I have a new set 2 months old, 4 x AGM leisure batteries through 2x MPPT 100/50.
Throughout the day the voltage sits in float at 13.6. When the PVs turn off it drops straight to 12.2-12.4 and then overnight when nothing is in drops to 11.9 before the PVs turn on in the morning.
Are these readings Normal or is there a problem? What reading should I be getting? It’s a if the batteries are not being charged.
I have the same issue. MPPT 75/15, 104Wh LifePO4. With no load for the last 3 days, fully charged battery during daytime.
The moment the panel voltage drops below 19V (battery voltage +5V I guess), the battery starts draining from 13.8 to 13.3 over 1-2 hours. I have not yet measured the actual current draw in this period.
It then stops draining and keeps the voltage at 13.3 until sunrise. During this time the current draw measured on the battery cable is 30mA, which seems to be normal idle draw for the controller.
I have full trend history to show.
Hi @Darren Maddox, yes your battery voltages do appear to be rather low. Your MPPT charges should be going through a full cycle of bulk, absorption and float each day. It would help to know how much your batteries are being discharged each night and the size of your solar panels. A screenshot from each of your your MPPTs in the morning as well as the battery settings and history would be helpful. Configuring the MPPTs to use a VE.Smart networking will also be helpful to synchronise the charge cycle.
It would also help to see the battery settings in both MPPTs
Hi 1 of the MPPT is showing battery voltage in the morning at 13.6f float but i dont understand why it was 11.9 at moment ago and if i turn the PVS off it goes back to 11.9 like the other one is showing now
Each night they go below 12v as you can see below
If you have intermittent heavy loads, this will cause the voltage to drop temporarily.
It would be really interesting to see the graphs of battery voltage and current for the last couple of days. Assuming your copy of victron connect is at the latest version, use the trend tab and minus button.
Hi here it is. You can see the battery dripping quite hard and fast before recovering but aren’t using anything during those period 
Under zero load, a fully charged AGM in good condition will settle at about 12.6V overnight.
It would help a lot to have the current line on this graph. Gives a good indication of how the battery is accepting charge. Although the summaries show little charge/power.
If possible check current with a clamp meter when the MPPT is off.
Also check wiring for loose connections. Check manufacture date on the batteries, if they were in storage too long, they could have been damaged before they were sold to you.
@Darren Maddox a couple of things to possibly check are faulty wiring or a fuse blown or one of your batteries is faulty.
To check for cabling measure the battery voltage at the batteries and compare this to the mppt output.
Are your batteries individually fused ? If you are using the MRBF fuses these might be blown and you are not aware of it.
Also check your batteries are securely connected and try testing the system with one battery at a time - to test them properly you will need to put them under load.
these are the settings for both
