[RE-wrenches] Controller Adjustment?

[Larry Crutcher, Starlight Solar Power Systems]

Jeremy,

This is often the scenario for many of my customers in Mexico: owners are absent for 5-8 months. Batteries will last longer if charged slowly at lower voltages. But, getting a full charge daily with a PV solar resource sometimes takes longer time than there is sunlight available. For this reason, I use an aggressive charge regime of higher voltages and longer absorption time on batteries that are daily cycled. However, higher voltage and long charge will shorten the life of batteries that are not being cycled or are shallow cycled. 

My advice is to reprogram the controller for 2.36 Vpc and absorb time of 1 hour. This voltage will prevent much water loss. If the bank is healthy, they can last for many months with these settings. Be sure to check and equalize if more than 0.015 SG cell to cell difference is detected over that time. Also equalize well before putting back in cycle use next time.

Larry


On Oct 28, 2013, at 3:37 PM, "All Solar, Inc." <allsolar at scswifi.net> wrote:

Hello 
Is there any reason to adjust a charge controllers bulk or other settings if there will be very minimal loads on the battery bank for 5-6 months ? Just had a client ask me that about his new MN classic. 

Thank you 
Jeremy Rodriguez
All Solar