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#1
The "Classic" charge controller / Charge terminating based on SO...
Last post by Gordon - Today at 12:59:20 PMHi Folks,
I have a question pertaining to the Classic 150 being used in combination with the WBJr. I recently installed a WBJr. in my system since I wanted it to be monitoring actual battery current to determine when to end the daily charge cycle. Until now I had parameters set for ending amps that included a little "buffer" in the event that I had a load in the house, like the freezer, and I made sure not to have any large draws occur towards the end of the charge cycle. This was working fine, but I didn't want to have to think about it any more so I installed the WBJr and set the end amps to 2%.
What I saw today was interesting. I noticed the end of the charge cycle was coming, but it was not up to absorb voltage yet and it was already indicating a 97% SOC. I looked back a couple of minutes later and it was already in float. BTW, the batteries are LFP and I have charge parameters set that have been working very well. The only change I made when adding the WBJr. was the end amps. It doesn't appear that the charge cycle completed based on the charge parameters that were set, i.e., absorb voltage, absorb time, and end amps, but rather that it terminated based in its internal calculation of SOC. What I mean is that I would have expected it to go longer to meet the parameters and it doesn't seem to have done this.
I will be able to watch it very carefully tomorrow when the charge cycle nears the end, but I am wondering if anyone may know if it is now ending the charge based on its calculated SOC instead of the charge parameters? And if so, how can I change that to get back to the charge cycle ending based on meeting the charge parameters?
I did update the end amps to be based on "shunt" instead of "classic" according to the instructions and also set the total battery capacity (450 AH) and efficiency (98%) in the WBJr. menu.
Thanks,
Gordon
I have a question pertaining to the Classic 150 being used in combination with the WBJr. I recently installed a WBJr. in my system since I wanted it to be monitoring actual battery current to determine when to end the daily charge cycle. Until now I had parameters set for ending amps that included a little "buffer" in the event that I had a load in the house, like the freezer, and I made sure not to have any large draws occur towards the end of the charge cycle. This was working fine, but I didn't want to have to think about it any more so I installed the WBJr and set the end amps to 2%.
What I saw today was interesting. I noticed the end of the charge cycle was coming, but it was not up to absorb voltage yet and it was already indicating a 97% SOC. I looked back a couple of minutes later and it was already in float. BTW, the batteries are LFP and I have charge parameters set that have been working very well. The only change I made when adding the WBJr. was the end amps. It doesn't appear that the charge cycle completed based on the charge parameters that were set, i.e., absorb voltage, absorb time, and end amps, but rather that it terminated based in its internal calculation of SOC. What I mean is that I would have expected it to go longer to meet the parameters and it doesn't seem to have done this.
I will be able to watch it very carefully tomorrow when the charge cycle nears the end, but I am wondering if anyone may know if it is now ending the charge based on its calculated SOC instead of the charge parameters? And if so, how can I change that to get back to the charge cycle ending based on meeting the charge parameters?
I did update the end amps to be based on "shunt" instead of "classic" according to the instructions and also set the total battery capacity (450 AH) and efficiency (98%) in the WBJr. menu.
Thanks,
Gordon
#2
New Product Ideas and Discussion / Re: load management
Last post by Barry Fields - May 06, 2024, 07:26:43 PMWhere am I going here is as follows:
An opportunity load would be engaged based on the PWM% (last 10 min avg) indicating that excess PV power is available.
That load would stay engaged during a minimum run timer MRT (say 20min) .
When MRT =0 then if PWM%avg >0% and SOC >90% the load would continue for 5minutes and rechecked.
If the PWM%avg <0% or SOC< 90% the load would disengage.
A delayed restart timer DRST (5min) would prevent premature re-engagement.
The system would recheck PWM%avg and SOC every 5minutes for possible re-engagement.
This approach would work even without an actual PWM load.
My planned DUMP LOAD would be a rewired hot water heater run my primary inverter. shown below.
An opportunity load would be engaged based on the PWM% (last 10 min avg) indicating that excess PV power is available.
