papa
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Posts: 7
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Post by papa on Mar 2, 2018 17:51:54 GMT -8
What screen would you view to know your battery power level?
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Post by rabird on Mar 2, 2018 18:06:56 GMT -8
I look at battery voltage 1st thing in the morning when there is no charging or load.
I consider 12.2v ~50% which I try not to go below.
12.3 ~60, 12.4 ~70, 12.5 ~80, 12.6 ~90 and 12.7 ~90.
During charging the voltage goes up to mid 14v and stays there for a while so there is no way to know, even med 14v the battery could be 80%, 90% or near 100%, it is impossible to tell.
Under a load the voltage drops so that voltage can mean nothing. A big load drops the voltage more!!.
These controllers have a State of Charge algorithm (SoC) which is meaninless as best I can tell!
Then there is temperature which changes everything!
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papa
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Post by papa on Mar 2, 2018 18:25:52 GMT -8
I know that's what I'm trying to understand. If soc means nothing why is it on the screen. I've already come to terms about it. All I'm looking for is an indication as to when I should shut down. What screen in the veiwsrar can help? Thanks
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Post by tattoo on Mar 2, 2018 18:32:26 GMT -8
I know that's what I'm trying to understand. If soc means nothing why is it on the screen. I've already come to terms about it. All I'm looking for is an indication as to when I should shut down. What screen in the veiwsrar can help? Thanks I don't have or ever used a viewstar.. What I would suggest is what ever screen that shows the voltage of the battery is the one I would choose... If that's what you are asking... |
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Post by tattoo on Mar 2, 2018 18:46:35 GMT -8
These controllers have a State of Charge algorithm (SoC) which is meaninless as best I can tell! Bird all BS aside... Why do you think the SOC is there at all... Before I decided that it means nothing I tried to understand it... It changes with every little draw, charge everything is a variable.... So it doesn't make an sense at all... Since you have a way to look at it as a graph or do you, what does it look like?  ?? |
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papa
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Post by papa on Mar 2, 2018 19:03:09 GMT -8
I do not. Rep from Papa. The view star shows volts and amps delivering from PV. Volts and amps going to battery from PV. Other than that I have no way of knowing what state my batteries are. Sorry Tattoo I told I'm OCD. Ribird thanks form comments. Please keep it coming. Should I invest in a mt5o? Would that give this Oldman the numbers?
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Post by tattoo on Mar 2, 2018 19:26:57 GMT -8
I do not. Rep from Papa. The view star shows volts and amps delivering from PV. Volts and amps going to battery from PV. Other than that I have no way of knowing what state my batteries are. Sorry Tattoo I told I'm OCD. Ribird thanks form comments. Please keep it coming. Should I invest in a mt5o? Would that give this Oldman the numbers? Yes sir buy a MT50... I had one of them with my 40a CC and it was great... Not as good as my 60a CC commander but it was almost as good... |
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Post by rabird on Mar 3, 2018 5:19:28 GMT -8
On a 12v system and PWM, pv volts should be about the same as battery volts during bulk charging. During boost (aka absorptiion) PV volts displayed will be greater than battery voltage, during boost the controller connects and disconnects form the battery very fast to limit power to the batt to maintain say 14.4v (or 14.8v!). this on time and off time varies, the on times get shorter and the off time longer to taper power to batt as the current tapers cuz the controller is trying the keep the batt @ say 14.4v. The batt can not take as much power without the voltage rising as it gets fuller and fuller. The on time, PV volts = Batt v, or 14.4v. during the off time pv volts=Voc (~20v). There is no power @ Voc when ya measure a panels voltage with no load. Below is my visulization of 50% on / 50% off from a 4A panel yielding 2A and an average PV volt of Voc and batt v, as current tapers the PV volt display will rise to almost 20v!  A battery monitor has a lot more 'brain' than the SoC displayed on these controllers, it account for energy into the batt and energy out of the battery and has some logic of how much extra in is needed to get back to 100%, say 120%., and reset from time to time when the batt is FULL. You need to become the battery monitor, how different loads lower the batt v differently ... Dynamic system changing all the time! In any event ya want to FULLY charge the batt regularly for long life, ideally daily but at least ever couple days or so. This may mean you have to limit use, charge from another source or whatever it may take. resting voltage is an estimate of SoC. and that means charging or discharging batt v only means something to YOUR gray matter after some observation cuz just a voltage reading is meaningless not know how much load or charge may be going on. |
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Post by rabird on Mar 3, 2018 5:43:14 GMT -8
at one time I had a 10A viewstar and with a cable and PC used the software to capture the below, if ya look close ya see PV and Batt V are the same until batt V get to 14.4v and then PV volts goes up as this on/off process starts/continues, ya can then see the controller go into float of 13.?v and the on/off continues since little power is needed to hold 13.?v at the battery, now this is with no load and varying light conditions. By definition I consider it 100% when it went to float.  |
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Post by tattoo on Mar 3, 2018 6:38:12 GMT -8
Cool thank's for that Bird. I understand it a little better.... But for 99% of the people out there it's useless.... LOL No need trying to get people to understand it... Thanks
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papa
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Post by papa on Mar 3, 2018 10:43:21 GMT -8
Yes, I agree with tattoo. The data report is cool. Really appreciate your efforts explaining. I Thank both of you for the dialog on this topic.
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Post by tattoo on Mar 3, 2018 16:19:14 GMT -8
Yes, I agree with tattoo. The data report is cool. Really appreciate your efforts explaining. I Thank both of you for the dialog on this topic. Anytime,,,, Hope you are enjoying your solar system as much as I am... |
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