More Solar for "Us"

[MrWizard]

Ok, I went off.the deep end?
Bought 3 used 37watt uni-solar panels and a blue sky 2000e controller for the hefty price of $400,
They were being listed as 75w panels, they are not

The tested open circuit voltage was 21+, short circuit amps 2.9
I tested each panel multiple times tilted into the sun and laying flat on the ground , got the same readings each way, that was the deciding factor, they appear to put out full power while laying flat, I will try to mount them tomorrow before it gets hot, right now 104°F
I will use the existing wiring until I buy & install the new wire

[MrWizard]

I have not done an in depth analysis
But
I have noticed a higher avg charge voltage
And response is better when the fridge is on or I use the inverter for MW etc..
By setting the higher voltage and the longer boost times plus the return to boost voltage
The controller doesn't wait for the voltage to drop low before returning to boost
This lessens the strain on the batteries

[pianotuna]

Almot,

Don't forget these jars are a special subset of AGM. They behave more like flooded jars--except they don't taper until about 95% state of charge, from what I've been able to glean.

[pianotuna]

MrWizard,

Now that you have had the Grape controller for a while, do you see any change in the solar harvest?

[MrWizard]

Today's cool weather clear sunny skies after yesterday's storm

1069.1 watt hours
76.74 amp hours
277.5 peak watts
18.85 peak amps

Big storm fore cast for tomorrow/Sunday

[Almot]

I don't think he is overcharging. But when system is undersized - seems to be the case - something needs to be sacrificed. Doing 2 stages, boost charge most of the time, is not optimal for batteries, but this is a lesser evil than not getting them to 90-95% at all. AH number for the day does tend to slip lower when Float stage is lingering for more than 3 hours, - though this wouldn't matter with more solar. The batteries would then get over 95% and the difference btw all-time boost and more optimal mode would've been 1 or 2%, ex. 98% vs 97%.

I didn't read the whole thread - 66 pages is when topics becomes either dated or weer sideways, so can't say about this controller.

[red31]

MrWizard wrote:

I chose that 300 minutes,

smart move for a heavy user making a 3 stage charger 2 stages when the sun shines.

[CA_Traveler]

MrWizard wrote:
I chose that 300 minutes, remember we full-time, I want to maintain voltage not have it drop off, my batteries are Never not being used If the controller went into float and the fridge is on and other things using power It would start discharging the batteries instead of maintaining voltage and amps for the longest possible time
And I chose that 3mv for similar reasons regarding our use

From your description you are over charging the batteries. When the batteries are charged lowering the voltage to float keeps them charged.

When the batteries are charged and you then add house loads the extra amps should be provided by the solar controller provided there is adequate panels and sun. If the Grape controller doesn't do this then get a better controller that does operate in a optimal mode. Full time and battery cycles reduce their life and a better controller is very justified.

[Almot]

Restricting temp comp to 3mv (unless the battery manual suggest this number) you make it run at higher than recommended voltage when it's hot, and at lower voltage when it's cold. Seems counter-intuitive, let battery gurus correct me.

About preventing battery from discharging under loads. As long as the solar is adequate and there is enough sun, it will keep battery in Float, diverting the excess energy to loads at the same time. There will be NO discharging. Sounds like your system is undersized - solar can't keep up after "normal" 100-120 min boost charge. But then again, who can tell exactly when battery should go into Float...

Keeping controller forcefully at 14s half the time, you are trying to push AH into battery by keeping it at higher voltage, kinda similar to how people without solar are trying to achieve this with generator. Not optimal, though I can understand the reasons.

[MrWizard]

The controller does everything
The cell phone is merely a wireless remote for accessing the data and settings
The phone does NOT control the solar

I chose that 300 minutes, remember we full-time, I want to maintain voltage not have it drop off, my batteries are Never not being used
If the controller went into float and the fridge is on and other things using power It would start discharging the batteries instead of maintaining voltage and amps for the longest possible time
And I chose that 3mv for similar reasons regarding our use

[grizzzman]

Almot all adjustments are accessed through the controller. The Bluetooth set up allows adjustment without being at the controller.

[Almot]

Mr Wiz, 2 settings look a little off to me in these photos:
1) 300 minutes Absorption time (if Boost Charge is this?), and
2) 3mv/cell temp comp.

It's nice to have a remote that you can put anywhere, but you are relying on the cell phone to control the solar. Solar should be self-sufficient. Cell phones are not meant to be durable or long lasting, by design. I had mine run out of juice when I was using it as a GPS, and 2-weeks old 12V cig lighter charger died on the same day. In a unfamiliar location, night, bad weather. The phone itself is having hiccups already, 3 years old.

[grizzzman]

Thanks Red

[red31]

controller manual shows li default of 14.4v
http://www.grapesolar.com/docs/GS-PWM-40BT%20manual.pdf

[grizzzman]

MrWizard wrote:
IF i can find a way to save my current settings, so i don't have to re-enter all of them

not sure i can view the lth setting with out it changing my current settings to the LTH settings

OK thanks for looking.

[MrWizard]

IF i can find a way to save my current settings, so i don't have to re-enter all of them

not sure i can view the lth setting with out it changing my current settings to the LTH settings