I am at the point of wiring my system. I would like to have a battery monitor and was eyeballing the Trimetric 2025 but would much rather have the upcoming Midnite one. Any thoughts on when it will be released before I waster $160 on the Trimetric?
Additionally, I am using Deltec 500a 50mv shunts. Will those work with this new monitor?
Thanks!
would have to ask midnite about that. don't think it will be out as early as you may want it to be.
The current sense module is done hardware wise. boB has started the code to make the classic read it and do things with the amperage like EA etc. After that he will start work on the actual battery meter portion of the code. I am not sure I can put a time line on it but I would say a month or two?
boB??
No worries. I picked up a Trimetric for now. That EA feature will sure be nice but it looks like I will lose my Aux 2 to the BM if I am reading all of the threads right.
Quote from: Tons001 on September 04, 2013, 09:17:52 AM
No worries. I picked up a Trimetric for now. That EA feature will sure be nice but it looks like I will lose my Aux 2 to the BM if I am reading all of the threads right.
Not sure what you mean ? Are you using now or planning on using Aux 2 for something other than the BM ?
The Whizbang Junior shunt monitor is basically done and we are actually shipping some next week.
The (early) Classic code probably has another week to go but the first customer is going to update
their Classics since they are in Australia and want the hardware there ASAP.
boB
I am currently using Aux 1 for Vent Fan Hi and Aux 2 for Nite Light. If the shunt monitor needs to hook up to an Aux, I guess I could put both relays on the Nite Light aux and adjust the normally opened/closed on the relays for the outdoor lighting and battery box fan.
Quote from: boB on September 08, 2013, 01:10:20 AM
The Whizbang Junior shunt monitor is basically done and we are actually shipping some next week.
The (early) Classic code probably has another week to go but the first customer is going to update
their Classics since they are in Australia and want the hardware there ASAP.
boB
Hey boB,
That is great news ... getting closer than I would have guessed. Great work and news! Thanks, Vic
great when will it be available from retailers?
Quote from: mahendra on September 10, 2013, 05:50:58 PM
great when will it be available from retailers?
Not sure yet. We've shipped some already. Waiting for the
little plastic covers that will hopefully be in next week.
boB
ok thanks boB
Are the specs or a preview of this device available on the website yet? I was wondering about wiring configuration with large capacity DC bus with multiple parallel feeds to the bus from the battery, and how it will work.
Thanks!
--
Chris
Well, this little Whizbang Junior just connects to the 2 terminals on your typical
Deltec shunt and a single wire (22 gauge ?) runs to the Classic's Aux 2 terminal.
So, however that shunt is wired.
As far as specs, I don't have a final number yet but we are seeing less than < 0.5 percent worse
case delta from reading the shunts by Fluke meter. The Deltecs are spec'd at +- 0.25 %
boB
Quote from: boB on September 16, 2013, 09:42:17 PM
Well, this little Whizbang Junior just connects to the 2 terminals on your typical
Deltec shunt and a single wire (22 gauge ?) runs to the Classic's Aux 2 terminal.
OK, so you basically have to buy whatever shunt is appropriate for your system, then connect the Whizbang Junior to it like any other ammeter would connect.
What mV shunt does it require? I need to start looking for the biggest 500 amp shunt I can find. The shunts I have seen that are "500 amp" don't have even close to big enough studs on them to connect the cables to from our bus.
--
Chris
We have had a couple overcast days. My Trimetric is showing -80 cumulative amp hours total out of the bank. It is sunny today and I thought the Classic would have stayed in bulk longer than it did. I adjusted for a longer absorb in hopes to replace as many amps as possible but I doubt I will make it. My batteries ask for a 2 hour absorb which I have extended to 5 hours and set my end amps to 4. If I kept it at a 2 hour absorb, I would end up in float with a rather large amp hour deficit still in my back ... at least according to the Trimetric.
So my question is two part. First ... I am assuming the Whizbang Jr is the answer to fixing this because the Classic would then know exactly how much to replace? Second ... is there anything in the immediate I can do dump more current into the battery bank or was increasing the absorb time my best bet?
