We are camped at Cosy Corner WA just outside Albany,we have 480 watts on the roof 3x120ah batteries 40 amp dcdc solar regulater,first day sunny blue sky ,the most voltage 14.4 8 amps ,we have had very little sun for the last few days.Since then 13.7volts and about 5 amps.Today blowing a gale,overcast 14.7volts forgot to check amps,but why so high voltage?
To me it depends how much you are drawing off the batteries, That voltage indicates they are on float. Mine can get that high also while charging but night time it will drop down to high 12's which is fine, never had mine under 12.5. Are they setup in series or parallel?
To the contrary, I would suggest at 14.7volt the battery charging device is at the absorption stage, with a lower float voltage (see chart below).
Difficult to provide further comment without detail of your equipment.
Is the 14.7volt you nominate a recorded "maximum voltage" or a sustained voltage level? What device is reading/displaying this voltage level.
The below is from a Victron MPPT 100/50 solar charger manual and provides various voltages for different stages and covers a range of battery chemistries.
They are connected in parallel, i have victron bmv 702 monitoring the batteries,most days the reading are 13.5 during the day as night falls drops down to 12.7 in the morning 12.4/12.5 and the worse 91% soc.But normally 100% before 10am bit slower today .It just confused me 14.7 no sun and cloud
You may have just viewed the 14.7 volt at the absorption stage today, prior to the controller switching to float stage.
The BMV has history available. Maybe maximum voltage is recorder and reset this history daily. Or if you have Victron MPPT controller and MPPT display or bluetooth you would have daily history available which includes max/min volts, absorption time etc.
Do you have a multimeter available to confirm the reading of the reading of the BMV702?
No need to be confused - your regulator's doing the right thing, despite the cloudy weather!
The Redarc BCDC manual says 14.6 is the maximum voltage (for sealed batteries) so you're almost spot-on - as others have said, this is the absorption phase which slowly brings the battery up to 100%. The 0.1V diff could be either a tiny bit of voltage over the cable while it's charging or maybe just the meter (they're all +/- 1 digit accuracy).
As the others have said, the 13.something Volts will be when the battery is in float - so it's full and doesn't need any more from the solar. And the morning voltage of 12.4V just indicates you've used some power overnight, and given your nice 480W of solar that'll be up in no time.
So the short version is All Good!
-- Edited by AJC on Thursday 16th of March 2017 01:39:32 PM
Thanks for that AJC it is good to know that things are working well, this morning 8-00 am 100% that is with a 39 litre engel and a 210 litre frigio in side both running off the solar