That load would stay engaged during a minimum run timer MRT (say 20min) .
When MRT =0 then if PWM%avg >0% and SOC >90% the load would continue for 5minutes and rechecked.
If the PWM%avg <0% or SOC< 90% the load would disengage.
A delayed restart timer DRST (5min) would prevent premature re-engagement.
The system would recheck PWM%avg and SOC every 5minutes for possible re-engagement.
This approach would work even without an actual PWM load.
My planned DUMP LOAD would be a rewired hot water heater run my primary inverter. shown below.
#3
The "Classic" charge controller / Re: Best practice
Last post by Rob Linschoten - May 06, 2024, 03:41:53 PMAnd the correct answer is:
Remember to set the low SOC setting well below any normal usage situation, like 30%.
So it is now 99% SOC off (can't set it to to 100%) and 30% SOC on, with remote Ewelink phone app/WiFi switch override.
On to the next conundrum....
Remember to set the low SOC setting well below any normal usage situation, like 30%.
So it is now 99% SOC off (can't set it to to 100%) and 30% SOC on, with remote Ewelink phone app/WiFi switch override.
On to the next conundrum....
#4
Lead Acid (Sealed and flooded) / Re: Float current degradation
Last post by Barry Fields - May 06, 2024, 01:26:10 PMUnfortunately I had to correct myself. Updated email questions below.
On further thought, I believe that I should rephrase questions 2 & 3.
(1) Assuming a reasonable absorb time, once given a float voltage of 2.35 vpc, the float current should eventually stabilize @ approx 450ma (for a very healthy battery). SOC=100% TRUE?
(2) If the stabilized float current is above 450ma it is an indication that the battery no longer has 100% of it,s original AH capacity. TRUE?
(3) Is it possible to assign approximate numbers to question (2) ? IE 600ma = 95%AH capacity 900ma = 90% AH capacity
(4) In a parallel battery bank, the bank with reduced AH capacity would achieve 100%SOC (with reduced capacity).
?
(5) That battery would contribute less amperage to the total bank discharge currents and probably require more current in the charge cycle. (efficiency degradation)
On further thought, I believe that I should rephrase questions 2 & 3.
(1) Assuming a reasonable absorb time, once given a float voltage of 2.35 vpc, the float current should eventually stabilize @ approx 450ma (for a very healthy battery). SOC=100% TRUE?
(2) If the stabilized float current is above 450ma it is an indication that the battery no longer has 100% of it,s original AH capacity. TRUE?
(3) Is it possible to assign approximate numbers to question (2) ? IE 600ma = 95%AH capacity 900ma = 90% AH capacity
(4) In a parallel battery bank, the bank with reduced AH capacity would achieve 100%SOC (with reduced capacity).
?(5) That battery would contribute less amperage to the total bank discharge currents and probably require more current in the charge cycle. (efficiency degradation)
#5
E Panel's, Disconnect Boxes and Breakers / MNEPV-300 20A used as 2-pole?
Last post by Saggys - May 05, 2024, 07:39:19 PMI am hoping I can use a MNEPV-300 20A breaker as a 125vdc 2 pole PV input breaker. It is polarized and the one side is jumpered + to - with a copper bar jumper.
I am thinking remove the jumper and install the PV in to the breaker and the load side to the AIO PV input.
The breaker polarity should remain correct. The breaker has a copper jumper for a series connection I believe for the 300 volt rating, the two tabs are ganged together.
Will this work? I already have it and it would save me money.
I am thinking remove the jumper and install the PV in to the breaker and the load side to the AIO PV input.
The breaker polarity should remain correct. The breaker has a copper jumper for a series connection I believe for the 300 volt rating, the two tabs are ganged together.
Will this work? I already have it and it would save me money.
#6
New Product Ideas and Discussion / Re: Whiz Bang Senior
Last post by boB - May 05, 2024, 06:50:09 PMThe WB Jr. information, which is basically just amps is available over modbus.
You can force a bulk/absorb or float using modbus.
This is what Follow-Me does. It sends the charge stage that Classic is in.