Or I guess a third question is am I complete idiot? :o
Tons ..,
Battery monitors DO need to be calibrated to be accurate. The number of AH needed to be returned to the batteries depend upon the rate at which the AH were removed, the charging efficiency of the batteries (AGMs are fairly efficient), temperature effects and more.
With AGMs, it is not possible to measure the state of charge by sampling the electrolyte, so End Amps, and resting voltage are two methods of knowing fairly well the SOC of the bank.
The WhizBang Jr. will be able to measure the actual charge current going into the battery bank. You will need to determine the correct setting for EA so the WB can terminate the Absorption stage of charge.
The battery manufacturer may well specify what this EA or Finishing Charge rate is for your batteries. Removing all chargers and all loads from the batteries after you believe that they are fully charged, and letting the bank "Rest" for a number of hours will allow you to measure the Rested voltage which can be a very good indication of the SOC, and allow you to zero in on the correct EA setting in the Classic.
Just a drive-by post, later, Vic
Thanks Vic.
Quote from: Tons001 on September 21, 2013, 02:38:57 PM
We have had a couple overcast days. My Trimetric is showing -80 cumulative amp hours total out of the bank. It is sunny today and I thought the Classic would have stayed in bulk longer than it did. I adjusted for a longer absorb in hopes to replace as many amps as possible but I doubt I will make it. My batteries ask for a 2 hour absorb which I have extended to 5 hours and set my end amps to 4. If I kept it at a 2 hour absorb, I would end up in float with a rather large amp hour deficit still in my back ... at least according to the Trimetric.
So my question is two part. First ... I am assuming the Whizbang Jr is the answer to fixing this because the Classic would then know exactly how much to replace? Second ... is there anything in the immediate I can do dump more current into the battery bank or was increasing the absorb time my best bet?
Or I guess a third question is am I complete idiot? :o
Question on the Trimetric's accumulation of NET amp-hours... How often does that reset ?
I would think that to keep a battery charged, that the amp-hours into the battery would just keep on
going up and up and up and so would have to be reset at least once in a while so that you're not
constantly looking at amp-hours gone by from a week or more ago.
It has been a while since I've used a Trimetric.
boB
boB;
How will this work with dual Classics, E-Panels and stacked Inverters like I have?
Both E-Panels have a shunt in the DC bus. Mine has a shunt in each negative line so it only sees the current in its' respective charging / inverter system.
Just something I wondered about.
Tom
Quote from: boB on September 21, 2013, 03:40:46 PM
Question on the Trimetric's accumulation of NET amp-hours... How often does that reset ?
I would think that to keep a battery charged, that the amp-hours into the battery would just keep on
going up and up and up and so would have to be reset at least once in a while so that you're not
constantly looking at amp-hours gone by from a week or more ago.
It has been a while since I've used a Trimetric.
boB
[/quote]
I have the trimetric set to reset when the voltage is above 28.3 for more than an hour AND the end amps is below 6. The classic is currently set to absorb at 28.6 for four hours with an end amp of 4. I am accounting for a known 2amp constant load on the battery. Even though the trimetric is set to auto reset when the charged values have been met, it never resets the cumulative amp hours but it will reset the days from charged to 0.
With no way to measure SG, I waited until the Classic hit and stayed in float for two days in a row then manual reset the Trimetric's net amp hours to zero. I also disconnected loads, waited a few hours and matched up the resting voltage of the bank and classic measured with a multimeter. The AH of my bank is programmed into the Trimetric.
My question is less about the Trimetric and more about whether the Whizbang Jr will have more active control of charging the bank. I know the Trimetric is just a monitoring tool to help gauge SOC but with AGM batteries it is really the only tool besides resting voltage. If I ever redo this, I'd probably go with FLA batteries to avoid the guessing game.
Quote from: Tons001 on September 21, 2013, 05:01:38 PM
My question is less about the Trimetric and more about whether the Whizbang Jr will have more active control of charging the bank.
