|Current and Voltage over time whilst driving|
I think I would expect a battery to be able to take more than 16A charge rate. The general recommended rate for charging a lead acid battery is 20% of its Ah rating. ie. for a 115Ah battery, it should ideally be charged at 23A. So I would expect the battery to be able to take more.
I did notice that my Sterling B2B charger has been on the 'Gel' setting all the time I've had these batteries (2.5 years). The charger actually has a 'Sealed Lead Acid' setting, which is more appropriate. According to the manual the Gel setting has a slightly higher float voltage, but the main difference is it's bulk stage duration says '12-24 hours' versus '1-12 hours' for the SLA setting.
So I'm now wondering if my batteries have been being undercharged all this time. Thinking about the general pattern of charge on my batteries they are either charged by the Sterling B2B when driving or by the solar panel when stationary. I've long suspected that the Sterling gets confused by the solar panel. When we start driving, the Sterling B2B charger measures the voltage on the battery bank and from there works out how long the bulk charge stage should be. Since the solar panel is always on, the batteries read a higher voltage then they really are. So I think the Sterling has been running the bulk cycle too short. This combined with being on the Gel setting maybe means they have never reached the end of the bulk stage properly.