Originally Posted by
mike cunningham
I completed this Test day before yesterday. Very interesting, based upon battery voltage vs SOC, the Zantrex is right on with regard to SOC percentage and appears to be reporting battery condition accurately. What is also good news is my 11 year old AGMs continue to maintain nearly their entire capacity of 110 AH per battery based upon AH consumption/time/battery voltage. I think their longevity is due to their environment (never get outside 65 to 80 degrees F) and the fact that I never cycle below 60 % SOC. During the 16 SHTP I would begin charging in the mid 60% range and go until I had them up to the high 80s%. They maintained a full charge exclusively on SAs when at anchor and in Nawiliwili.
Having said all the above, I did spend $70 on a 18 AH Li battery as an emergency backup. This will be useful ashore as well as afloat.