Maximum Compensation Temperature (TS-45 Charge Controller)

Thanks in advance. I am programming a TS-45 Morningstar charge controller for L16 Trojan batteries and there is one parameter that I am trying to understand: Maximum Compensation Temperature (and Minimum). They may just be the battery specification operating temperatures of -20C to +45C but the default TS-45 values are +80C to -40C which is wide so I am trying to make sure I get this right.
The TS-45 help file defines the Maximum Compensation Temperature as "Maximum temperature at which temperature compensation is clamped".
Any insight? Thanks
The TS-45 help file defines the Maximum Compensation Temperature as "Maximum temperature at which temperature compensation is clamped".
Any insight? Thanks
Comments
The controller should increase voltage at lower battery temp, and decrease voltage at higher temps. Having a wide (but finite) range shouldn't be a bad thing. If the batteries are getting to anything like 80°C, you definitely want the controller dialing back voltage. If you never see battery temps less than -20°C, it wouldn't hurt to limit voltage increase there. Some inverters and other loads get picky about voltage when compensated to really cold temps.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
If the bank is even getting as warm as 45°C, you likely have a problem. I would leave it at the default so it keeps reducing voltage at higher temps.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
Maximum Compensation Temperature = All temperatures above +80C, will be treated as if they were +80C
Minimum Compensation Temperature = All temperatures below -40C, will be treated as if they were -40C
If your Charge Controller will be connected to your battery bank AND
your Battery Bank's temperature will be above +45C, or will be below -20C,
then enter the temperature values for your battery.
Changing these limits is not "critical" to normal operation.
My battery bank will never be above +45C / +113F,
and won't be much below -20C / -4F,
so the DEFAULTS work just fine for me.
Many battery banks will get cold in the winter,
but are you really planning on letting the temperature of your battery bank climb above +45C / +113F ?
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
- (-40C+20C nominal)*-0.005 volts per degree C per cell * 6 cells (aka 12 volt battery) + 14.75 volts nominal charging = 16.55 volts charging (@ -40C)
Many AC inverters do not like >15 or 16 volts and will shut down. So while the battery "may be happy", your attached loads may not be in cold climates "unbounded" charging voltages.-Bill