Originally Posted by witzgall
Chris from Balmar
here. When you are seeing that 20% very early in the discharge cycle, what does the SG200 show as the State of Health
If you batteries
are compromised, but the SG200 has not yet learned your batteries
and is showing a SoH of 100%, then what you are seeing is plausible. Essentially, your SoH should be lower, and the monitor
recognizes the decreased capacity as the voltage is going much lower than it should for the removed AHs. THis is still better than a typical AH meter, which would simply count down from 100%, damn the actual capacity. Once you get a good SOH, then the SoC should be more linear.
If you do have a bad cell, then the SoC may drop to 0% perhaps 20-30% before the bottom. I have seen this where the SOC is in the 50s, and then boom it is 0%. This is because the voltage and calculated impedance are soo out of range that goes to 0%. Especially if you hit termination voltage way before you should.
Chris this is so embarrassing to admit to, but i feel like i should because it affects the way people may perceive your product.
I posted earlier in this thread i was 100% sure i had the SG-200 wired properly and noted it was reading 100% health
when i pulled my now confirmed bad Trojans. By the time i pulled them it should have learned they were bad or started to degrade some amount at least. My comment would have made it appear it was possibly a defective unit or that it was not working as designed.
I was going through photos of my original installation
when the SG-200 and t-105's were installed and to my extreme embarrassment realized i may have had the shunt hooked up backwards. Its hard to see but in the pic it looks like i can clearly see the cable between the shunt and bus bar says 'BAT' which should be between the battery
and the shunt.
When i removed and re-installed it last weekend, when i removed the trojans, i did manage to actually install it correctly with the short cable coming off the neg battery post going to the shunt 'BATT-' connector. im back at the boat
tonight and have only charged my tiny little 65Ah dual use battery twice and interestingly, the SG-200 is recording 97% SoH, the first time its ever recorded anything other than 100% I know this battery is old and pretty beaten up so may show an even much lower SoH before i pull it and replace it with a Firefly.
So it appears i was in the wrong and wanted to post my clarification so as to not tarnish the SG-200's performance from inaccurate information. Now that it seems to be capable of doing its job it will be interesting to see what info i get.
Thanks for your contributions to these threads. Hopefully i didnt do any damage to the unit and maybe your engineers will sleep a little better tonight.