I have an Easysolar 48/5000/70-100 with CGX and seperate BMV 702.
I notice that there is an installed battery temperature sensor to the EasySolar, and I assume that is part of the charger (it is not the optional BMV one). I would like to know if it is possible to configure the system so that that temperature information feeds the BMV state-of-charge calculation?
Hi @Gavin Andrews,
not sure I understand your question correct. But the temperature information, be it from the EasySolar or the BMV, has nothing to do with SoC calculation.
SoC highly depends on measuring charge and discharge energy in and out of the batteries.
My layman's understanding is that battery capacity is affected by temperature. SoC is expressed as a percentage of capacity.
Yes, this is true and I must correct myself after reading the manual for the BMV (I really never used the option Setting #68 to control capacity). Sorry for the confusion.
I've never used the temp sensor.
For the BMV you need to change setting #68 in the menu and set percentage the capacity will drop with one degree celsius. Around 1%/°C for Lead Acid or 0.5%/°C for LiFePO4 (as per the manual, but might be different for your batteries). But that requires the temperature sensor (the one for the BMV) to be properly installed. AFAIK the temp sensor for the EasySolar is a different type and can't be used with the BMV.
Usually the standard rating is set for temperatures at 25°C. At around minus 30°C one may loose up to 50% of battery capacity. At about 0°C it's roughly 20% loss.
But in terms of SoC calculation usually the temperature is neglected.
Thanks Stefanie.
Seems logical that one temperature sensor in the system could be used for multiple functions. But apparently that's not the case.............(yet?)
