Load first or battery first?

Mike Hoxbig

Honorary Master
Joined
Apr 25, 2010
Messages
43,328
How do you guys have your inverters configured to use your PV in the morning?

I've had mine on battery first for about a month and noticed that everything gets sent to charging the battery, and grid powers the load while this is happening.

With load first it would seem more efficient. Batteries take longer to charge but you're not drawing from the grid. This could be a problem on cloudy days.

Has anyone done some long term tests on which is more efficient over the long haul? I'd prefer to set it and leave it, and not have to manually change it depending on weather...
 

Mzezman

Expert Member
Joined
Nov 13, 2021
Messages
2,638
Mine is load first, and yes it does impact battery charge on days like today...yesterday i ended the day on 85% as it was overcast but i didnt use any grid even with some higher loads (geyser)
 

Steijn1

Well-Known Member
Joined
Aug 23, 2015
Messages
240
Same.
Priority is the load.
If my battery is not fully charged by midday then the grid is used to bring them to 100% for the night.
Seems to work perfectly on most days
 

Saba'a

Executive Member
Joined
May 21, 2009
Messages
8,232
Load being essential; non-essential or full load?

Mine is load priority BUT with CT coil issue load seems to be non-essential only.
 

Magnum

Executive Member
Joined
Mar 12, 2013
Messages
6,593
Battery first. All load disabled until solar is sufficient to bring load back online.
 

Snyper564

Honorary Master
Joined
Oct 1, 2008
Messages
15,343
I always do load first then battery - GRID is always my last option. Want to use as little or even better none if possible.

The only time I change this possibly is when there is load shedding then battery is top priority
 

Zerc

Active Member
Joined
Jan 4, 2011
Messages
39
Load first but also setup so that batteries must be at least 40% charged at 10:00 and 75% at 17:00 even if it means charging them from the grid. This is to ensure that I have enough energy so if there is cable theft or other issues I
will be able to continue powering the house through the night.
 

Tacet

Expert Member
Joined
Feb 16, 2010
Messages
2,733
The battery first, load second, idea probably comes from VRLA batteries that really doesn't like to be partially discharged for extended duration (plate sulphation being the risk). With lithium that is less of an issue.
 

Hd7

Well-Known Member
Joined
Oct 10, 2021
Messages
117
Load first for me, usually have my moderate load appliances kick in from the morning (pool pump, washing machine etc) while the production is still ramping up. Then ask my panels to run the geysers during peak pv and send surplus to the batteries. I've never started an evening with less than 90% so pretty happy with it
 
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