My battery soc

Re: My battery soc

Question
If the low cell sg gets to 80% discharge before the rest do should I stop and recharge?
Thanks
gww

It is 1.190 sg now at the battery monitors 69% The high is 1.200 which you would think to be about 50% discharge.

Re: My battery soc

Blackcerry
low cell is cell 24.
Records so far.

Per trimetric = 88% full, 31 amp draw, voltage under load 49.2, temp 76.9 degree f, 99 amps taken from battery
sg cell 8 = 1.261, cell 24 = 1.249

79% full, 33.4 amp draw, v under load 48.6, temp 77.4 d-f, 169 a taken from battery
c8 =1.239
c24 = 1.220

69% full, 23.3 amp draw, v under load 48.2, temp 75.8, 245 a taken

c8 =1.205
c24 = 1.190

Thank you for you answer
gww

Re: My battery soc

There is a chart around page 12 of this thread that shows 1.200 as 50%, I will look again. The problim is they sent a charging paper that says 1.170 is 80% discharge and the chart shows 1.145 to 1.50 as 80% . I think I should probly go with the paper they sent me with the battery.

gww

The chart show 1.150 to 1.165 as 80 % discharge battery paper shows 1.170 as 80% discharge.

Re: My battery soc

47.4 volts is half way above 40% to 50% and 48.4 is half way from 60% to 50%. Over all the voltage seems to be tracking with the discarge rate and with what the trimetric reports. The trimetric may be reporting 5% to 10% high per voltage depending on weather the chart is for loaded voltage or resting voltage. The sg does not match the voltage and is much lower across the board even on the high cells (I think).

gww.

I went so much lower last time it sort of makes me want to try for at least 50% on the trimetric but the low cell sg is already at the paper low and honestly the high on the chart, both numbers is already at 80% discharge.

Thanks
gww

Re: My battery soc

calld
I don't mind going low on the voltage but since I have lead acid and can check and the battery came with a paper that said that is what I should check, thats what I do. The sg should be higher with that voltage.
gww

Re: My battery soc

One other thing that could be a small effect is, the trimetric draw is about 6% less then the clamp meter says is leaving the battery, but that still means that it the meter said 318 amps the truth might be 337 amps. It still wouldn't make 60% discharged an 80% discharge. puerkt might but only if it affects sg much more then it does voltage. The only thing I have read that act that way is stratifacation or low cell from factory dragging the others down (though in that case you would think it would affect voltage also) I kind of wish coot would chime in on the voltage to sg differance.

Thanks
gww

Re: My battery soc

calld
What I know is I have no ideal. I am hoping by posting what I see, that people who do have an ideal keep telling me what it means, weather it is good or bad and how to counter it if it is bad. If I am supposed to be looking for other things also I hope I am clued in.

The battery is at 1 hour absorb, is a little over 80 degrees, The sg on low cell is 1.259 and the battery is at the 2% amp rate and is only accepting 16.4 amps. The trimetric has the battery full at 17 more amps. The clamp meter says the amps going into the battery is 6 amps higher then the trimetric is reporting. some of that is probly supposed to happen due to it putting in more then it takes out, due to internal efficiancy level settings.

Now you know as much as I do.
Cheers
gww

PS I have been using the batteries from 9-22-2013. ps-ps I have put about 18kwh back to the battery per cc ps-ps-ps all the cells had the same water level after charging to this point, It is almost as if you could tell the bad cells by water level cause at the end of discharge some had not moved and some were lower, still very hard to see how much lower with out sticking something in the cells which I did not do.

Re: My battery soc

Update; 10-25-2014 at 11:26 am.

Trimetric had battery as 56% charged, Voltage under load 47.2 volts, 30 amp draw, 347 amp hours from battery per trimetric, Temp 74.9 degrees.

Low cell sg 1.155, battery rebounded to 48.2 volts pretty quick.

I did not check the high cell but had checked them at 50% (should say 60%, typed wrong number) discharge on trimetric. They were 1.180 high and 1.170 low. I was trying to take the low to 1.165 but apparently misjuged how long that would take, ergo the 1.155.

I also did a bit of expermenting with the volt meter but don't trust the readings so I probly shouldn't mention it but will anyway.

I tried to check the cell voltages per cell around the bad cell. It seemed that the low cell was .8 volts and the high cells where 1.95 to 1.97 volts. the reason I am not sure of the reading is cause when I tilted, twisted and sraped the leads touching the low cell I could get a 1.95 volt reading but it did jump around alot of time also. I was just checking through the hole in the platic safety covers. I may need to remove a couple and try harder.

Would a meter be a load that would stableize the voltage of a single cell with help from the surrounding cell?

I also screwed up cause I forgot to turn the pv off and woke up late for the second time in a couple years. I must have been wiped out from yesterday. I didn't get to the battery till 8:30 this morning and it was carrying the loads with solar at that time. I turned the solar off and completed the discharge.

Does anyone have any toughts on my documentation so far and what direction I am heading in so far?
Thanks
gww