Everyone!
We have had some really crappy cloudy weather here in ohio, and to keep the batteries healthy, I've been using Rosie's internal charger.
My wife is a smoker and went to the garage to light one off, when she came back in and said that the batteries were making lots of noise.
To my surprise, they were sitting at almost 61V and according the display, in absorb mode.
I checked, and I had absorb set on the menu at 58V. When I lowered the value, nothing changed, the batteries were still charging at 61V.
I do NOT have the remote battery sense connected. I checked the batteries with my Fluke and sure enough they were sitting at 61V...
So, what's wrong? Why were the batteries being hit with such high absorb voltage when the setting was clearly much lower.
Good thing she didn't light that smoke up!
mike
What is the temperature in the garage?
it was about 40ish, would temp comp send the charging voltage that high?
A hour ago I tried the charger once again, and the battery voltage immediately went to 60 volts. the battery temp was setting at 5.2ºC (41.3ºF)
Also, is there a bulk voltage setting? I can't find it if there's one to be found
mike
Mine has always done this and nothing has been hurt in the making over the years. In fact I adjust my Absorb voltage 2 or 3 times a year when it starts bouncing from Bulk to Absorb and back to Bulk.
Rosie knows what she is doing it's a lead acid battery, all will be fine.
I think the temperature compensation math goes like this.
25c = 77F
77F - 40F = 37
37 x .005mv/cell x 24 cells = 4.44 v
58 + 4.44 = 62.44v
Depends on what you have your temperature compensation setting at and how cold your batteries are as to what your absorb voltage ( and float) will compensate as you see above. I am assuming you have the temperature sensor on the batteries.
Larry
Thanks, Larry, for your input. I have been thinking this might be the reason why the voltages are so off. However! The classic 150's temp sensor is mounted right next to Rosie's temp sensor, and the classic 150 never reports such high absorb voltages. I wonder why that is.
On the classic's solar status panel on my computer, I see compensate at -0.5ºc.
Why wouldn't the classic 150 do the same thing with the absorb voltage?
Mike
Quote from: qrper on February 17, 2025, 11:28:30 AMThanks, Larry, for your input. I have been thinking this might be the reason why the voltages are so off. However! The classic 150's temp sensor is mounted right next to Rosie's temp sensor, and the classic 150 never reports such high absorb voltages. I wonder why that is.
On the classic's solar status panel on my computer, I see compensate at -0.5ºc.
Why wouldn't the classic 150 do the same thing with the absorb voltage?
Mike
Not sure . Try swapping temperature sensors and see if that changes anything ?
Quote from: qrper on February 14, 2025, 12:03:57 PMit was about 40ish, would temp comp send the charging voltage that high?
A hour ago I tried the charger once again, and the battery voltage immediately went to 60 volts. the battery temp was setting at 5.2ºC (41.3ºF)
Also, is there a bulk voltage setting? I can't find it if there's one to be found
mike
At 5C thats 20C delta,
So 20 degrees x 24 cells times 5 mv is 2.4V so your Absorb voltage should be around 60.6v after temperature correction
Quote from: FNG on February 17, 2025, 02:02:14 PMQuote from: qrper on February 14, 2025, 12:03:57 PMit was about 40ish, would temp comp send the charging voltage that high?
A hour ago I tried the charger once again, and the battery voltage immediately went to 60 volts. the battery temp was setting at 5.2ºC (41.3ºF)
Also, is there a bulk voltage setting? I can't find it if there's one to be found
mike
At 5C thats 20C delta,
So 20 degrees x 24 cells times 5 mv is 2.4V so your Absorb voltage should be around 60.6v after temperature correction
Why isn't the classic 150 doing the same thing? Temp sensor is right next to Rosie's temp sensor and absorb voltage is fine. I can see the temp on the status app, so sensor is working.
Mike
Quote from: qrper on February 17, 2025, 08:48:05 PMQuote from: FNG on February 17, 2025, 02:02:14 PMQuote from: qrper on February 14, 2025, 12:03:57 PMit was about 40ish, would temp comp send the charging voltage that high?
A hour ago I tried the charger once again, and the battery voltage immediately went to 60 volts. the battery temp was setting at 5.2ºC (41.3ºF)
Also, is there a bulk voltage setting? I can't find it if there's one to be found
mike
At 5C thats 20C delta,
So 20 degrees x 24 cells times 5 mv is 2.4V so your Absorb voltage should be around 60.6v after temperature correction
Why isn't the classic 150 doing the same thing? Temp sensor is right next to Rosie's temp sensor and absorb voltage is fine. I can see the temp on the status app, so sensor is working.
Mike
I wonder if the classic has a low upper limit set to it can not adjust correctly or t comp is not set up properly
MAIN MENU--> CHARGE--> LIMITS what is the high voltage limit set to?
MAIN MENU--> CHARGE--> TCOMP what is the mv per degree C set to?
Quote from: FNG on February 18, 2025, 11:29:02 AMQuote from: qrper on February 17, 2025, 08:48:05 PMQuote from: FNG on February 17, 2025, 02:02:14 PMQuote from: qrper on February 14, 2025, 12:03:57 PMit was about 40ish, would temp comp send the charging voltage that high?
A hour ago I tried the charger once again, and the battery voltage immediately went to 60 volts. the battery temp was setting at 5.2ºC (41.3ºF)
Also, is there a bulk voltage setting? I can't find it if there's one to be found
mike
At 5C thats 20C delta,
So 20 degrees x 24 cells times 5 mv is 2.4V so your Absorb voltage should be around 60.6v after temperature correction
Why isn't the classic 150 doing the same thing? Temp sensor is right next to Rosie's temp sensor and absorb voltage is fine. I can see the temp on the status app, so sensor is working.
Mike
I wonder if the classic has a low upper limit set to it can not adjust correctly or t comp is not set up properly
MAIN MENU--> CHARGE--> LIMITS what is the high voltage limit set to?
MAIN MENU--> CHARGE--> TCOMP what is the mv per degree C set to?
I'll have to check the charge limits
the TCOMP is set for -.5mV
mike
I think I may have found a reason why the temp comp isn't working...
Apparently, I never told the whizbang that temp comp should be 1 and not 0, which turns off temp comp.
on limits, I have the upper limit set to 69V.
I'll have to wait a bit to see if the temp comp is working
mike
I'm not proud, and I've been known to raise the white flag at times.
So, I called tech support.
Long story short.
The temp comp temperature offset was set wrong. Instead of 5mV per deg C, the value was .5mV per deg C. Apparently, using the default value wasn't a good idea. And to justify my error, it's hard to see that (.) on the screen.
So, temp comp is now fixed. the classic 150 is now reporting 61.1V in absorb mode.
Since it was my nickel, we poked around some of the setting to get the SOC to work correctly. It will take a few float cycles before I can see if it's working correctly. Today's not going to be a float day.
mike
FYI... Midnite Tech support is the best!
Mike,
Glad support was able to assist and find the issue. I may be biased but I do believe we have one of the best crews when it comes to support