Its a 2S lifepo4 24v 300ah system (6 100 ah 12v batteries) The solar panels are 5S 12v with many more paralleled into the five in series. In full mid day sun, I only get about 400watts. I run only a big fridge and freezer off of the system 24/7. So typically the batt ah might go down from 300 ah fully charged to 60% in the morining when the panels start generating power. In mid- morning on a sunny day, I check on it and its still about the same. But If I come back to it only an hour later, its showing 99% and its in float mode. And stranger still, its been in float mode over three hours and the bank charging rate is still at 15 amps. This would be .5C, right? The inverter load as shown on Wizbang display is about 1.5 to 4.5 amps only. I thought that once float mode started, the charging amps would drop down to a very low value.
Could you give some more info ?
What brand of batteries are they ? ( so I can look up the manufacturer specs)
What kind of panels do you have ?
What are the Absorb, Absorb time, Float setpoints you have programmed in to your controller ? What kind of controller is it - Classic or Kid ?
The correct terminology for your battery setup would be 2s 3p ( 2 in series and 3 parallel )
Have you put the panel specs into the Classic string calculator ( there is a different calculator for Kid)
https://www.midnitesolar.com/sizingTool/index.phpSome considerations - wiring is important to try and have all wiring resistances be the same . See this
http://www.smartgauge.co.uk/batt_con.htmlIn general lithium will charge at the same voltage for a long time, then quickly rise to absorb setpoint, and go to float . You may not notice the transition from absorb to float depending on your setpoints.
The reason you may see it at 99% in Float is because depending on your settings and load it will have to use a bit of the stored energy in battery before it drops to Float voltage .
You may see it charging in float depending on your settings. And it could be your don't have the Absorb voltage high enough so the batteries continue to charge in Float - really depends on what you have set for them and how you have them wired.
Larry
Recent Posts
