SternWake
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- Nov 30, 2013
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Waking up to 12.3 to 12.4 volts is expected with the loads you list Fred. Especially with a fridge fighting 118f ambient temperatures.
Unless you have more than about 230AH of total house battery capacity.
12.3 to 12.4v is actually pretty good. If you were to remove all loads from the battery, in an hour or 2 it could very well rebound to significantly higher.
When the batteries are low mid to late morning, I really try to not run any extra loads until it hits absorption voltage. i wantmost all of the solar going into filling the battery at a faster rate. One might get to float voltage later in the day, and feel the false sense of battery charge completion but in my years of observations, the earlier in the day the battery rises to absorption voltage, the happier it is. That last 3 to 5% can take 2 hours or more, and day after day of cycling, that last 3 to 5% really impacts the battery when it is not achieved
It is very possible and likely even, that your solar controller is not actually fully charging the batteries. Just because the green light flashes and it goes into float mode, does not mean the battery was actually full. It only means that absorption voltage was held as long as it was programmed to do so.
As the Ideal absorption voltage and duration are a moving target, and are slightly to largely different on each and every battery, and drift with age. The Ideal absorption voltage and duration is also affected by the level of discharge, as well as the number accumulated cycles since the last true 100% recharge as well as battery temperature, and the proximity of the nearest locust.
Out of the box, charge controller parameters could be way out of Whack with reality as to what the battery needs in a certain service.
If you have flooded batteries, and can control absorption voltage and duration, some trial and error with a Hydrometer will let you know how well the charge controller is doing in your usage Most everybody who has supreme confidence in their solar controller, would be disappointed at the Specific gravity readings when it first drops to float mode.
If you have AGM, then basically they need to be held at absorption voltage until amps required to hold absorption voltage taper to 0.5% of total battery capacity. 0.5 amps per 100AH of battery capacity, and even then it is no guarantee the battery is at maximum energy density.
Because,
AGM's also occasionally need higher recharge rates to keep happy. Low and slow solar combined with incomplete charging, tickles AGM batteries in to an early grave, with some being worse than others in this regard.
So Any solar is better than no solar, but just any solar wattage and standard controller charge algorithm hooked to any battery does not mean the battery is as happy as it could be. It could be close, and good enough, or it could be after a week or two of cycling to 50%, the cycler notices something is 'not right'
---
Ir thermometers read inaccurately when aimed at reflective surfaces. Like I can pull out a beercan at 33.f. Tooth hurting cold, but the IR thermometer would read 55F. Cant drink cheap american swill at 55f. The IR thermometer is wrong.
My friends ARB chest style fridge, its thermometer was very inaccurate. I had to set it to 26 to keep it in the low 30's on average. My IR thermometer read 5-10 degrees hotter inside than the display showed, and certain surfaces within were obviously a false reading showing practically ambient temps.
Jim, sounds like you have an absorption fridge and it is throwing a tantrum at the ambient temps you are dealing with. Make sure the unit is level and the cooling unit can breathe.
Unless you have more than about 230AH of total house battery capacity.
12.3 to 12.4v is actually pretty good. If you were to remove all loads from the battery, in an hour or 2 it could very well rebound to significantly higher.
When the batteries are low mid to late morning, I really try to not run any extra loads until it hits absorption voltage. i wantmost all of the solar going into filling the battery at a faster rate. One might get to float voltage later in the day, and feel the false sense of battery charge completion but in my years of observations, the earlier in the day the battery rises to absorption voltage, the happier it is. That last 3 to 5% can take 2 hours or more, and day after day of cycling, that last 3 to 5% really impacts the battery when it is not achieved
It is very possible and likely even, that your solar controller is not actually fully charging the batteries. Just because the green light flashes and it goes into float mode, does not mean the battery was actually full. It only means that absorption voltage was held as long as it was programmed to do so.
As the Ideal absorption voltage and duration are a moving target, and are slightly to largely different on each and every battery, and drift with age. The Ideal absorption voltage and duration is also affected by the level of discharge, as well as the number accumulated cycles since the last true 100% recharge as well as battery temperature, and the proximity of the nearest locust.
Out of the box, charge controller parameters could be way out of Whack with reality as to what the battery needs in a certain service.
If you have flooded batteries, and can control absorption voltage and duration, some trial and error with a Hydrometer will let you know how well the charge controller is doing in your usage Most everybody who has supreme confidence in their solar controller, would be disappointed at the Specific gravity readings when it first drops to float mode.
If you have AGM, then basically they need to be held at absorption voltage until amps required to hold absorption voltage taper to 0.5% of total battery capacity. 0.5 amps per 100AH of battery capacity, and even then it is no guarantee the battery is at maximum energy density.
Because,
AGM's also occasionally need higher recharge rates to keep happy. Low and slow solar combined with incomplete charging, tickles AGM batteries in to an early grave, with some being worse than others in this regard.
So Any solar is better than no solar, but just any solar wattage and standard controller charge algorithm hooked to any battery does not mean the battery is as happy as it could be. It could be close, and good enough, or it could be after a week or two of cycling to 50%, the cycler notices something is 'not right'
---
Ir thermometers read inaccurately when aimed at reflective surfaces. Like I can pull out a beercan at 33.f. Tooth hurting cold, but the IR thermometer would read 55F. Cant drink cheap american swill at 55f. The IR thermometer is wrong.
My friends ARB chest style fridge, its thermometer was very inaccurate. I had to set it to 26 to keep it in the low 30's on average. My IR thermometer read 5-10 degrees hotter inside than the display showed, and certain surfaces within were obviously a false reading showing practically ambient temps.
Jim, sounds like you have an absorption fridge and it is throwing a tantrum at the ambient temps you are dealing with. Make sure the unit is level and the cooling unit can breathe.
