I would like to change from AGM to Lithium batteries but because many require 30 mins or less absorption im not sure if its going to be Possible without changing my Charge Controller which i dont want to do, its the Older Blue Solar metal unit with a screen and 4 buttons for setup etc the front .
The MPPT i have now uses the voltage in the early hours to deterring the absorption duration , and i am always in the 24.6-24.8 range so its a 5 hour duration which is also what Trojan batteries state , unfortunately the method is far from perfect as a motor cutting in during the hours before charging drops my battery's voltage to just under the threshold so i often have to manually end absorption rather than let it run for 10 hours which is the duration for below 24.4 volts . The units are not programmed to take into account the drop in voltage which is a second or two then returns to normal
End amps also fail to do what is necessary and go to float at 2 amps , if theres any load then the current for that wil take the figure above 2 amps , with no power my end amps are 1.9 amps and often reached when the inverter is turned off and with no load it will immediately go into Float but turned back on with even a small 20 watt bulb the end amps coming in are taken above 2 amps and holds the charge in Absorption . Im surprised Victron has not addressed either of these issues .
My concern is that these anomalies will damage Lithium batteries as i dont know how resilient and forgiving they are , thermal runaway is a concern .
