From what I have read is that you don't want to float them. I fail to understand how floating a battery at say 13V when its terminal voltage is 13.3V is a problem but I have heard that comment several times. Also, that floating them could reduce their life. Maybe, what people refer to is that if you try to float them at a typical lead-acid float which is higher than bulk or absorption then you might be getting above the 14.4 to 14.6V region where you don't want to go.
When you stop charging, say at 13.8V the terminal voltage will drop a bit but I am surprised that it takes another 30-40AH to get it back up to 13.8V. Are you discharging the battery as well as charging it?
When you get the Winston cells do you also plan to buy new solar panels or try to use the current ones?
I was more interested in why the voltage rises so fast to 13.8v when in bulk mode, even though its nowhere near fully charged, and if a larger pack of cells will do the same thing.
So, fast to 13.8V but from where? 13.4V or 13V? At 13.6V you are hitting the region will it will start to climb rapidly BUT the battery should be somewhere around 90-95% SOC. What happens if you leave the battery sit disconnected for several days? Does the terminal voltage keep dropping?
My SBMS is set up to stop charging when the first cell reaches 3.55V (all other cells will be very close to 3.55V as the active balancing only takes place during charge). Mine is set up so that charging starts when the first cell drop below 3.4V (all the other cells will be fairly close to 3.4V). Everything is fully adjustable. Yes, PV is switched completely off.
He builds very good hardware and has been very helpful.
If you are happy manually balancing the batteries then all you need is HVD and LVD. There are people around who say balance them once a year BUT have the above protection.