Tons ..,
As I read it, at first release the WhizBang Jr. WILL have the ability to terminate Absorption from the Classic, based on an EA setting. This EA setting will be the ACTUAL charge current into the battery bank, not just based on the Classic's output current. So, the WB Jr. will have a control function based on the current INTO the battery bank.
It appears that the WB Jr. is just over the horizon, IMHO, Reality may differ. Vic
The diff betw the trimetric and the classic is that the trimetric knows the true net balance into or out of the battery. The trimetric however doesnt know what the actual load is, or what the charge is, cant dinstinguish them apart. OTOH the classic without WB Jr knows what the output is, but also, not what the loads are, or what the charge current is. So neither solution alone works. Using both combined and a bit of maths does however give you the full picture. The other way around that is with the pentametric and multiple shunts.
The classic with WB Jr, will know the charge rate from its internal shunt, plus the net current into or out of the battery, via the WB jr, and hence by subtraction, it will also know the true charge rate, and the loads. Bring it on baby.
Okay ... so after thinking about it for a week and researching online which this forum & NAWS is great for, I believe my issue is not enough panel for the size of my battery bank. I simply do not think I was dumping enough current into the bank. Luckily I have not yet bought inverter so rewiring from 24v to 12v was a 30 minute job. According to the Midnite sizing calculator, I should now be dumping 37.5 amps into the 12v/305ah bank vs. the 18 amps that was going into the previous 24v/305ah bank. Now to see how warm the Classic gets with the same size array but 12v bank......
Am I thinking about this correctly? I am relatively sure I was deficit charging. Luckily it was only for a couple weeks.
I want to eventually get back to the 24v system but I will have to add more panel.
Quote from: Tons001 on September 22, 2013, 04:07:21 PM
I believe my issue is not enough panel for the size of my battery bank. I simply do not think I was dumping enough current into the bank. Luckily I have not yet bought inverter so rewiring from 24v to 12v was a 30 minute job....I am relatively sure I was deficit charging.
How did you arrive at that? If by 'not enough panel', you mean not enough volts then reducing bank to 12 volts will help, but reconfiguring array would be better. However, if you mean not enough amps, what is the Wp of the PV compared to Ah of bank? Are you sure you arent inventing problems? What was your orig OP issue again? Reducing batt voltage doesnt sound like a step in the right direction.
Currently have 540wp from the array and it was going to a bank of four 6v/305ah batteries. I live in a suburb of Chicago so my lot is only 1/4 acre and I can only fit so many panels. The max current I ever saw going to the batteries was 18a and when you subtract out the constant 2a load ... the batteries were getting 16a peak or 5.5% charge rate. I took two of the 6v batteries out which according to the Midnite string calculator will give me a peak of 37.5a minus the now 3a constant load should be 34 or so amps going to 305ah bank or 11% charge rate.
Or is my thinking wrong?
Everyday I watched the cumulative ah on the Trimetric get further and further away from 0 even when the Classic reached float. My only conclusion was that I am dumping enough current into my battery bank during the bulk stage.
I also currently don't have an inverter/charger so I was using a Mastervolt converter to go from 24v->12v to power the 12v equipment I currently have.
I also oversized my wiring when I did the install so 12v doesn't concern me at the moment. Array to the Classic via 4awg. Classic to bank via 4awg. Batteries currently using 4/0awg.
See attached.
Edited mistakes:
Your panels: http://www.enfsolar.com/pv/panel-datasheet/Monocrystalline/90
Vp=18V, Ip=5.4A That would give you:
Ip Vp inStr nStr Vp Ip Wp
------------------------------------------------
5.4 18 6 1 108 5.4 583
5.4 18 2 3 36 16.2 583
5.4 18 3 2 54 10.8 583
5.4 18 1 6 18 32.4 583
54V is about right for 24v. You need about 2 times nominal. Available charge current is 583W/27v=21 amps, into 300 Ah is a tad low, but for agms will probably work. Your basic problem is not enough pv. Youre also barely giving the classic anything to do, so you had better turn it off at night, the tare losses will bite hard.