So the other units change to Float if one of the other Classics goes to Float.
The other units will also go to Bulk/Absorb when another Classic on the modbus goes to Bulk/Absorb if, say, you force a Bulk in the MNGP.
The MNGP is just a "dumb terminal" basically where it reads the requested number or mode or whatever from the Classic and the Classic tells the MNGP the new number.
So, it is all done over the RS-232 modbus and most of the registers are available on our MODBUS document. It should be updated but the WB Jr. stuff is in there too at least as well as force Bulk or Float or EQ.
https://www.midnitesolar.com/pdfs/classic_register_map_Rev-C5-December-8-2013.pdf
boB
You can force a bulk/absorb or float using modbus.
This is what Follow-Me does. It sends the charge stage that Classic is in.
So the other units change to Float if one of the other Classics goes to Float.
The other units will also go to Bulk/Absorb when another Classic on the modbus goes to Bulk/Absorb if, say, you force a Bulk in the MNGP.
The MNGP is just a "dumb terminal" basically where it reads the requested number or mode or whatever from the Classic and the Classic tells the MNGP the new number.
So, it is all done over the RS-232 modbus and most of the registers are available on our MODBUS document. It should be updated but the WB Jr. stuff is in there too at least as well as force Bulk or Float or EQ.
https://www.midnitesolar.com/pdfs/classic_register_map_Rev-C5-December-8-2013.pdf
boB
#7
New Product Ideas and Discussion / Re: load management
Last post by boB - May 05, 2024, 06:42:10 PMAt 50% duty cycle, a 2000W load should be dissipating 1000 watts *IF* the voltage you are applying to that load is at the voltage required to dissipate 2kW in that resistor.
I'd also use a fan. Maybe.
#8
New Product Ideas and Discussion / load management
Last post by Barry Fields - May 05, 2024, 02:39:13 PMIf I had a 2000watt resistive PWM DUMP load, and the average pwm signal (10 minutes) was over 50%, would that not indicate that I have approx 1000watts of available PV power that I should use for and opportunity load?
#9
New Product Ideas and Discussion / Re: Whiz Bang Senior
Last post by Barry Fields - May 05, 2024, 02:05:09 PMJust a couple more.
MNGP allows a forced BULK. I presume that WBjr can force FLOAT. Can ABSORB be forced in the same way?
If true can that be done on the MODBUS?
Are PWM setpoint & width, or PWM% and SOC available over MODBUS?
Can WBjr data be injected over MODBUS?
Sure Barry just get a computer and program it.
As we progress here, I will need some help.
Best regards Barry
MNGP allows a forced BULK. I presume that WBjr can force FLOAT. Can ABSORB be forced in the same way?
If true can that be done on the MODBUS?
Are PWM setpoint & width, or PWM% and SOC available over MODBUS?
Can WBjr data be injected over MODBUS?
Sure Barry just get a computer and program it. As we progress here, I will need some help.
Best regards Barry
#10
New Product Ideas and Discussion / Re: Whiz Bang Senior
Last post by boB - May 05, 2024, 12:16:46 AMYes, Aux 2, the only PWM port is also used for WB Jr so pick one.
Yes, you can hook up the WB Jr. to either one.
When you say MASTER, the only thing that is master about it is the battery temperature sensor reading comes from that Classic.
The default modbus address for each Classic is 10. You can change it up or down. Usually the main Classic (whatever that really means?) stays at ten (10) and the next one is usually 11. Then it is easier to look at the second Classic with the first Classic's MNGP and vice-versa.
There is a special button push combination to tell the Classic's processor that it's modbus address is now what the MNGPs present address is. I can't remember if this particular action also changes the default MNGP address (both saved in their own EEprom) I think that is the case.
Classic and MNGPs communicate back and forth of course but there are only certain things that are done. All the information and settings for a Classic could be transferred over the modbus but it is limited.
What you could also do is take some small single board computer, add modbus or just use TCP/IP Ethernet (much easier I think) and you could write a program to transfer all sorts of data with your own protocols. All the features that we put in and the ones we didn't put in
boB