Charge batteries on a night, what should I set my SCC to during the day

[pops106]

I have around 2kw of PV gridtie DIY setup.

8 x 12v 55ah deep cycle AGM VRLA batteries in 4s2p so 48v 110ah.

I have been trying to work out what the best thing to do with the bulk and float volts on the charge controllers, they are super dumb PowMr units with no settings for bulk time.

I charge the batteries using battery chargers on a night during offpeak hours until 1:30am then the inverter kicks back in again so the batteries reach 14.6v ish depending on temps which is around 950w at that point on the charger then it reduces during absorb until around 100w which is when I kick the inverter back in so I believe should be pretty much absorb completed.

So if we imagine the battery has had a proper charge each night and I don't need to change anything above, just for this conversation.

If I set the SCC to be a normal 14.6v bulk and 13.8v float then on decent days of sun the batteries end up bouncing around in and out of bulk and float when a load sags the batteries down or clouds come over etc which I don't think is a great idea, they could spend a good chunk of the day over 14v.

Should I set the SCC bulk to something more like 13.8v and float 13.6v during the day knowing the charge on the night will deal with a proper absorb stage.

 

[DerpsyDoodler]

I have around 2kw of PV gridtie DIY setup.

8 x 12v 55ah deep cycle AGM VRLA batteries in 4s2p so 48v 110ah.

I have been trying to work out what the best thing to do with the bulk and float volts on the charge controllers, they are super dumb PowMr units with no settings for bulk time.

I charge the batteries using battery chargers on a night during offpeak hours until 1:30am then the inverter kicks back in again so the batteries reach 14.6v ish depending on temps which is around 950w at that point on the charger then it reduces during absorb until around 100w which is when I kick the inverter back in so I believe should be pretty much absorb completed.

So if we imagine the battery has had a proper charge each night and I don't need to change anything above, just for this conversation.

If I set the SCC to be a normal 14.6v bulk and 13.8v float then on decent days of sun the batteries end up bouncing around in and out of bulk and float when a load sags the batteries down or clouds come over etc which I don't think is a great idea, they could spend a good chunk of the day over 14v.

Should I set the SCC bulk to something more like 13.8v and float 13.6v during the day knowing the charge on the night will deal with a proper absorb stage.

Ideally, the setting you should be concerned with tuning is "reset to bulk". I don't know what controller you have or what settings it supports, so take what I said with a grain of salt.

 

[pops106]

Ideally, the setting you should be concerned with tuning is "reset to bulk". I don't know what controller you have or what settings it supports, so take what I said with a grain of salt.

I believe this is when the volt drops to say 12.2v for x amount of time then reset to bulk, I don't have any of those types of settings.

It is literally if it drops below float go back into bulk by the looks of it.

 

[DerpsyDoodler]

Then test it. Just set the float voltage a bit lower (or don't). Ideally, you want lead acid to sit at or near full full most of the time, anyway. They like that.