You are dead on. I was uploading the pdfs when you were responding. The array was always in two parallel strings of three. I can't currently add panel so dropping the system voltage since I have yet to purchase an inverter seemed like the best option.
And should have typed "battery voltage" not "System voltage".
Its not the battery voltage you need to reduce its the battery Wh.
You might have imcreased the controller output amps, but you just split that in half again to charge the cells in parellel, yeah?
I did reduce it. I completely removed two of the batteries. I did not rewire them in series/parallel to make a 12v/610ah battery bank. I just have two 6v/305ah batteries in series. It was my "oh crap" moment about 2 hours ago when it dawned on me that I don't have enough panel to properly charge my battery bank.
Maybe at some point I will figure out a way to add more panels so I can either go back to a 24v/305ah bank or wire them in series/parallel for 12v/610ah bank. Obviously neither one may be possible on how long the two now unused batteries sit. I will throw the two extras on a maintenance charger for now.
Ok sounds like a plan.
Quote from: Tons001 on September 22, 2013, 05:31:16 PM
I did reduce it. I completely removed two of the batteries. I did not rewire them in series/parallel to make a 12v/610ah battery bank. I just have two 6v/305ah batteries in series. It was my "oh crap" moment about 2 hours ago when it dawned on me that I don't have enough panel to properly charge my battery bank.
Maybe at some point I will figure out a way to add more panels so I can either go back to a 24v/305ah bank or wire them in series/parallel for 12v/610ah bank. Obviously neither one may be possible on how long the two now unused batteries sit. I will throw the two extras on a maintenance charger for now.
Lash out on a couple of decent battery isolator switches. (Can get decent 500A units for as little as $10-$15).
Put two 6V batteries in series, with an isolator.
Put the other two 6V batteries in series, with the other isolator.
Connect both to the charge controller.
Assuming your loads are light enough to get away with it, you can isolate one bank and hit the other hard.
When it reaches float, bring the other bank on and isolate the first. When the second bank gets to float, bring them both online and let the controller "float" them together when it needs far less current.
Just thinkin'...
I like what you're thinking! Thanks.
Quote from: Tons001 on September 22, 2013, 05:31:16 PM
I did reduce it. I completely removed two of the batteries. I did not rewire them in series/parallel to make a 12v/610ah battery bank. I just have two 6v/305ah batteries in series. It was my "oh crap" moment about 2 hours ago when it dawned on me that I don't have enough panel to properly charge my battery bank.
Maybe at some point I will figure out a way to add more panels so I can either go back to a 24v/305ah bank or wire them in series/parallel for 12v/610ah bank. Obviously neither one may be possible on how long the two now unused batteries sit. I will throw the two extras on a maintenance charger for now.
Tons
Looks like this is a similar thread to what was going on in the WB Jr Q&A and probably a more appropriate place is here. It sounds like you may have add another 2 panels to help out. But living in Chicago probably doesn't help especially this time of year with less sunlight. ;)
I've plugged what I believe is your current panel data into a spread sheet I've used that someone else created. What I like about it is besides the STC ratings it shows a couple of other conditions based on temp and amount of sunlight that has to be taken into consideration for actual panel watts out. As you have noted most battery manufactures spec a particular minimum amps for charging based on the AH size of the batteries. Depending on how discharged the batteries get before getting charged again and whether is was a constant or hard discharge have an effect. If you have Excel you should be able to play with the numbers to see the various output you can expect from you system. Hopefully you are able to keep your batteries charged using your auxiliary charger as the SunExtenders are a good set of batteries. :)
Check out the Magnum Energy ME-BMK battery monitor kit. It comes with a 500A shunt and supports Enet monitoring. Very nice! Very happy with mine in DIY 3000W off-grid system with Classic 150. I have an extra 500A new shunt for sale that I do not need.