 47.3 volts and I am sure it was not resting very long. It is 32 hours since I put the loads on. The trimetric say I have used 421 amp hours from the battery. I set the low voltage time value to 44.8 volts for 18 min.

It looks like I am going to lose some morning sunlight cause I am still drawing the batteries down.

Resting voltage for 80 % discharge should be around 46.3 volts unless I am wrong.

Any thoughts so far?

Thanks
gww